From 200bf8df7a6879b5c0840cba0b9d620f6b4221b1 Mon Sep 17 00:00:00 2001
From: diharaw <shredhead94@gmail.com>
Date: Wed, 29 Sep 2021 17:05:17 +0100
Subject: [PATCH 01/20] Added gltf2 KHR_materials_volume import support.

---
 code/AssetLib/glTF2/glTF2Asset.h      | 16 ++++++++++++++++
 code/AssetLib/glTF2/glTF2Asset.inl    | 21 +++++++++++++++++++++
 code/AssetLib/glTF2/glTF2Importer.cpp | 10 ++++++++++
 include/assimp/material.h             | 17 +++++++++++++++++
 4 files changed, 64 insertions(+)

diff --git a/code/AssetLib/glTF2/glTF2Asset.h b/code/AssetLib/glTF2/glTF2Asset.h
index 9a50ede99..fb3100b2c 100644
--- a/code/AssetLib/glTF2/glTF2Asset.h
+++ b/code/AssetLib/glTF2/glTF2Asset.h
@@ -49,6 +49,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *   KHR_materials_sheen full
  *   KHR_materials_clearcoat full
  *   KHR_materials_transmission full
+ *   KHR_materials_volume full
  */
 #ifndef GLTF2ASSET_H_INC
 #define GLTF2ASSET_H_INC
@@ -713,6 +714,7 @@ const vec3 defaultEmissiveFactor = { 0, 0, 0 };
 const vec4 defaultDiffuseFactor = { 1, 1, 1, 1 };
 const vec3 defaultSpecularFactor = { 1, 1, 1 };
 const vec3 defaultSheenFactor = { 0, 0, 0 };
+const vec3 defaultAttenuationColor = { 1, 1, 1 };
 
 struct TextureInfo {
     Ref<Texture> texture;
@@ -777,6 +779,16 @@ struct MaterialTransmission {
     float transmissionFactor = 0.f;
 };
 
+struct MaterialVolume {
+    float thicknessFactor = 0.f;
+    TextureInfo thicknessTexture;
+    float attenuationDistance = 0.f;
+    vec3 attenuationColor;
+
+    MaterialVolume() { SetDefaults(); }
+    void SetDefaults();
+};
+
 //! The material appearance of a primitive.
 struct Material : public Object {
     //PBR metallic roughness properties
@@ -803,6 +815,9 @@ struct Material : public Object {
     //extension: KHR_materials_transmission
     Nullable<MaterialTransmission> materialTransmission;
 
+    //extension: KHR_materials_volume
+    Nullable<MaterialVolume> materialVolume;
+    
     //extension: KHR_materials_unlit
     bool unlit;
 
@@ -1091,6 +1106,7 @@ public:
         bool KHR_materials_sheen;
         bool KHR_materials_clearcoat;
         bool KHR_materials_transmission;
+        bool KHR_materials_volume;
         bool KHR_draco_mesh_compression;
         bool FB_ngon_encoding;
         bool KHR_texture_basisu;
diff --git a/code/AssetLib/glTF2/glTF2Asset.inl b/code/AssetLib/glTF2/glTF2Asset.inl
index 4832995cc..ff71ff53b 100644
--- a/code/AssetLib/glTF2/glTF2Asset.inl
+++ b/code/AssetLib/glTF2/glTF2Asset.inl
@@ -1215,6 +1215,19 @@ inline void Material::Read(Value &material, Asset &r) {
             }
         }
 
+        if (r.extensionsUsed.KHR_materials_volume) {
+            if (Value *curMaterialVolume = FindObject(*extensions, "KHR_materials_volume")) {
+                MaterialVolume volume;
+
+                ReadMember(*curMaterialVolume, "thicknessFactor", volume.thicknessFactor);
+                ReadTextureProperty(r, *curMaterialVolume, "thicknessTexture", volume.thicknessTexture);
+                ReadMember(*curMaterialVolume, "attenuationDistance", volume.attenuationDistance);
+                ReadMember(*curMaterialVolume, "attenuationColor", volume.attenuationColor);
+
+                this->materialVolume = Nullable<MaterialVolume>(volume);
+            }
+        }
+
         unlit = nullptr != FindObject(*extensions, "KHR_materials_unlit");
     }
 }
@@ -1260,6 +1273,13 @@ inline void MaterialSheen::SetDefaults() {
     sheenRoughnessFactor = 0.f;
 }
 
+inline void MaterialVolume::SetDefaults() {
+    //KHR_materials_volume properties
+    thicknessFactor = 0.f;
+    attenuationDistance = INFINITY;
+    SetVector(attenuationColor, defaultAttenuationColor);
+}
+
 namespace {
 
 template <int N>
@@ -1931,6 +1951,7 @@ inline void Asset::ReadExtensionsUsed(Document &doc) {
     CHECK_EXT(KHR_materials_sheen);
     CHECK_EXT(KHR_materials_clearcoat);
     CHECK_EXT(KHR_materials_transmission);
+    CHECK_EXT(KHR_materials_volume);
     CHECK_EXT(KHR_draco_mesh_compression);
     CHECK_EXT(KHR_texture_basisu);
 
diff --git a/code/AssetLib/glTF2/glTF2Importer.cpp b/code/AssetLib/glTF2/glTF2Importer.cpp
index 6c92bdc87..136b01d07 100644
--- a/code/AssetLib/glTF2/glTF2Importer.cpp
+++ b/code/AssetLib/glTF2/glTF2Importer.cpp
@@ -341,6 +341,16 @@ static aiMaterial *ImportMaterial(std::vector<int> &embeddedTexIdxs, Asset &r, M
             SetMaterialTextureProperty(embeddedTexIdxs, r, transmission.transmissionTexture, aimat, AI_MATKEY_TRANSMISSION_TEXTURE);
         }
 
+        // KHR_materials_volume
+        if (mat.materialVolume.isPresent) {
+            MaterialVolume &volume = mat.materialVolume.value;
+
+            aimat->AddProperty(&volume.thicknessFactor, 1, AI_MATKEY_VOLUME_THICKNESS_FACTOR);
+            SetMaterialTextureProperty(embeddedTexIdxs, r, volume.thicknessTexture, aimat, AI_MATKEY_VOLUME_THICKNESS_TEXTURE);
+            aimat->AddProperty(&volume.attenuationDistance, 1, AI_MATKEY_VOLUME_ATTENUATION_DISTANCE);
+            SetMaterialColorProperty(r, volume.attenuationColor, aimat, AI_MATKEY_VOLUME_ATTENUATION_COLOR);
+        }
+
         return aimat;
     } catch (...) {
         delete aimat;
diff --git a/include/assimp/material.h b/include/assimp/material.h
index 250ad90d5..2373185fc 100644
--- a/include/assimp/material.h
+++ b/include/assimp/material.h
@@ -318,6 +318,12 @@ enum aiTextureType {
     */
     aiTextureType_TRANSMISSION = 21,
 
+    /** Volume
+    * Simulates transmission through the surface
+    * May include further information such as wall thickness
+    */
+    aiTextureType_VOLUME = 22,
+
     /** Unknown texture
      *
      *  A texture reference that does not match any of the definitions
@@ -1028,6 +1034,17 @@ extern "C" {
 // Multiplied by AI_MATKEY_TRANSMISSION_FACTOR
 #define AI_MATKEY_TRANSMISSION_TEXTURE aiTextureType_TRANSMISSION, 0
 
+// Volume
+// ------------
+// https://github.com/KhronosGroup/glTF/tree/main/extensions/2.0/Khronos/KHR_materials_volume
+// Base percentage of light transmitted through the surface. 0.0 = Opaque, 1.0 = Fully transparent
+#define AI_MATKEY_VOLUME_THICKNESS_FACTOR "$mat.volume.thicknessFactor", 0, 0
+// Texture defining percentage of light transmitted through the surface.
+// Multiplied by AI_MATKEY_THICKNESS_FACTOR
+#define AI_MATKEY_VOLUME_THICKNESS_TEXTURE aiTextureType_VOLUME, 0
+#define AI_MATKEY_VOLUME_ATTENUATION_DISTANCE "$mat.volume.attenuationDistance", 0, 0
+#define AI_MATKEY_VOLUME_ATTENUATION_COLOR "$mat.volume.attenuationColor", 0, 0
+
 // Emissive
 // --------
 #define AI_MATKEY_USE_EMISSIVE_MAP "$mat.useEmissiveMap", 0, 0

From d3276de47da869417b1a619640f534d90e66a6dc Mon Sep 17 00:00:00 2001
From: diharaw <shredhead94@gmail.com>
Date: Thu, 30 Sep 2021 08:10:02 +0100
Subject: [PATCH 02/20] Added gltf2 KHR_materials_volume write support.

---
 code/AssetLib/glTF2/glTF2AssetWriter.h   |  1 +
 code/AssetLib/glTF2/glTF2AssetWriter.inl | 26 ++++++++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/code/AssetLib/glTF2/glTF2AssetWriter.h b/code/AssetLib/glTF2/glTF2AssetWriter.h
index 8244a14b9..9be3fdf0c 100644
--- a/code/AssetLib/glTF2/glTF2AssetWriter.h
+++ b/code/AssetLib/glTF2/glTF2AssetWriter.h
@@ -49,6 +49,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *   KHR_materials_sheen: full
  *   KHR_materials_clearcoat: full
  *   KHR_materials_transmission: full
+ *   KHR_materials_volume: full
  */
 #ifndef GLTF2ASSETWRITER_H_INC
 #define GLTF2ASSETWRITER_H_INC
diff --git a/code/AssetLib/glTF2/glTF2AssetWriter.inl b/code/AssetLib/glTF2/glTF2AssetWriter.inl
index 115cdf903..03b8476dc 100644
--- a/code/AssetLib/glTF2/glTF2AssetWriter.inl
+++ b/code/AssetLib/glTF2/glTF2AssetWriter.inl
@@ -474,6 +474,28 @@ namespace glTF2 {
             }
         }
 
+        if (m.materialVolume.isPresent) {
+            Value materialVolume(rapidjson::Type::kObjectType);
+
+            MaterialVolume &volume = m.materialVolume.value;
+
+            if (volume.thicknessFactor != 0.f) {
+                WriteFloat(materialVolume, volume.thicknessFactor, "thicknessFactor", w.mAl);
+            }
+
+            WriteTex(materialVolume, volume.thicknessTexture, "thicknessTexture", w.mAl);
+
+            if (volume.attenuationDistance != INFINITY) {
+                WriteFloat(materialVolume, volume.attenuationDistance, "attenuationDistance", w.mAl);
+            }
+
+            WriteVec(materialVolume, volume.attenuationColor, "attenuationColor", defaultAttenuationColor, w.mAl);
+
+            if (!materialVolume.ObjectEmpty()) {
+                exts.AddMember("KHR_materials_volume", materialVolume, w.mAl);
+            }
+        }
+
         if (!exts.ObjectEmpty()) {
             obj.AddMember("extensions", exts, w.mAl);
         }
@@ -890,6 +912,10 @@ namespace glTF2 {
                 exts.PushBack(StringRef("KHR_materials_transmission"), mAl);
             }
 
+            if (this->mAsset.extensionsUsed.KHR_materials_volume) {
+                exts.PushBack(StringRef("KHR_materials_volume"), mAl);
+            }
+
             if (this->mAsset.extensionsUsed.FB_ngon_encoding) {
                 exts.PushBack(StringRef("FB_ngon_encoding"), mAl);
             }

From addd54125133c590bcf1dda68ca78f9952651f33 Mon Sep 17 00:00:00 2001
From: diharaw <shredhead94@gmail.com>
Date: Thu, 30 Sep 2021 08:47:53 +0100
Subject: [PATCH 03/20] Added gltf2 KHR_materials_ior support.

---
 code/AssetLib/glTF2/glTF2Asset.h         | 12 ++++++++++
 code/AssetLib/glTF2/glTF2Asset.inl       | 16 ++++++++++++++
 code/AssetLib/glTF2/glTF2AssetWriter.h   |  1 +
 code/AssetLib/glTF2/glTF2AssetWriter.inl | 18 +++++++++++++++
 code/AssetLib/glTF2/glTF2Exporter.cpp    | 28 ++++++++++++++++++++++++
 code/AssetLib/glTF2/glTF2Exporter.h      |  4 ++++
 code/AssetLib/glTF2/glTF2Importer.cpp    |  7 ++++++
 include/assimp/material.h                | 12 ++++++++--
 8 files changed, 96 insertions(+), 2 deletions(-)

diff --git a/code/AssetLib/glTF2/glTF2Asset.h b/code/AssetLib/glTF2/glTF2Asset.h
index fb3100b2c..c790a1374 100644
--- a/code/AssetLib/glTF2/glTF2Asset.h
+++ b/code/AssetLib/glTF2/glTF2Asset.h
@@ -50,6 +50,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *   KHR_materials_clearcoat full
  *   KHR_materials_transmission full
  *   KHR_materials_volume full
+ *   KHR_materials_ior full
  */
 #ifndef GLTF2ASSET_H_INC
 #define GLTF2ASSET_H_INC
@@ -789,6 +790,13 @@ struct MaterialVolume {
     void SetDefaults();
 };
 
+struct MaterialIOR {
+    float ior = 0.f;
+
+    MaterialIOR() { SetDefaults(); }
+    void SetDefaults();
+};
+
 //! The material appearance of a primitive.
 struct Material : public Object {
     //PBR metallic roughness properties
@@ -817,6 +825,9 @@ struct Material : public Object {
 
     //extension: KHR_materials_volume
     Nullable<MaterialVolume> materialVolume;
+
+    //extension: KHR_materials_ior
+    Nullable<MaterialIOR> materialIOR;
     
     //extension: KHR_materials_unlit
     bool unlit;
@@ -1107,6 +1118,7 @@ public:
         bool KHR_materials_clearcoat;
         bool KHR_materials_transmission;
         bool KHR_materials_volume;
+        bool KHR_materials_ior;
         bool KHR_draco_mesh_compression;
         bool FB_ngon_encoding;
         bool KHR_texture_basisu;
diff --git a/code/AssetLib/glTF2/glTF2Asset.inl b/code/AssetLib/glTF2/glTF2Asset.inl
index ff71ff53b..d65b4132b 100644
--- a/code/AssetLib/glTF2/glTF2Asset.inl
+++ b/code/AssetLib/glTF2/glTF2Asset.inl
@@ -1228,6 +1228,16 @@ inline void Material::Read(Value &material, Asset &r) {
             }
         }
 
+        if (r.extensionsUsed.KHR_materials_ior) {
+            if (Value *curMaterialIOR = FindObject(*extensions, "KHR_materials_ior")) {
+                MaterialIOR ior;
+
+                ReadMember(*curMaterialIOR, "ior", ior.ior);
+          
+                this->materialIOR = Nullable<MaterialIOR>(ior);
+            }
+        }
+
         unlit = nullptr != FindObject(*extensions, "KHR_materials_unlit");
     }
 }
@@ -1280,6 +1290,11 @@ inline void MaterialVolume::SetDefaults() {
     SetVector(attenuationColor, defaultAttenuationColor);
 }
 
+inline void MaterialIOR::SetDefaults() {
+    //KHR_materials_ior properties
+    ior = 1.5f;
+}
+
 namespace {
 
 template <int N>
@@ -1952,6 +1967,7 @@ inline void Asset::ReadExtensionsUsed(Document &doc) {
     CHECK_EXT(KHR_materials_clearcoat);
     CHECK_EXT(KHR_materials_transmission);
     CHECK_EXT(KHR_materials_volume);
+    CHECK_EXT(KHR_materials_ior);
     CHECK_EXT(KHR_draco_mesh_compression);
     CHECK_EXT(KHR_texture_basisu);
 
diff --git a/code/AssetLib/glTF2/glTF2AssetWriter.h b/code/AssetLib/glTF2/glTF2AssetWriter.h
index 9be3fdf0c..ce8b4d65e 100644
--- a/code/AssetLib/glTF2/glTF2AssetWriter.h
+++ b/code/AssetLib/glTF2/glTF2AssetWriter.h
@@ -50,6 +50,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *   KHR_materials_clearcoat: full
  *   KHR_materials_transmission: full
  *   KHR_materials_volume: full
+ *   KHR_materials_ior: full
  */
 #ifndef GLTF2ASSETWRITER_H_INC
 #define GLTF2ASSETWRITER_H_INC
diff --git a/code/AssetLib/glTF2/glTF2AssetWriter.inl b/code/AssetLib/glTF2/glTF2AssetWriter.inl
index 03b8476dc..b91553fbe 100644
--- a/code/AssetLib/glTF2/glTF2AssetWriter.inl
+++ b/code/AssetLib/glTF2/glTF2AssetWriter.inl
@@ -496,6 +496,20 @@ namespace glTF2 {
             }
         }
 
+        if (m.materialIOR.isPresent) {
+            Value materialIOR(rapidjson::Type::kObjectType);
+
+            MaterialIOR &ior = m.materialIOR.value;
+
+            if (ior.ior != 1.5f) {
+                WriteFloat(materialIOR, ior.ior, "ior", w.mAl);
+            }
+
+            if (!materialIOR.ObjectEmpty()) {
+                exts.AddMember("KHR_materials_ior", materialIOR, w.mAl);
+            }
+        }
+
         if (!exts.ObjectEmpty()) {
             obj.AddMember("extensions", exts, w.mAl);
         }
@@ -916,6 +930,10 @@ namespace glTF2 {
                 exts.PushBack(StringRef("KHR_materials_volume"), mAl);
             }
 
+            if (this->mAsset.extensionsUsed.KHR_materials_ior) {
+                exts.PushBack(StringRef("KHR_materials_ior"), mAl);
+            }
+
             if (this->mAsset.extensionsUsed.FB_ngon_encoding) {
                 exts.PushBack(StringRef("FB_ngon_encoding"), mAl);
             }
diff --git a/code/AssetLib/glTF2/glTF2Exporter.cpp b/code/AssetLib/glTF2/glTF2Exporter.cpp
index 22db4b26d..8327f8c54 100644
--- a/code/AssetLib/glTF2/glTF2Exporter.cpp
+++ b/code/AssetLib/glTF2/glTF2Exporter.cpp
@@ -704,6 +704,22 @@ bool glTF2Exporter::GetMatTransmission(const aiMaterial &mat, glTF2::MaterialTra
     return result || transmission.transmissionTexture.texture;
 }
 
+bool glTF2Exporter::GetMatVolume(const aiMaterial &mat, glTF2::MaterialVolume &volume) {
+    bool result = mat.Get(AI_MATKEY_VOLUME_THICKNESS_FACTOR, volume.thicknessFactor) != aiReturn_SUCCESS;
+
+    GetMatTex(mat, volume.thicknessTexture, AI_MATKEY_VOLUME_THICKNESS_TEXTURE);
+
+    result = result || mat.Get(AI_MATKEY_VOLUME_ATTENUATION_DISTANCE, volume.attenuationDistance);
+    result = result || GetMatColor(mat, volume.attenuationColor, AI_MATKEY_VOLUME_ATTENUATION_COLOR) != aiReturn_SUCCESS;
+
+    // Valid if any of these properties are available
+    return result || volume.thicknessTexture.texture;
+}
+
+bool glTF2Exporter::GetMatIOR(const aiMaterial &mat, glTF2::MaterialIOR &ior) {
+    return mat.Get(AI_MATKEY_IOR, ior.ior) == aiReturn_SUCCESS;
+}
+
 void glTF2Exporter::ExportMaterials() {
     aiString aiName;
     for (unsigned int i = 0; i < mScene->mNumMaterials; ++i) {
@@ -824,6 +840,18 @@ void glTF2Exporter::ExportMaterials() {
                     mAsset->extensionsUsed.KHR_materials_transmission = true;
                     m->materialTransmission = Nullable<MaterialTransmission>(transmission);
                 }
+                
+                MaterialVolume volume;
+                if (GetMatVolume(mat, volume)) {
+                    mAsset->extensionsUsed.KHR_materials_volume = true;
+                    m->materialVolume = Nullable<MaterialVolume>(volume);
+                }
+                                
+                MaterialIOR ior;
+                if (GetMatIOR(mat, ior)) {
+                    mAsset->extensionsUsed.KHR_materials_ior = true;
+                    m->materialIOR = Nullable<MaterialIOR>(ior);
+                }
             }
         }
     }
diff --git a/code/AssetLib/glTF2/glTF2Exporter.h b/code/AssetLib/glTF2/glTF2Exporter.h
index 842d29815..6d70d915e 100644
--- a/code/AssetLib/glTF2/glTF2Exporter.h
+++ b/code/AssetLib/glTF2/glTF2Exporter.h
@@ -77,6 +77,8 @@ struct PbrSpecularGlossiness;
 struct MaterialSheen;
 struct MaterialClearcoat;
 struct MaterialTransmission;
+struct MaterialVolume;
+struct MaterialIOR;
 
 // Vec/matrix types, as raw float arrays
 typedef float(vec2)[2];
@@ -114,6 +116,8 @@ protected:
     bool GetMatSheen(const aiMaterial &mat, glTF2::MaterialSheen &sheen);
     bool GetMatClearcoat(const aiMaterial &mat, glTF2::MaterialClearcoat &clearcoat);
     bool GetMatTransmission(const aiMaterial &mat, glTF2::MaterialTransmission &transmission);
+    bool GetMatVolume(const aiMaterial &mat, glTF2::MaterialVolume &volume);
+    bool GetMatIOR(const aiMaterial &mat, glTF2::MaterialIOR &ior);
     void ExportMetadata();
     void ExportMaterials();
     void ExportMeshes();
diff --git a/code/AssetLib/glTF2/glTF2Importer.cpp b/code/AssetLib/glTF2/glTF2Importer.cpp
index 136b01d07..c7de2af4f 100644
--- a/code/AssetLib/glTF2/glTF2Importer.cpp
+++ b/code/AssetLib/glTF2/glTF2Importer.cpp
@@ -351,6 +351,13 @@ static aiMaterial *ImportMaterial(std::vector<int> &embeddedTexIdxs, Asset &r, M
             SetMaterialColorProperty(r, volume.attenuationColor, aimat, AI_MATKEY_VOLUME_ATTENUATION_COLOR);
         }
 
+        // KHR_materials_ior
+        if (mat.materialIOR.isPresent) {
+            MaterialIOR &ior = mat.materialIOR.value;
+
+            aimat->AddProperty(&ior.ior, 1, AI_MATKEY_IOR);
+        }
+
         return aimat;
     } catch (...) {
         delete aimat;
diff --git a/include/assimp/material.h b/include/assimp/material.h
index 2373185fc..c86848993 100644
--- a/include/assimp/material.h
+++ b/include/assimp/material.h
@@ -1037,14 +1037,22 @@ extern "C" {
 // Volume
 // ------------
 // https://github.com/KhronosGroup/glTF/tree/main/extensions/2.0/Khronos/KHR_materials_volume
-// Base percentage of light transmitted through the surface. 0.0 = Opaque, 1.0 = Fully transparent
+// The thickness of the volume beneath the surface. If the value is 0 the material is thin-walled. Otherwise the material is a volume boundary.
 #define AI_MATKEY_VOLUME_THICKNESS_FACTOR "$mat.volume.thicknessFactor", 0, 0
-// Texture defining percentage of light transmitted through the surface.
+// Texture that defines the thickness.
 // Multiplied by AI_MATKEY_THICKNESS_FACTOR
 #define AI_MATKEY_VOLUME_THICKNESS_TEXTURE aiTextureType_VOLUME, 0
+// Density of the medium given as the average distance that light travels in the medium before interacting with a particle.
 #define AI_MATKEY_VOLUME_ATTENUATION_DISTANCE "$mat.volume.attenuationDistance", 0, 0
+// The color that white light turns into due to absorption when reaching the attenuation distance.
 #define AI_MATKEY_VOLUME_ATTENUATION_COLOR "$mat.volume.attenuationColor", 0, 0
 
+// IOR
+// ------------
+// https://github.com/KhronosGroup/glTF/tree/main/extensions/2.0/Khronos/KHR_materials_ior
+// Index of Refraction.
+#define AI_MATKEY_IOR "$mat.ior", 0, 0
+
 // Emissive
 // --------
 #define AI_MATKEY_USE_EMISSIVE_MAP "$mat.useEmissiveMap", 0, 0

From 46a7de7a0b21ebf03c8128fb3952db4c4d670228 Mon Sep 17 00:00:00 2001
From: diharaw <shredhead94@gmail.com>
Date: Thu, 30 Sep 2021 08:56:16 +0100
Subject: [PATCH 04/20] Moved KHR_material_volume thickness texture under
 aiTextureType_TRANSMISSION.

---
 include/assimp/material.h | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/include/assimp/material.h b/include/assimp/material.h
index c86848993..5499bd916 100644
--- a/include/assimp/material.h
+++ b/include/assimp/material.h
@@ -318,12 +318,6 @@ enum aiTextureType {
     */
     aiTextureType_TRANSMISSION = 21,
 
-    /** Volume
-    * Simulates transmission through the surface
-    * May include further information such as wall thickness
-    */
-    aiTextureType_VOLUME = 22,
-
     /** Unknown texture
      *
      *  A texture reference that does not match any of the definitions
@@ -1041,7 +1035,7 @@ extern "C" {
 #define AI_MATKEY_VOLUME_THICKNESS_FACTOR "$mat.volume.thicknessFactor", 0, 0
 // Texture that defines the thickness.
 // Multiplied by AI_MATKEY_THICKNESS_FACTOR
-#define AI_MATKEY_VOLUME_THICKNESS_TEXTURE aiTextureType_VOLUME, 0
+#define AI_MATKEY_VOLUME_THICKNESS_TEXTURE aiTextureType_TRANSMISSION, 1
 // Density of the medium given as the average distance that light travels in the medium before interacting with a particle.
 #define AI_MATKEY_VOLUME_ATTENUATION_DISTANCE "$mat.volume.attenuationDistance", 0, 0
 // The color that white light turns into due to absorption when reaching the attenuation distance.

From 656b0b25d869d2fe243b3fadfb422b3b6475e559 Mon Sep 17 00:00:00 2001
From: Marc <marc@texcube.net>
Date: Tue, 5 Oct 2021 19:24:42 +0200
Subject: [PATCH 05/20] Fix warning for array comparison

The code previously compared two float arrays with the != operator. This is deprecated in Visual Studio 2019 and results in a warning that leads to an error when compiling with warnings as errors. Small fix to make the build work.
---
 code/AssetLib/glTF2/glTF2Importer.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/code/AssetLib/glTF2/glTF2Importer.cpp b/code/AssetLib/glTF2/glTF2Importer.cpp
index 6c92bdc87..dca32f22b 100644
--- a/code/AssetLib/glTF2/glTF2Importer.cpp
+++ b/code/AssetLib/glTF2/glTF2Importer.cpp
@@ -312,7 +312,7 @@ static aiMaterial *ImportMaterial(std::vector<int> &embeddedTexIdxs, Asset &r, M
         if (mat.materialSheen.isPresent) {
             MaterialSheen &sheen = mat.materialSheen.value;
             // Default value {0,0,0} disables Sheen
-            if (sheen.sheenColorFactor != defaultSheenFactor) {
+            if (std::memcmp(sheen.sheenColorFactor, defaultSheenFactor, sizeof(glTFCommon::vec3)) != 0) {
                 SetMaterialColorProperty(r, sheen.sheenColorFactor, aimat, AI_MATKEY_SHEEN_COLOR_FACTOR);
                 aimat->AddProperty(&sheen.sheenRoughnessFactor, 1, AI_MATKEY_SHEEN_ROUGHNESS_FACTOR);
                 SetMaterialTextureProperty(embeddedTexIdxs, r, sheen.sheenColorTexture, aimat, AI_MATKEY_SHEEN_COLOR_TEXTURE);

From 0738742611dba94d9adef998e59df963ba8c4115 Mon Sep 17 00:00:00 2001
From: diharaw <shredhead94@gmail.com>
Date: Thu, 7 Oct 2021 09:30:22 +0100
Subject: [PATCH 06/20] Removed KHR_materials_ior support.

---
 code/AssetLib/glTF2/glTF2Asset.h         | 12 ------------
 code/AssetLib/glTF2/glTF2Asset.inl       | 16 ----------------
 code/AssetLib/glTF2/glTF2AssetWriter.h   |  1 -
 code/AssetLib/glTF2/glTF2AssetWriter.inl | 18 ------------------
 code/AssetLib/glTF2/glTF2Exporter.cpp    | 10 ----------
 code/AssetLib/glTF2/glTF2Exporter.h      |  2 --
 code/AssetLib/glTF2/glTF2Importer.cpp    |  7 -------
 include/assimp/material.h                |  6 ------
 8 files changed, 72 deletions(-)

diff --git a/code/AssetLib/glTF2/glTF2Asset.h b/code/AssetLib/glTF2/glTF2Asset.h
index c790a1374..e97523bbe 100644
--- a/code/AssetLib/glTF2/glTF2Asset.h
+++ b/code/AssetLib/glTF2/glTF2Asset.h
@@ -50,7 +50,6 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *   KHR_materials_clearcoat full
  *   KHR_materials_transmission full
  *   KHR_materials_volume full
- *   KHR_materials_ior full
  */
 #ifndef GLTF2ASSET_H_INC
 #define GLTF2ASSET_H_INC
@@ -790,13 +789,6 @@ struct MaterialVolume {
     void SetDefaults();
 };
 
-struct MaterialIOR {
-    float ior = 0.f;
-
-    MaterialIOR() { SetDefaults(); }
-    void SetDefaults();
-};
-
 //! The material appearance of a primitive.
 struct Material : public Object {
     //PBR metallic roughness properties
@@ -826,9 +818,6 @@ struct Material : public Object {
     //extension: KHR_materials_volume
     Nullable<MaterialVolume> materialVolume;
 
-    //extension: KHR_materials_ior
-    Nullable<MaterialIOR> materialIOR;
-    
     //extension: KHR_materials_unlit
     bool unlit;
 
@@ -1118,7 +1107,6 @@ public:
         bool KHR_materials_clearcoat;
         bool KHR_materials_transmission;
         bool KHR_materials_volume;
-        bool KHR_materials_ior;
         bool KHR_draco_mesh_compression;
         bool FB_ngon_encoding;
         bool KHR_texture_basisu;
diff --git a/code/AssetLib/glTF2/glTF2Asset.inl b/code/AssetLib/glTF2/glTF2Asset.inl
index d65b4132b..ff71ff53b 100644
--- a/code/AssetLib/glTF2/glTF2Asset.inl
+++ b/code/AssetLib/glTF2/glTF2Asset.inl
@@ -1228,16 +1228,6 @@ inline void Material::Read(Value &material, Asset &r) {
             }
         }
 
-        if (r.extensionsUsed.KHR_materials_ior) {
-            if (Value *curMaterialIOR = FindObject(*extensions, "KHR_materials_ior")) {
-                MaterialIOR ior;
-
-                ReadMember(*curMaterialIOR, "ior", ior.ior);
-          
-                this->materialIOR = Nullable<MaterialIOR>(ior);
-            }
-        }
-
         unlit = nullptr != FindObject(*extensions, "KHR_materials_unlit");
     }
 }
@@ -1290,11 +1280,6 @@ inline void MaterialVolume::SetDefaults() {
     SetVector(attenuationColor, defaultAttenuationColor);
 }
 
-inline void MaterialIOR::SetDefaults() {
-    //KHR_materials_ior properties
-    ior = 1.5f;
-}
-
 namespace {
 
 template <int N>
@@ -1967,7 +1952,6 @@ inline void Asset::ReadExtensionsUsed(Document &doc) {
     CHECK_EXT(KHR_materials_clearcoat);
     CHECK_EXT(KHR_materials_transmission);
     CHECK_EXT(KHR_materials_volume);
-    CHECK_EXT(KHR_materials_ior);
     CHECK_EXT(KHR_draco_mesh_compression);
     CHECK_EXT(KHR_texture_basisu);
 
diff --git a/code/AssetLib/glTF2/glTF2AssetWriter.h b/code/AssetLib/glTF2/glTF2AssetWriter.h
index ce8b4d65e..9be3fdf0c 100644
--- a/code/AssetLib/glTF2/glTF2AssetWriter.h
+++ b/code/AssetLib/glTF2/glTF2AssetWriter.h
@@ -50,7 +50,6 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *   KHR_materials_clearcoat: full
  *   KHR_materials_transmission: full
  *   KHR_materials_volume: full
- *   KHR_materials_ior: full
  */
 #ifndef GLTF2ASSETWRITER_H_INC
 #define GLTF2ASSETWRITER_H_INC
diff --git a/code/AssetLib/glTF2/glTF2AssetWriter.inl b/code/AssetLib/glTF2/glTF2AssetWriter.inl
index b91553fbe..03b8476dc 100644
--- a/code/AssetLib/glTF2/glTF2AssetWriter.inl
+++ b/code/AssetLib/glTF2/glTF2AssetWriter.inl
@@ -496,20 +496,6 @@ namespace glTF2 {
             }
         }
 
-        if (m.materialIOR.isPresent) {
-            Value materialIOR(rapidjson::Type::kObjectType);
-
-            MaterialIOR &ior = m.materialIOR.value;
-
-            if (ior.ior != 1.5f) {
-                WriteFloat(materialIOR, ior.ior, "ior", w.mAl);
-            }
-
-            if (!materialIOR.ObjectEmpty()) {
-                exts.AddMember("KHR_materials_ior", materialIOR, w.mAl);
-            }
-        }
-
         if (!exts.ObjectEmpty()) {
             obj.AddMember("extensions", exts, w.mAl);
         }
@@ -930,10 +916,6 @@ namespace glTF2 {
                 exts.PushBack(StringRef("KHR_materials_volume"), mAl);
             }
 
-            if (this->mAsset.extensionsUsed.KHR_materials_ior) {
-                exts.PushBack(StringRef("KHR_materials_ior"), mAl);
-            }
-
             if (this->mAsset.extensionsUsed.FB_ngon_encoding) {
                 exts.PushBack(StringRef("FB_ngon_encoding"), mAl);
             }
diff --git a/code/AssetLib/glTF2/glTF2Exporter.cpp b/code/AssetLib/glTF2/glTF2Exporter.cpp
index 8327f8c54..46433fc95 100644
--- a/code/AssetLib/glTF2/glTF2Exporter.cpp
+++ b/code/AssetLib/glTF2/glTF2Exporter.cpp
@@ -716,10 +716,6 @@ bool glTF2Exporter::GetMatVolume(const aiMaterial &mat, glTF2::MaterialVolume &v
     return result || volume.thicknessTexture.texture;
 }
 
-bool glTF2Exporter::GetMatIOR(const aiMaterial &mat, glTF2::MaterialIOR &ior) {
-    return mat.Get(AI_MATKEY_IOR, ior.ior) == aiReturn_SUCCESS;
-}
-
 void glTF2Exporter::ExportMaterials() {
     aiString aiName;
     for (unsigned int i = 0; i < mScene->mNumMaterials; ++i) {
@@ -846,12 +842,6 @@ void glTF2Exporter::ExportMaterials() {
                     mAsset->extensionsUsed.KHR_materials_volume = true;
                     m->materialVolume = Nullable<MaterialVolume>(volume);
                 }
-                                
-                MaterialIOR ior;
-                if (GetMatIOR(mat, ior)) {
-                    mAsset->extensionsUsed.KHR_materials_ior = true;
-                    m->materialIOR = Nullable<MaterialIOR>(ior);
-                }
             }
         }
     }
diff --git a/code/AssetLib/glTF2/glTF2Exporter.h b/code/AssetLib/glTF2/glTF2Exporter.h
index 6d70d915e..c00faafb9 100644
--- a/code/AssetLib/glTF2/glTF2Exporter.h
+++ b/code/AssetLib/glTF2/glTF2Exporter.h
@@ -78,7 +78,6 @@ struct MaterialSheen;
 struct MaterialClearcoat;
 struct MaterialTransmission;
 struct MaterialVolume;
-struct MaterialIOR;
 
 // Vec/matrix types, as raw float arrays
 typedef float(vec2)[2];
@@ -117,7 +116,6 @@ protected:
     bool GetMatClearcoat(const aiMaterial &mat, glTF2::MaterialClearcoat &clearcoat);
     bool GetMatTransmission(const aiMaterial &mat, glTF2::MaterialTransmission &transmission);
     bool GetMatVolume(const aiMaterial &mat, glTF2::MaterialVolume &volume);
-    bool GetMatIOR(const aiMaterial &mat, glTF2::MaterialIOR &ior);
     void ExportMetadata();
     void ExportMaterials();
     void ExportMeshes();
diff --git a/code/AssetLib/glTF2/glTF2Importer.cpp b/code/AssetLib/glTF2/glTF2Importer.cpp
index c7de2af4f..136b01d07 100644
--- a/code/AssetLib/glTF2/glTF2Importer.cpp
+++ b/code/AssetLib/glTF2/glTF2Importer.cpp
@@ -351,13 +351,6 @@ static aiMaterial *ImportMaterial(std::vector<int> &embeddedTexIdxs, Asset &r, M
             SetMaterialColorProperty(r, volume.attenuationColor, aimat, AI_MATKEY_VOLUME_ATTENUATION_COLOR);
         }
 
-        // KHR_materials_ior
-        if (mat.materialIOR.isPresent) {
-            MaterialIOR &ior = mat.materialIOR.value;
-
-            aimat->AddProperty(&ior.ior, 1, AI_MATKEY_IOR);
-        }
-
         return aimat;
     } catch (...) {
         delete aimat;
diff --git a/include/assimp/material.h b/include/assimp/material.h
index 5499bd916..4e55e4894 100644
--- a/include/assimp/material.h
+++ b/include/assimp/material.h
@@ -1041,12 +1041,6 @@ extern "C" {
 // The color that white light turns into due to absorption when reaching the attenuation distance.
 #define AI_MATKEY_VOLUME_ATTENUATION_COLOR "$mat.volume.attenuationColor", 0, 0
 
-// IOR
-// ------------
-// https://github.com/KhronosGroup/glTF/tree/main/extensions/2.0/Khronos/KHR_materials_ior
-// Index of Refraction.
-#define AI_MATKEY_IOR "$mat.ior", 0, 0
-
 // Emissive
 // --------
 #define AI_MATKEY_USE_EMISSIVE_MAP "$mat.useEmissiveMap", 0, 0

From b01d008bc0d8042bd2395be4b0a8b0bb2eaaa0c6 Mon Sep 17 00:00:00 2001
From: diharaw <shredhead94@gmail.com>
Date: Thu, 7 Oct 2021 09:36:53 +0100
Subject: [PATCH 07/20] Revert "Removed KHR_materials_ior support."

This reverts commit 0738742611dba94d9adef998e59df963ba8c4115.
---
 code/AssetLib/glTF2/glTF2Asset.h         | 12 ++++++++++++
 code/AssetLib/glTF2/glTF2Asset.inl       | 16 ++++++++++++++++
 code/AssetLib/glTF2/glTF2AssetWriter.h   |  1 +
 code/AssetLib/glTF2/glTF2AssetWriter.inl | 18 ++++++++++++++++++
 code/AssetLib/glTF2/glTF2Exporter.cpp    | 10 ++++++++++
 code/AssetLib/glTF2/glTF2Exporter.h      |  2 ++
 code/AssetLib/glTF2/glTF2Importer.cpp    |  7 +++++++
 include/assimp/material.h                |  6 ++++++
 8 files changed, 72 insertions(+)

diff --git a/code/AssetLib/glTF2/glTF2Asset.h b/code/AssetLib/glTF2/glTF2Asset.h
index e97523bbe..c790a1374 100644
--- a/code/AssetLib/glTF2/glTF2Asset.h
+++ b/code/AssetLib/glTF2/glTF2Asset.h
@@ -50,6 +50,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *   KHR_materials_clearcoat full
  *   KHR_materials_transmission full
  *   KHR_materials_volume full
+ *   KHR_materials_ior full
  */
 #ifndef GLTF2ASSET_H_INC
 #define GLTF2ASSET_H_INC
@@ -789,6 +790,13 @@ struct MaterialVolume {
     void SetDefaults();
 };
 
+struct MaterialIOR {
+    float ior = 0.f;
+
+    MaterialIOR() { SetDefaults(); }
+    void SetDefaults();
+};
+
 //! The material appearance of a primitive.
 struct Material : public Object {
     //PBR metallic roughness properties
@@ -818,6 +826,9 @@ struct Material : public Object {
     //extension: KHR_materials_volume
     Nullable<MaterialVolume> materialVolume;
 
+    //extension: KHR_materials_ior
+    Nullable<MaterialIOR> materialIOR;
+    
     //extension: KHR_materials_unlit
     bool unlit;
 
@@ -1107,6 +1118,7 @@ public:
         bool KHR_materials_clearcoat;
         bool KHR_materials_transmission;
         bool KHR_materials_volume;
+        bool KHR_materials_ior;
         bool KHR_draco_mesh_compression;
         bool FB_ngon_encoding;
         bool KHR_texture_basisu;
diff --git a/code/AssetLib/glTF2/glTF2Asset.inl b/code/AssetLib/glTF2/glTF2Asset.inl
index ff71ff53b..d65b4132b 100644
--- a/code/AssetLib/glTF2/glTF2Asset.inl
+++ b/code/AssetLib/glTF2/glTF2Asset.inl
@@ -1228,6 +1228,16 @@ inline void Material::Read(Value &material, Asset &r) {
             }
         }
 
+        if (r.extensionsUsed.KHR_materials_ior) {
+            if (Value *curMaterialIOR = FindObject(*extensions, "KHR_materials_ior")) {
+                MaterialIOR ior;
+
+                ReadMember(*curMaterialIOR, "ior", ior.ior);
+          
+                this->materialIOR = Nullable<MaterialIOR>(ior);
+            }
+        }
+
         unlit = nullptr != FindObject(*extensions, "KHR_materials_unlit");
     }
 }
@@ -1280,6 +1290,11 @@ inline void MaterialVolume::SetDefaults() {
     SetVector(attenuationColor, defaultAttenuationColor);
 }
 
+inline void MaterialIOR::SetDefaults() {
+    //KHR_materials_ior properties
+    ior = 1.5f;
+}
+
 namespace {
 
 template <int N>
@@ -1952,6 +1967,7 @@ inline void Asset::ReadExtensionsUsed(Document &doc) {
     CHECK_EXT(KHR_materials_clearcoat);
     CHECK_EXT(KHR_materials_transmission);
     CHECK_EXT(KHR_materials_volume);
+    CHECK_EXT(KHR_materials_ior);
     CHECK_EXT(KHR_draco_mesh_compression);
     CHECK_EXT(KHR_texture_basisu);
 
diff --git a/code/AssetLib/glTF2/glTF2AssetWriter.h b/code/AssetLib/glTF2/glTF2AssetWriter.h
index 9be3fdf0c..ce8b4d65e 100644
--- a/code/AssetLib/glTF2/glTF2AssetWriter.h
+++ b/code/AssetLib/glTF2/glTF2AssetWriter.h
@@ -50,6 +50,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *   KHR_materials_clearcoat: full
  *   KHR_materials_transmission: full
  *   KHR_materials_volume: full
+ *   KHR_materials_ior: full
  */
 #ifndef GLTF2ASSETWRITER_H_INC
 #define GLTF2ASSETWRITER_H_INC
diff --git a/code/AssetLib/glTF2/glTF2AssetWriter.inl b/code/AssetLib/glTF2/glTF2AssetWriter.inl
index 03b8476dc..b91553fbe 100644
--- a/code/AssetLib/glTF2/glTF2AssetWriter.inl
+++ b/code/AssetLib/glTF2/glTF2AssetWriter.inl
@@ -496,6 +496,20 @@ namespace glTF2 {
             }
         }
 
+        if (m.materialIOR.isPresent) {
+            Value materialIOR(rapidjson::Type::kObjectType);
+
+            MaterialIOR &ior = m.materialIOR.value;
+
+            if (ior.ior != 1.5f) {
+                WriteFloat(materialIOR, ior.ior, "ior", w.mAl);
+            }
+
+            if (!materialIOR.ObjectEmpty()) {
+                exts.AddMember("KHR_materials_ior", materialIOR, w.mAl);
+            }
+        }
+
         if (!exts.ObjectEmpty()) {
             obj.AddMember("extensions", exts, w.mAl);
         }
@@ -916,6 +930,10 @@ namespace glTF2 {
                 exts.PushBack(StringRef("KHR_materials_volume"), mAl);
             }
 
+            if (this->mAsset.extensionsUsed.KHR_materials_ior) {
+                exts.PushBack(StringRef("KHR_materials_ior"), mAl);
+            }
+
             if (this->mAsset.extensionsUsed.FB_ngon_encoding) {
                 exts.PushBack(StringRef("FB_ngon_encoding"), mAl);
             }
diff --git a/code/AssetLib/glTF2/glTF2Exporter.cpp b/code/AssetLib/glTF2/glTF2Exporter.cpp
index 46433fc95..8327f8c54 100644
--- a/code/AssetLib/glTF2/glTF2Exporter.cpp
+++ b/code/AssetLib/glTF2/glTF2Exporter.cpp
@@ -716,6 +716,10 @@ bool glTF2Exporter::GetMatVolume(const aiMaterial &mat, glTF2::MaterialVolume &v
     return result || volume.thicknessTexture.texture;
 }
 
+bool glTF2Exporter::GetMatIOR(const aiMaterial &mat, glTF2::MaterialIOR &ior) {
+    return mat.Get(AI_MATKEY_IOR, ior.ior) == aiReturn_SUCCESS;
+}
+
 void glTF2Exporter::ExportMaterials() {
     aiString aiName;
     for (unsigned int i = 0; i < mScene->mNumMaterials; ++i) {
@@ -842,6 +846,12 @@ void glTF2Exporter::ExportMaterials() {
                     mAsset->extensionsUsed.KHR_materials_volume = true;
                     m->materialVolume = Nullable<MaterialVolume>(volume);
                 }
+                                
+                MaterialIOR ior;
+                if (GetMatIOR(mat, ior)) {
+                    mAsset->extensionsUsed.KHR_materials_ior = true;
+                    m->materialIOR = Nullable<MaterialIOR>(ior);
+                }
             }
         }
     }
diff --git a/code/AssetLib/glTF2/glTF2Exporter.h b/code/AssetLib/glTF2/glTF2Exporter.h
index c00faafb9..6d70d915e 100644
--- a/code/AssetLib/glTF2/glTF2Exporter.h
+++ b/code/AssetLib/glTF2/glTF2Exporter.h
@@ -78,6 +78,7 @@ struct MaterialSheen;
 struct MaterialClearcoat;
 struct MaterialTransmission;
 struct MaterialVolume;
+struct MaterialIOR;
 
 // Vec/matrix types, as raw float arrays
 typedef float(vec2)[2];
@@ -116,6 +117,7 @@ protected:
     bool GetMatClearcoat(const aiMaterial &mat, glTF2::MaterialClearcoat &clearcoat);
     bool GetMatTransmission(const aiMaterial &mat, glTF2::MaterialTransmission &transmission);
     bool GetMatVolume(const aiMaterial &mat, glTF2::MaterialVolume &volume);
+    bool GetMatIOR(const aiMaterial &mat, glTF2::MaterialIOR &ior);
     void ExportMetadata();
     void ExportMaterials();
     void ExportMeshes();
diff --git a/code/AssetLib/glTF2/glTF2Importer.cpp b/code/AssetLib/glTF2/glTF2Importer.cpp
index 136b01d07..c7de2af4f 100644
--- a/code/AssetLib/glTF2/glTF2Importer.cpp
+++ b/code/AssetLib/glTF2/glTF2Importer.cpp
@@ -351,6 +351,13 @@ static aiMaterial *ImportMaterial(std::vector<int> &embeddedTexIdxs, Asset &r, M
             SetMaterialColorProperty(r, volume.attenuationColor, aimat, AI_MATKEY_VOLUME_ATTENUATION_COLOR);
         }
 
+        // KHR_materials_ior
+        if (mat.materialIOR.isPresent) {
+            MaterialIOR &ior = mat.materialIOR.value;
+
+            aimat->AddProperty(&ior.ior, 1, AI_MATKEY_IOR);
+        }
+
         return aimat;
     } catch (...) {
         delete aimat;
diff --git a/include/assimp/material.h b/include/assimp/material.h
index 4e55e4894..5499bd916 100644
--- a/include/assimp/material.h
+++ b/include/assimp/material.h
@@ -1041,6 +1041,12 @@ extern "C" {
 // The color that white light turns into due to absorption when reaching the attenuation distance.
 #define AI_MATKEY_VOLUME_ATTENUATION_COLOR "$mat.volume.attenuationColor", 0, 0
 
+// IOR
+// ------------
+// https://github.com/KhronosGroup/glTF/tree/main/extensions/2.0/Khronos/KHR_materials_ior
+// Index of Refraction.
+#define AI_MATKEY_IOR "$mat.ior", 0, 0
+
 // Emissive
 // --------
 #define AI_MATKEY_USE_EMISSIVE_MAP "$mat.useEmissiveMap", 0, 0

From 0fb66f84378ef441977fd552b6cda2ff3dd7216d Mon Sep 17 00:00:00 2001
From: diharaw <shredhead94@gmail.com>
Date: Thu, 7 Oct 2021 09:39:08 +0100
Subject: [PATCH 08/20] Replaced AI_MATKEY_IOR with AI_MATKEY_REFRACTI.

---
 code/AssetLib/glTF2/glTF2Exporter.cpp | 2 +-
 code/AssetLib/glTF2/glTF2Importer.cpp | 2 +-
 include/assimp/material.h             | 6 ------
 3 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/code/AssetLib/glTF2/glTF2Exporter.cpp b/code/AssetLib/glTF2/glTF2Exporter.cpp
index 8327f8c54..572c61f2b 100644
--- a/code/AssetLib/glTF2/glTF2Exporter.cpp
+++ b/code/AssetLib/glTF2/glTF2Exporter.cpp
@@ -717,7 +717,7 @@ bool glTF2Exporter::GetMatVolume(const aiMaterial &mat, glTF2::MaterialVolume &v
 }
 
 bool glTF2Exporter::GetMatIOR(const aiMaterial &mat, glTF2::MaterialIOR &ior) {
-    return mat.Get(AI_MATKEY_IOR, ior.ior) == aiReturn_SUCCESS;
+    return mat.Get(AI_MATKEY_REFRACTI, ior.ior) == aiReturn_SUCCESS;
 }
 
 void glTF2Exporter::ExportMaterials() {
diff --git a/code/AssetLib/glTF2/glTF2Importer.cpp b/code/AssetLib/glTF2/glTF2Importer.cpp
index c7de2af4f..87f2604ca 100644
--- a/code/AssetLib/glTF2/glTF2Importer.cpp
+++ b/code/AssetLib/glTF2/glTF2Importer.cpp
@@ -355,7 +355,7 @@ static aiMaterial *ImportMaterial(std::vector<int> &embeddedTexIdxs, Asset &r, M
         if (mat.materialIOR.isPresent) {
             MaterialIOR &ior = mat.materialIOR.value;
 
-            aimat->AddProperty(&ior.ior, 1, AI_MATKEY_IOR);
+            aimat->AddProperty(&ior.ior, 1, AI_MATKEY_REFRACTI);
         }
 
         return aimat;
diff --git a/include/assimp/material.h b/include/assimp/material.h
index 5499bd916..4e55e4894 100644
--- a/include/assimp/material.h
+++ b/include/assimp/material.h
@@ -1041,12 +1041,6 @@ extern "C" {
 // The color that white light turns into due to absorption when reaching the attenuation distance.
 #define AI_MATKEY_VOLUME_ATTENUATION_COLOR "$mat.volume.attenuationColor", 0, 0
 
-// IOR
-// ------------
-// https://github.com/KhronosGroup/glTF/tree/main/extensions/2.0/Khronos/KHR_materials_ior
-// Index of Refraction.
-#define AI_MATKEY_IOR "$mat.ior", 0, 0
-
 // Emissive
 // --------
 #define AI_MATKEY_USE_EMISSIVE_MAP "$mat.useEmissiveMap", 0, 0

From 3b8126d26a9015f0d9557fa1e3377e14ec458c13 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?IOhannes=20m=20zm=C3=B6lnig?= <zmoelnig@iem.at>
Date: Tue, 5 Oct 2021 10:59:43 +0200
Subject: [PATCH 09/20] Fix spelling mistake

---
 code/AssetLib/3DS/3DSHelper.h                          |  2 +-
 code/AssetLib/AMF/AMFImporter_Postprocess.cpp          |  2 +-
 code/AssetLib/ASE/ASELoader.cpp                        |  2 +-
 code/AssetLib/Assbin/AssbinLoader.cpp                  |  2 +-
 code/AssetLib/Assxml/AssxmlFileWriter.cpp              |  2 +-
 code/AssetLib/BVH/BVHLoader.cpp                        |  2 +-
 code/AssetLib/BVH/BVHLoader.h                          |  2 +-
 code/AssetLib/Blender/BlenderDNA.h                     |  2 +-
 code/AssetLib/COB/COBLoader.cpp                        |  6 +++---
 code/AssetLib/FBX/FBXConverter.cpp                     |  2 +-
 code/AssetLib/FBX/FBXDocument.h                        |  2 +-
 code/AssetLib/FBX/FBXExporter.cpp                      |  4 ++--
 code/AssetLib/Irr/IRRLoader.cpp                        |  2 +-
 code/AssetLib/M3D/M3DExporter.cpp                      |  2 +-
 code/AssetLib/M3D/M3DImporter.cpp                      |  6 +++---
 code/AssetLib/M3D/m3d.h                                | 10 +++++-----
 code/AssetLib/MD3/MD3FileData.h                        |  2 +-
 code/AssetLib/MD5/MD5Parser.cpp                        |  2 +-
 code/AssetLib/MDL/MDLMaterialLoader.cpp                |  4 ++--
 code/AssetLib/MMD/MMDPmdParser.h                       |  4 ++--
 code/AssetLib/MMD/MMDVmdParser.h                       |  2 +-
 code/AssetLib/OFF/OFFLoader.cpp                        |  2 +-
 code/AssetLib/Obj/ObjFileData.h                        |  2 +-
 code/AssetLib/Ogre/OgreStructs.h                       |  2 +-
 code/AssetLib/OpenGEX/OpenGEXImporter.cpp              |  4 ++--
 code/AssetLib/Q3BSP/Q3BSPFileData.h                    |  2 +-
 code/AssetLib/SMD/SMDLoader.cpp                        |  2 +-
 code/AssetLib/X/XFileImporter.cpp                      |  2 +-
 code/AssetLib/X3D/X3DExporter.cpp                      |  6 +++---
 code/Common/BaseImporter.cpp                           |  2 +-
 code/Common/SGSpatialSort.cpp                          |  4 ++--
 code/Common/SpatialSort.cpp                            |  4 ++--
 code/PostProcessing/RemoveVCProcess.cpp                |  2 +-
 code/PostProcessing/ScaleProcess.cpp                   |  2 +-
 code/PostProcessing/SplitLargeMeshes.cpp               |  2 +-
 code/PostProcessing/TextureTransform.cpp               |  4 ++--
 doc/dox.h                                              | 10 +++++-----
 include/assimp/ByteSwapper.h                           |  2 +-
 include/assimp/LogAux.h                                |  2 +-
 include/assimp/MemoryIOWrapper.h                       |  2 +-
 include/assimp/StreamReader.h                          |  2 +-
 include/assimp/Vertex.h                                |  6 +++---
 include/assimp/cexport.h                               |  2 +-
 include/assimp/postprocess.h                           |  2 +-
 samples/SimpleAssimpViewX/MyDocument.h                 |  2 +-
 samples/SimpleOpenGL/Sample_SimpleOpenGL.c             |  2 +-
 .../SimpleTexturedDirectx11/main.cpp                   |  2 +-
 .../SimpleTexturedOpenGL/src/model_loading.cpp         |  2 +-
 test/unit/ImportExport/MDL/utMDLImporter_HL1_Nodes.cpp |  2 +-
 test/unit/utTriangulate.cpp                            |  2 +-
 tools/assimp_cmd/Info.cpp                              |  2 +-
 tools/assimp_view/Display.cpp                          |  4 ++--
 tools/assimp_view/Material.cpp                         |  2 +-
 tools/assimp_view/MessageProc.cpp                      |  4 ++--
 tools/assimp_view/SceneAnimator.h                      |  2 +-
 tools/assimp_view/assimp_view.cpp                      |  2 +-
 56 files changed, 81 insertions(+), 81 deletions(-)

diff --git a/code/AssetLib/3DS/3DSHelper.h b/code/AssetLib/3DS/3DSHelper.h
index 933795f65..3a5479de2 100644
--- a/code/AssetLib/3DS/3DSHelper.h
+++ b/code/AssetLib/3DS/3DSHelper.h
@@ -259,7 +259,7 @@ namespace Discreet3DS {
         // Specifies the file name of a texture
         CHUNK_MAPFILE = 0xA300,
 
-        // Specifies whether a materail requires two-sided rendering
+        // Specifies whether a material requires two-sided rendering
         CHUNK_MAT_TWO_SIDE = 0xA081,
         // ********************************************************************
 
diff --git a/code/AssetLib/AMF/AMFImporter_Postprocess.cpp b/code/AssetLib/AMF/AMFImporter_Postprocess.cpp
index d56d6681d..3674f3d25 100644
--- a/code/AssetLib/AMF/AMFImporter_Postprocess.cpp
+++ b/code/AssetLib/AMF/AMFImporter_Postprocess.cpp
@@ -690,7 +690,7 @@ void AMFImporter::Postprocess_BuildConstellation(AMFConstellation &pConstellatio
         if (ne->Type == AMFNodeElementBase::ENET_Metadata) continue;
         if (ne->Type != AMFNodeElementBase::ENET_Instance) throw DeadlyImportError("Only <instance> nodes can be in <constellation>.");
 
-        // create alias for conveniance
+        // create alias for convenience
         AMFInstance &als = *((AMFInstance *)ne);
         // find referenced object
         if (!Find_ConvertedNode(als.ObjectID, nodeArray, &found_node)) Throw_ID_NotFound(als.ObjectID);
diff --git a/code/AssetLib/ASE/ASELoader.cpp b/code/AssetLib/ASE/ASELoader.cpp
index 2be103321..fae441f57 100644
--- a/code/AssetLib/ASE/ASELoader.cpp
+++ b/code/AssetLib/ASE/ASELoader.cpp
@@ -681,7 +681,7 @@ void ASEImporter::BuildNodes(std::vector<BaseNode *> &nodes) {
         }
     }
 
-    // Are there ane orphaned nodes?
+    // Are there any orphaned nodes?
     if (!aiList.empty()) {
         std::vector<aiNode *> apcNodes;
         apcNodes.reserve(aiList.size() + pcScene->mRootNode->mNumChildren);
diff --git a/code/AssetLib/Assbin/AssbinLoader.cpp b/code/AssetLib/Assbin/AssbinLoader.cpp
index d94407e03..5ca4b3e11 100644
--- a/code/AssetLib/Assbin/AssbinLoader.cpp
+++ b/code/AssetLib/Assbin/AssbinLoader.cpp
@@ -406,7 +406,7 @@ void AssbinImporter::ReadBinaryMesh(IOStream *stream, aiMesh *mesh) {
             f.mIndices = new unsigned int[f.mNumIndices];
 
             for (unsigned int a = 0; a < f.mNumIndices; ++a) {
-                // Check if unsigned  short ( 16 bit  ) are big enought for the indices
+                // Check if unsigned  short ( 16 bit  ) are big enough for the indices
                 if (fitsIntoUI16(mesh->mNumVertices)) {
                     f.mIndices[a] = Read<uint16_t>(stream);
                 } else {
diff --git a/code/AssetLib/Assxml/AssxmlFileWriter.cpp b/code/AssetLib/Assxml/AssxmlFileWriter.cpp
index 24fda5955..d16580a2e 100644
--- a/code/AssetLib/Assxml/AssxmlFileWriter.cpp
+++ b/code/AssetLib/Assxml/AssxmlFileWriter.cpp
@@ -168,7 +168,7 @@ static void WriteNode(const aiNode *node, IOStream *io, unsigned int depth) {
 }
 
 // -----------------------------------------------------------------------------------
-// Some chuncks of text will need to be encoded for XML
+// Some chunks of text will need to be encoded for XML
 // http://stackoverflow.com/questions/5665231/most-efficient-way-to-escape-xml-html-in-c-string#5665377
 static std::string encodeXML(const std::string &data) {
     std::string buffer;
diff --git a/code/AssetLib/BVH/BVHLoader.cpp b/code/AssetLib/BVH/BVHLoader.cpp
index 6d9069021..6dc824e2f 100644
--- a/code/AssetLib/BVH/BVHLoader.cpp
+++ b/code/AssetLib/BVH/BVHLoader.cpp
@@ -178,7 +178,7 @@ void BVHLoader::ReadHierarchy(aiScene *pScene) {
 }
 
 // ------------------------------------------------------------------------------------------------
-// Reads a node and recursively its childs and returns the created node;
+// Reads a node and recursively its children and returns the created node;
 aiNode *BVHLoader::ReadNode() {
     // first token is name
     std::string nodeName = GetNextToken();
diff --git a/code/AssetLib/BVH/BVHLoader.h b/code/AssetLib/BVH/BVHLoader.h
index a66a20275..70511483d 100644
--- a/code/AssetLib/BVH/BVHLoader.h
+++ b/code/AssetLib/BVH/BVHLoader.h
@@ -112,7 +112,7 @@ protected:
     /** Reads the hierarchy */
     void ReadHierarchy(aiScene *pScene);
 
-    /** Reads a node and recursively its childs and returns the created node. */
+    /** Reads a node and recursively its children and returns the created node. */
     aiNode *ReadNode();
 
     /** Reads an end node and returns the created node. */
diff --git a/code/AssetLib/Blender/BlenderDNA.h b/code/AssetLib/Blender/BlenderDNA.h
index f566554b8..871ee71a1 100644
--- a/code/AssetLib/Blender/BlenderDNA.h
+++ b/code/AssetLib/Blender/BlenderDNA.h
@@ -476,7 +476,7 @@ public:
      *  in BlenderScene.cpp and is machine-generated.
      *  Converters are used to quickly handle objects whose
      *  exact data type is a runtime-property and not yet
-     *  known at compile time (consier Object::data).*/
+     *  known at compile time (consider Object::data).*/
     void RegisterConverters();
 
     // --------------------------------------------------------
diff --git a/code/AssetLib/COB/COBLoader.cpp b/code/AssetLib/COB/COBLoader.cpp
index 88aa88773..647f49052 100644
--- a/code/AssetLib/COB/COBLoader.cpp
+++ b/code/AssetLib/COB/COBLoader.cpp
@@ -586,7 +586,7 @@ void COBImporter::ReadUnit_Ascii(Scene &out, LineSplitter &splitter, const Chunk
         return;
     }
 
-    // parent chunks preceede their childs, so we should have the
+    // parent chunks preceede their children, so we should have the
     // corresponding chunk already.
     for (std::shared_ptr<Node> &nd : out.nodes) {
         if (nd->id == nfo.parent_id) {
@@ -668,7 +668,7 @@ void COBImporter::ReadCame_Ascii(Scene &out, LineSplitter &splitter, const Chunk
 
     ReadBasicNodeInfo_Ascii(msh, ++splitter, nfo);
 
-    // skip the next line, we don't know this differenciation between a
+    // skip the next line, we don't know this differentiation between a
     // standard camera and a panoramic camera.
     ++splitter;
 }
@@ -1169,7 +1169,7 @@ void COBImporter::ReadUnit_Binary(COB::Scene &out, StreamReaderLE &reader, const
 
     const chunk_guard cn(nfo, reader);
 
-    // parent chunks preceede their childs, so we should have the
+    // parent chunks preceede their children, so we should have the
     // corresponding chunk already.
     for (std::shared_ptr<Node> &nd : out.nodes) {
         if (nd->id == nfo.parent_id) {
diff --git a/code/AssetLib/FBX/FBXConverter.cpp b/code/AssetLib/FBX/FBXConverter.cpp
index fa7ee3986..c025e8954 100644
--- a/code/AssetLib/FBX/FBXConverter.cpp
+++ b/code/AssetLib/FBX/FBXConverter.cpp
@@ -1595,7 +1595,7 @@ void FBXConverter::ConvertCluster(std::vector<aiBone *> &local_mesh_bones, const
         bone_map.insert(std::pair<const std::string, aiBone *>(deformer_name, bone));
     }
 
-    ASSIMP_LOG_DEBUG("bone research: Indicies size: ", out_indices.size());
+    ASSIMP_LOG_DEBUG("bone research: Indices size: ", out_indices.size());
 
     // lookup must be populated in case something goes wrong
     // this also allocates bones to mesh instance outside
diff --git a/code/AssetLib/FBX/FBXDocument.h b/code/AssetLib/FBX/FBXDocument.h
index 1ee526368..eeb173cd0 100644
--- a/code/AssetLib/FBX/FBXDocument.h
+++ b/code/AssetLib/FBX/FBXDocument.h
@@ -693,7 +693,7 @@ private:
 typedef std::vector<int64_t> KeyTimeList;
 typedef std::vector<float> KeyValueList;
 
-/** Represents a FBX animation curve (i.e. a 1-dimensional set of keyframes and values therefor) */
+/** Represents a FBX animation curve (i.e. a 1-dimensional set of keyframes and values therefore) */
 class AnimationCurve : public Object {
 public:
     AnimationCurve(uint64_t id, const Element& element, const std::string& name, const Document& doc);
diff --git a/code/AssetLib/FBX/FBXExporter.cpp b/code/AssetLib/FBX/FBXExporter.cpp
index f4a3017d8..66e14c75c 100644
--- a/code/AssetLib/FBX/FBXExporter.cpp
+++ b/code/AssetLib/FBX/FBXExporter.cpp
@@ -1709,7 +1709,7 @@ void FBXExporter::WriteObjects ()
             //p.AddP70string("UVSet", ""); // TODO: how should this work?
             p.AddP70bool("UseMaterial", 1);
             tnode.AddChild(p);
-            // can't easily detrmine which texture path will be correct,
+            // can't easily determine which texture path will be correct,
             // so just store what we have in every field.
             // these being incorrect is a common problem with FBX anyway.
             tnode.AddChild("FileName", texture_path);
@@ -1915,7 +1915,7 @@ void FBXExporter::WriteObjects ()
             // mark all parent nodes as skeleton as well,
             // up until we find the root node,
             // or else the node containing the mesh,
-            // or else the parent of a node containig the mesh.
+            // or else the parent of a node containing the mesh.
             for (
                 const aiNode* parent = n->mParent;
                 parent && parent != mScene->mRootNode;
diff --git a/code/AssetLib/Irr/IRRLoader.cpp b/code/AssetLib/Irr/IRRLoader.cpp
index c741159f6..b68671e0d 100644
--- a/code/AssetLib/Irr/IRRLoader.cpp
+++ b/code/AssetLib/Irr/IRRLoader.cpp
@@ -132,7 +132,7 @@ void IRRImporter::SetupProperties(const Importer *pImp) {
 }
 
 // ------------------------------------------------------------------------------------------------
-// Build a mesh tha consists of a single squad (a side of a skybox)
+// Build a mesh that consists of a single squad (a side of a skybox)
 aiMesh *IRRImporter::BuildSingleQuadMesh(const SkyboxVertex &v1,
 		const SkyboxVertex &v2,
 		const SkyboxVertex &v3,
diff --git a/code/AssetLib/M3D/M3DExporter.cpp b/code/AssetLib/M3D/M3DExporter.cpp
index bcac1d98a..fdcf9c321 100644
--- a/code/AssetLib/M3D/M3DExporter.cpp
+++ b/code/AssetLib/M3D/M3DExporter.cpp
@@ -76,7 +76,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  * Currently supports static meshes, vertex colors, materials, textures
  *
  * For animation, it would require the following conversions:
- *  - aiNode (bones) -> m3d_t.bone (with parent id, position vector and oriantation quaternion)
+ *  - aiNode (bones) -> m3d_t.bone (with parent id, position vector and orientation quaternion)
  *  - aiMesh.aiBone -> m3d_t.skin (per vertex, with bone id, weight pairs)
  *  - aiAnimation -> m3d_action (frame with timestamp and list of bone id, position, orientation
  *      triplets, instead of per bone timestamp + lists)
diff --git a/code/AssetLib/M3D/M3DImporter.cpp b/code/AssetLib/M3D/M3DImporter.cpp
index efa1d5475..d87944456 100644
--- a/code/AssetLib/M3D/M3DImporter.cpp
+++ b/code/AssetLib/M3D/M3DImporter.cpp
@@ -296,7 +296,7 @@ void M3DImporter::importMaterials(const M3DWrapper &m3d) {
             }
             // texture map properties
             if (m->prop[j].type >= 128 && aiTxProps[k].pKey &&
-                    // extra check, should never happen, do we have the refered texture?
+                    // extra check, should never happen, do we have the referred texture?
                     m->prop[j].value.textureid < m3d->numtexture &&
                     m3d->texture[m->prop[j].value.textureid].name) {
                 name.Set(std::string(std::string(m3d->texture[m->prop[j].value.textureid].name) + ".png"));
@@ -474,7 +474,7 @@ void M3DImporter::importMeshes(const M3DWrapper &m3d) {
     mScene->mMeshes = new aiMesh *[mScene->mNumMeshes];
     std::copy(meshes->begin(), meshes->end(), mScene->mMeshes);
 
-    // create mesh indeces in root node
+    // create mesh indices in root node
     mScene->mRootNode->mNumMeshes = static_cast<unsigned int>(meshes->size());
     mScene->mRootNode->mMeshes = new unsigned int[meshes->size()];
     for (i = 0; i < meshes->size(); i++) {
@@ -688,7 +688,7 @@ void M3DImporter::calculateOffsetMatrix(aiNode *pNode, aiMatrix4x4 *m) {
 
 // ------------------------------------------------------------------------------------------------
 // because M3D has a global mesh, global vertex ids and stores materialid on the face, we need
-// temporary lists to collect data for an aiMesh, which requires local arrays and local indeces
+// temporary lists to collect data for an aiMesh, which requires local arrays and local indices
 // this function fills up an aiMesh with those temporary lists
 void M3DImporter::populateMesh(const M3DWrapper &m3d, aiMesh *pMesh, std::vector<aiFace> *faces, std::vector<aiVector3D> *vertices,
         std::vector<aiVector3D> *normals, std::vector<aiVector3D> *texcoords, std::vector<aiColor4D> *colors,
diff --git a/code/AssetLib/M3D/m3d.h b/code/AssetLib/M3D/m3d.h
index 3adcd5bef..b148c11d7 100644
--- a/code/AssetLib/M3D/m3d.h
+++ b/code/AssetLib/M3D/m3d.h
@@ -59,7 +59,7 @@ extern "C" {
 #ifndef M3D_DOUBLE
 typedef float M3D_FLOAT;
 #ifndef M3D_EPSILON
-/* carefully choosen for IEEE 754 don't change */
+/* carefully chosen for IEEE 754 don't change */
 #define M3D_EPSILON ((M3D_FLOAT)1e-7)
 #endif
 #else
@@ -121,7 +121,7 @@ typedef uint16_t M3D_INDEX;
  *      TMAP texture map chunk (optional)
  *      VRTS vertex data chunk (optional if it's a material library)
  *      BONE bind-pose skeleton, bone hierarchy chunk (optional)
- *          n x m3db_t contains propably more, but at least one bone
+ *          n x m3db_t contains probably more, but at least one bone
  *          n x m3ds_t skin group records
  *      MTRL* material chunk(s), can be more (optional)
  *          n x m3dp_t each material contains propapbly more, but at least one property
@@ -1109,7 +1109,7 @@ void _m3d_inv(M3D_FLOAT *m) {
     r[15] = det * (m[0] * (m[5] * m[10] - m[6] * m[9]) + m[1] * (m[6] * m[8] - m[4] * m[10]) + m[2] * (m[4] * m[9] - m[5] * m[8]));
     memcpy(m, &r, sizeof(r));
 }
-/* compose a coloumn major 4 x 4 matrix from vec3 position and vec4 orientation/rotation quaternion */
+/* compose a column major 4 x 4 matrix from vec3 position and vec4 orientation/rotation quaternion */
 void _m3d_mat(M3D_FLOAT *r, m3dv_t *p, m3dv_t *q) {
     if (q->x == (M3D_FLOAT)0.0 && q->y == (M3D_FLOAT)0.0 && q->z >= (M3D_FLOAT)0.7071065 && q->z <= (M3D_FLOAT)0.7071075 &&
             q->w == (M3D_FLOAT)0.0) {
@@ -4033,7 +4033,7 @@ unsigned char *m3d_save(m3d_t *model, int quality, int flags, unsigned int *size
         out[len] = 0;
     } else
     {
-        /* stricly only use LF (newline) in binary */
+        /* strictly only use LF (newline) in binary */
         sd = _m3d_safestr(model->desc, 3);
         if (!sd) goto memerr;
         /* header */
@@ -4608,7 +4608,7 @@ unsigned char *m3d_save(m3d_t *model, int quality, int flags, unsigned int *size
                 h = (m3dhdr_t *)z;
             }
         }
-        /* add file header at the begining */
+        /* add file header at the beginning */
         len += 8;
         out = (unsigned char *)M3D_MALLOC(len);
         if (!out) goto memerr;
diff --git a/code/AssetLib/MD3/MD3FileData.h b/code/AssetLib/MD3/MD3FileData.h
index a44f688f9..62b5fb706 100644
--- a/code/AssetLib/MD3/MD3FileData.h
+++ b/code/AssetLib/MD3/MD3FileData.h
@@ -271,7 +271,7 @@ inline void LatLngNormalToVec3(uint16_t p_iNormal, ai_real* p_afOut)
 
 
 // -------------------------------------------------------------------------------
-/** @brief Pack a Q3 normal into 16bit latitute/longitude representation
+/** @brief Pack a Q3 normal into 16bit latitude/longitude representation
  *  @param p_vIn Input vector
  *  @param p_iOut Output normal
  *
diff --git a/code/AssetLib/MD5/MD5Parser.cpp b/code/AssetLib/MD5/MD5Parser.cpp
index a69275507..802c9becd 100644
--- a/code/AssetLib/MD5/MD5Parser.cpp
+++ b/code/AssetLib/MD5/MD5Parser.cpp
@@ -59,7 +59,7 @@ using namespace Assimp;
 using namespace Assimp::MD5;
 
 // ------------------------------------------------------------------------------------------------
-// Parse the segment structure fo a MD5 file
+// Parse the segment structure for an MD5 file
 MD5Parser::MD5Parser(char *_buffer, unsigned int _fileSize) {
     ai_assert(nullptr != _buffer);
     ai_assert(0 != _fileSize);
diff --git a/code/AssetLib/MDL/MDLMaterialLoader.cpp b/code/AssetLib/MDL/MDLMaterialLoader.cpp
index fd287430b..f44896819 100644
--- a/code/AssetLib/MDL/MDLMaterialLoader.cpp
+++ b/code/AssetLib/MDL/MDLMaterialLoader.cpp
@@ -387,7 +387,7 @@ void MDLImporter::CreateTexture_3DGS_MDL5(const unsigned char *szData,
     // this should not occur - at least the docs say it shouldn't.
     // however, one can easily try out what MED does if you have
     // a model with a DDS texture and export it to MDL5 ...
-    // yeah, it embedds the DDS file.
+    // yeah, it embeds the DDS file.
     if (6 == iType) {
         // this is a compressed texture in DDS format
         *piSkip = pcNew->mWidth;
@@ -524,7 +524,7 @@ void MDLImporter::ParseSkinLump_3DGS_MDL7(
     }
 
     // sometimes there are MDL7 files which have a monochrome
-    // texture instead of material colors ... posssible they have
+    // texture instead of material colors ... possible they have
     // been converted to MDL7 from other formats, such as MDL5
     aiColor4D clrTexture;
     if (pcNew)
diff --git a/code/AssetLib/MMD/MMDPmdParser.h b/code/AssetLib/MMD/MMDPmdParser.h
index be8dad5c3..f9f555c6a 100644
--- a/code/AssetLib/MMD/MMDPmdParser.h
+++ b/code/AssetLib/MMD/MMDPmdParser.h
@@ -195,7 +195,7 @@ namespace pmd
 	public:
 		uint16_t ik_bone_index;
 		uint16_t target_bone_index;
-		uint16_t interations;
+		uint16_t iterations;
 		float angle_limit;
 		std::vector<uint16_t> ik_child_bone_index;
 
@@ -205,7 +205,7 @@ namespace pmd
 			stream->read((char *) &target_bone_index, sizeof(uint16_t));
 			uint8_t ik_chain_length;
 			stream->read((char*) &ik_chain_length, sizeof(uint8_t));
-			stream->read((char *) &interations, sizeof(uint16_t));
+			stream->read((char *) &iterations, sizeof(uint16_t));
 			stream->read((char *) &angle_limit, sizeof(float));
 			ik_child_bone_index.resize(ik_chain_length);
 			for (int i = 0; i < ik_chain_length; i++)
diff --git a/code/AssetLib/MMD/MMDVmdParser.h b/code/AssetLib/MMD/MMDVmdParser.h
index 53f1922b5..0ce24a48f 100644
--- a/code/AssetLib/MMD/MMDVmdParser.h
+++ b/code/AssetLib/MMD/MMDVmdParser.h
@@ -358,7 +358,7 @@ namespace vmd
 				light_frames[i].Write(stream);
 			}
 
-			// self shadow datas
+			// self shadow data
 			const int self_shadow_num = 0;
 			stream->write(reinterpret_cast<const char*>(&self_shadow_num), sizeof(int));
 
diff --git a/code/AssetLib/OFF/OFFLoader.cpp b/code/AssetLib/OFF/OFFLoader.cpp
index 8509d0c4d..644579bce 100644
--- a/code/AssetLib/OFF/OFFLoader.cpp
+++ b/code/AssetLib/OFF/OFFLoader.cpp
@@ -233,7 +233,7 @@ void OFFImporter::InternReadFile( const std::string& pFile, aiScene* pScene, IOS
 	    sz = fast_atoreal_move<ai_real>(sz, *vec[dim]);
 	}
 
-	// if has homogenous coordinate, divide others by this one
+	// if has homogeneous coordinate, divide others by this one
 	if (hasHomogenous) {
 	    SkipSpaces(&sz);
 	    ai_real w = 1.;
diff --git a/code/AssetLib/Obj/ObjFileData.h b/code/AssetLib/Obj/ObjFileData.h
index 92fe3a261..b14250020 100644
--- a/code/AssetLib/Obj/ObjFileData.h
+++ b/code/AssetLib/Obj/ObjFileData.h
@@ -233,7 +233,7 @@ struct Mesh {
 
 // ------------------------------------------------------------------------------------------------
 //! \struct Model
-//! \brief  Data structure to store all obj-specific model datas
+//! \brief  Data structure to store all obj-specific model data
 // ------------------------------------------------------------------------------------------------
 struct Model {
     using GroupMap = std::map<std::string, std::vector<unsigned int> *>;
diff --git a/code/AssetLib/Ogre/OgreStructs.h b/code/AssetLib/Ogre/OgreStructs.h
index c34546a74..1d43b09e9 100644
--- a/code/AssetLib/Ogre/OgreStructs.h
+++ b/code/AssetLib/Ogre/OgreStructs.h
@@ -555,7 +555,7 @@ public:
         should be 0 after this reset. */
     void Reset();
 
-    /// Covert to Assimp mesh.
+    /// Convert to Assimp mesh.
     aiMesh *ConvertToAssimpMesh(Mesh *parent);
 
     /// Vertex data.
diff --git a/code/AssetLib/OpenGEX/OpenGEXImporter.cpp b/code/AssetLib/OpenGEX/OpenGEXImporter.cpp
index bbf689b60..94cf47e73 100644
--- a/code/AssetLib/OpenGEX/OpenGEXImporter.cpp
+++ b/code/AssetLib/OpenGEX/OpenGEXImporter.cpp
@@ -351,8 +351,8 @@ void OpenGEXImporter::handleNodes(DDLNode *node, aiScene *pScene) {
         return;
     }
 
-    DDLNode::DllNodeList childs = node->getChildNodeList();
-    for (DDLNode::DllNodeList::iterator it = childs.begin(); it != childs.end(); ++it) {
+    DDLNode::DllNodeList children = node->getChildNodeList();
+    for (DDLNode::DllNodeList::iterator it = children.begin(); it != children.end(); ++it) {
         Grammar::TokenType tokenType(Grammar::matchTokenType((*it)->getType().c_str()));
         switch (tokenType) {
         case Grammar::MetricToken:
diff --git a/code/AssetLib/Q3BSP/Q3BSPFileData.h b/code/AssetLib/Q3BSP/Q3BSPFileData.h
index a121cdbcd..c288af2fc 100644
--- a/code/AssetLib/Q3BSP/Q3BSPFileData.h
+++ b/code/AssetLib/Q3BSP/Q3BSPFileData.h
@@ -95,7 +95,7 @@ struct sQ3BSPVertex {
     vec3f vPosition;    ///< Position of vertex
     vec2f vTexCoord;    ///< (u,v) Texturecoordinate of detailtexture
     vec2f vLightmap;    ///< (u,v) Texturecoordinate of lightmap
-    vec3f vNormal;      ///< vertex normale
+    vec3f vNormal;      ///< vertex normal
     unsigned char bColor[ 4 ];          ///< Color in RGBA
 };
 
diff --git a/code/AssetLib/SMD/SMDLoader.cpp b/code/AssetLib/SMD/SMDLoader.cpp
index 90f0b7697..8d9c745b1 100644
--- a/code/AssetLib/SMD/SMDLoader.cpp
+++ b/code/AssetLib/SMD/SMDLoader.cpp
@@ -868,7 +868,7 @@ void SMDImporter::ParseNodeInfo(const char* szCurrent, const char** szCurrentOut
 
     bool bQuota = true;
     if ('\"' != *szCurrent) {
-        LogWarning("Bone name is expcted to be enclosed in "
+        LogWarning("Bone name is expected to be enclosed in "
             "double quotation marks. ");
         bQuota = false;
     } else {
diff --git a/code/AssetLib/X/XFileImporter.cpp b/code/AssetLib/X/XFileImporter.cpp
index 111bd0886..8a3047915 100644
--- a/code/AssetLib/X/XFileImporter.cpp
+++ b/code/AssetLib/X/XFileImporter.cpp
@@ -219,7 +219,7 @@ aiNode* XFileImporter::CreateNodes( aiScene* pScene, aiNode* pParent, const XFil
     // convert meshes from the source node
     CreateMeshes( pScene, node, pNode->mMeshes);
 
-    // handle childs
+    // handle children
     if( !pNode->mChildren.empty() ) {
         node->mNumChildren = (unsigned int)pNode->mChildren.size();
         node->mChildren = new aiNode* [node->mNumChildren];
diff --git a/code/AssetLib/X3D/X3DExporter.cpp b/code/AssetLib/X3D/X3DExporter.cpp
index 7404bc760..b3278a528 100644
--- a/code/AssetLib/X3D/X3DExporter.cpp
+++ b/code/AssetLib/X3D/X3DExporter.cpp
@@ -279,7 +279,7 @@ void X3DExporter::Export_Mesh(const size_t pIdxMesh, const size_t pTabLevel) {
     const char *NodeName_Shape = "Shape";
 
     list<SAttribute> attr_list;
-    aiMesh &mesh = *mScene->mMeshes[pIdxMesh]; // create alias for conveniance.
+    aiMesh &mesh = *mScene->mMeshes[pIdxMesh]; // create alias for convenience.
 
     // Check if mesh already defined early.
     if (mDEF_Map_Mesh.find(pIdxMesh) != mDEF_Map_Mesh.end()) {
@@ -375,7 +375,7 @@ void X3DExporter::Export_Material(const size_t pIdxMaterial, const size_t pTabLe
     const char *NodeName_A = "Appearance";
 
     list<SAttribute> attr_list;
-    aiMaterial &material = *mScene->mMaterials[pIdxMaterial]; // create alias for conveniance.
+    aiMaterial &material = *mScene->mMaterials[pIdxMaterial]; // create alias for convenience.
 
     // Check if material already defined early.
     if (mDEF_Map_Material.find(pIdxMaterial) != mDEF_Map_Material.end()) {
@@ -586,7 +586,7 @@ bool X3DExporter::CheckAndExport_Light(const aiNode &pNode, const size_t pTabLev
     if (!found) return false;
 
     // Light source is found.
-    const aiLight &light = *mScene->mLights[idx_light]; // Alias for conveniance.
+    const aiLight &light = *mScene->mLights[idx_light]; // Alias for convenience.
 
     aiMatrix4x4 trafo_mat = Matrix_GlobalToCurrent(pNode).Inverse();
 
diff --git a/code/Common/BaseImporter.cpp b/code/Common/BaseImporter.cpp
index fa6cac938..d7e24afab 100644
--- a/code/Common/BaseImporter.cpp
+++ b/code/Common/BaseImporter.cpp
@@ -207,7 +207,7 @@ void BaseImporter::GetExtensionList(std::set<std::string> &extensions) {
             if (!r) {
                 continue;
             }
-            // We need to make sure that we didn't accidentially identify the end of another token as our token,
+            // We need to make sure that we didn't accidentally identify the end of another token as our token,
             // e.g. in a previous version the "gltf " present in some gltf files was detected as "f "
             if (noAlphaBeforeTokens && (r != buffer && isalpha(static_cast<unsigned char>(r[-1])))) {
                 continue;
diff --git a/code/Common/SGSpatialSort.cpp b/code/Common/SGSpatialSort.cpp
index 0475bce6e..78b869260 100644
--- a/code/Common/SGSpatialSort.cpp
+++ b/code/Common/SGSpatialSort.cpp
@@ -52,7 +52,7 @@ using namespace Assimp;
 // ------------------------------------------------------------------------------------------------
 SGSpatialSort::SGSpatialSort()
 {
-    // define the reference plane. We choose some arbitrary vector away from all basic axises
+    // define the reference plane. We choose some arbitrary vector away from all basic axes
     // in the hope that no model spreads all its vertices along this plane.
     mPlaneNormal.Set( 0.8523f, 0.34321f, 0.5736f);
     mPlaneNormal.Normalize();
@@ -121,7 +121,7 @@ void SGSpatialSort::FindPositions( const aiVector3D& pPosition,
         index++;
 
     // Mow start iterating from there until the first position lays outside of the distance range.
-    // Add all positions inside the distance range within the given radius to the result aray
+    // Add all positions inside the distance range within the given radius to the result array
 
     float squareEpsilon = pRadius * pRadius;
     std::vector<Entry>::const_iterator it  = mPositions.begin() + index;
diff --git a/code/Common/SpatialSort.cpp b/code/Common/SpatialSort.cpp
index 66ca2ffc6..2bd848164 100644
--- a/code/Common/SpatialSort.cpp
+++ b/code/Common/SpatialSort.cpp
@@ -55,7 +55,7 @@ const aiVector3D PlaneInit(0.8523f, 0.34321f, 0.5736f);
 
 // ------------------------------------------------------------------------------------------------
 // Constructs a spatially sorted representation from the given position array.
-// define the reference plane. We choose some arbitrary vector away from all basic axises
+// define the reference plane. We choose some arbitrary vector away from all basic axes
 // in the hope that no model spreads all its vertices along this plane.
 SpatialSort::SpatialSort(const aiVector3D *pPositions, unsigned int pNumPositions, unsigned int pElementOffset) :
         mPlaneNormal(PlaneInit) {
@@ -148,7 +148,7 @@ void SpatialSort::FindPositions(const aiVector3D &pPosition,
         index++;
 
     // Mow start iterating from there until the first position lays outside of the distance range.
-    // Add all positions inside the distance range within the given radius to the result aray
+    // Add all positions inside the distance range within the given radius to the result array
     std::vector<Entry>::const_iterator it = mPositions.begin() + index;
     const ai_real pSquared = pRadius * pRadius;
     while (it->mDistance < maxDist) {
diff --git a/code/PostProcessing/RemoveVCProcess.cpp b/code/PostProcessing/RemoveVCProcess.cpp
index 43be09196..9ee1da15c 100644
--- a/code/PostProcessing/RemoveVCProcess.cpp
+++ b/code/PostProcessing/RemoveVCProcess.cpp
@@ -67,7 +67,7 @@ bool RemoveVCProcess::IsActive(unsigned int pFlags) const {
 }
 
 // ------------------------------------------------------------------------------------------------
-// Small helper function to delete all elements in a T** aray using delete
+// Small helper function to delete all elements in a T** array using delete
 template <typename T>
 inline void ArrayDelete(T **&in, unsigned int &num) {
     for (unsigned int i = 0; i < num; ++i)
diff --git a/code/PostProcessing/ScaleProcess.cpp b/code/PostProcessing/ScaleProcess.cpp
index 63dd0443d..8fb3dc903 100644
--- a/code/PostProcessing/ScaleProcess.cpp
+++ b/code/PostProcessing/ScaleProcess.cpp
@@ -118,7 +118,7 @@ void ScaleProcess::Execute( aiScene* pScene ) {
     {
         aiMesh *mesh = pScene->mMeshes[meshID];
 
-        // Reconstruct mesh vertexes to the new unit system
+        // Reconstruct mesh vertices to the new unit system
         for( unsigned int vertexID = 0; vertexID < mesh->mNumVertices; vertexID++)
         {
             aiVector3D& vertex = mesh->mVertices[vertexID];
diff --git a/code/PostProcessing/SplitLargeMeshes.cpp b/code/PostProcessing/SplitLargeMeshes.cpp
index cb614edaa..b601a1331 100644
--- a/code/PostProcessing/SplitLargeMeshes.cpp
+++ b/code/PostProcessing/SplitLargeMeshes.cpp
@@ -129,7 +129,7 @@ void SplitLargeMeshesProcess_Triangle::UpdateNode(aiNode* pcNode,
         pcNode->mMeshes[b] = aiEntries[b];
     }
 
-    // recusively update all other nodes
+    // recursively update all other nodes
     for (unsigned int i = 0; i < pcNode->mNumChildren;++i) {
         UpdateNode ( pcNode->mChildren[i], avList );
     }
diff --git a/code/PostProcessing/TextureTransform.cpp b/code/PostProcessing/TextureTransform.cpp
index 74b00d92c..1cb7f293e 100644
--- a/code/PostProcessing/TextureTransform.cpp
+++ b/code/PostProcessing/TextureTransform.cpp
@@ -178,7 +178,7 @@ void TextureTransformStep::PreProcessUVTransform(STransformVecInfo& info)
         }
         else if (aiTextureMapMode_Clamp == info.mapV || aiTextureMapMode_Decal == info.mapV)    {
             // Clamp - translations beyond 1,1 are senseless
-            ::ai_snprintf(szTemp,512,"[c] UV V offset %f canbe clamped to 1.0f",info.mTranslation.y);
+            ::ai_snprintf(szTemp,512,"[c] UV V offset %f can be clamped to 1.0f",info.mTranslation.y);
 
             out = 1.f;
         }
@@ -539,7 +539,7 @@ void TextureTransformStep::Execute( aiScene* pScene)
                 m5.a3 += trl.x; m5.b3 += trl.y;
                 matrix = m2 * m4 * matrix * m3 * m5;
 
-                for (src = dest; src != end; ++src) { /* manual homogenious divide */
+                for (src = dest; src != end; ++src) { /* manual homogeneous divide */
                     src->z = 1.f;
                     *src = matrix * *src;
                     src->x /= src->z;
diff --git a/doc/dox.h b/doc/dox.h
index 409e775d4..1d5f59aa4 100644
--- a/doc/dox.h
+++ b/doc/dox.h
@@ -85,7 +85,7 @@ as long as you retain the license information and take own responsibility for wh
 the LICENSE file.
 
 You can find test models for almost all formats in the <assimp_root>/test/models directory. Beware, they're *free*,
-but not all of them are *open-source*. If there's an accompagning '<file>\source.txt' file don't forget to read it.
+but not all of them are *open-source*. If there's an accompanying '<file>\source.txt' file don't forget to read it.
 
 @section main_install Installation
 
@@ -687,7 +687,7 @@ There are two cases:
    format such as DDS or PNG. The term "compressed" does not mean that the texture data must
    actually be compressed, however the texture was found in the model file as if it was stored in a
    separate file on the harddisk. Appropriate decoders (such as libjpeg, libpng, D3DX, DevIL) are
-   required to load theses textures.  aiTexture::mWidth specifies the size of the texture data in
+   required to load these textures.  aiTexture::mWidth specifies the size of the texture data in
    bytes, aiTexture::pcData is a pointer to the raw image data and aiTexture::achFormatHint is
    either zeroed or contains the most common file extension of the embedded texture's format. This
    value is only set if assimp is able to determine the file format.
@@ -1181,7 +1181,7 @@ You can get assigned shader sources by using the following material keys:
 <li>AI_MATKEY_SHADER_VERTEX</li> Assigned vertex shader code stored as a string.
 <li>AI_MATKEY_SHADER_FRAGMENT</li> Assigned fragment shader code stored as a string.
 <li>AI_MATKEY_SHADER_GEO</li> Assigned geometry shader code stored as a string.
-<li>AI_MATKEY_SHADER_TESSELATION</li> Assigned tesselation shader code stored as a string.
+<li>AI_MATKEY_SHADER_TESSELATION</li> Assigned tessellation shader code stored as a string.
 <li>AI_MATKEY_SHADER_PRIMITIVE</li> Assigned primitive shader code stored as a string.
 <li>AI_MATKEY_SHADER_COMPUTE</li> Assigned compute shader code stored as a string.
 
@@ -1359,7 +1359,7 @@ When filing bugs on the Blender loader, always give the Blender version (or, eve
 This section contains implementation notes on the IFC-STEP importer.
 @subsection ifc_overview Overview
 
-The library provides a partial implementation of the IFC2x3 industry standard for automatized exchange of CAE/architectural
+The library provides a partial implementation of the IFC2x3 industry standard for automated exchange of CAE/architectural
 data sets. See http://en.wikipedia.org/wiki/Industry_Foundation_Classes for more information on the format. We aim
 at getting as much 3D data out of the files as possible.
 
@@ -1503,7 +1503,7 @@ like Windows and Linux ( 32 bit and 64 bit ).
 </li>
 <li>
 Provide some _free_ test models in <tt>&lt;root&gt;/test/models/&lt;FormatName&gt;/</tt> and credit their authors.
-Test files for a file format shouldn't be too large (<i>~500 KiB in total</i>), and not too repetive. Try to cover all format features with test data.
+Test files for a file format shouldn't be too large (<i>~500 KiB in total</i>), and not too repetitive. Try to cover all format features with test data.
 </li>
 <li>
 Done! Please, share your loader that everyone can profit from it!
diff --git a/include/assimp/ByteSwapper.h b/include/assimp/ByteSwapper.h
index 9e1eea10f..94df04b7f 100644
--- a/include/assimp/ByteSwapper.h
+++ b/include/assimp/ByteSwapper.h
@@ -40,7 +40,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 ----------------------------------------------------------------------
 */
 
-/** @file Helper class tp perform various byte oder swappings
+/** @file Helper class tp perform various byte order swappings
    (e.g. little to big endian) */
 #pragma once
 #ifndef AI_BYTESWAPPER_H_INC
diff --git a/include/assimp/LogAux.h b/include/assimp/LogAux.h
index 70e07790e..01a7d6375 100644
--- a/include/assimp/LogAux.h
+++ b/include/assimp/LogAux.h
@@ -56,7 +56,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 namespace Assimp {
 
-/// @brief Logger class, which will exten the class by log-functions.
+/// @brief Logger class, which will extend the class by log-functions.
 /// @tparam TDeriving 
 template<class TDeriving>
 class LogFunctions {
diff --git a/include/assimp/MemoryIOWrapper.h b/include/assimp/MemoryIOWrapper.h
index 24f6a85d1..0e509d997 100644
--- a/include/assimp/MemoryIOWrapper.h
+++ b/include/assimp/MemoryIOWrapper.h
@@ -41,7 +41,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
 /** @file MemoryIOWrapper.h
- *  Handy IOStream/IOSystem implemetation to read directly from a memory buffer */
+ *  Handy IOStream/IOSystem implementation to read directly from a memory buffer */
 #pragma once
 #ifndef AI_MEMORYIOSTREAM_H_INC
 #define AI_MEMORYIOSTREAM_H_INC
diff --git a/include/assimp/StreamReader.h b/include/assimp/StreamReader.h
index 1880f66b6..c6c17762d 100644
--- a/include/assimp/StreamReader.h
+++ b/include/assimp/StreamReader.h
@@ -207,7 +207,7 @@ public:
 
     // ---------------------------------------------------------------------
     /** Set current file pointer (Get it from #GetPtr). This is if you
-     *  prefer to do pointer arithmetics on your own or want to copy
+     *  prefer to do pointer arithmetic on your own or want to copy
      *  large chunks of data at once.
      *  @param p The new pointer, which is validated against the size
      *    limit and buffer boundaries. */
diff --git a/include/assimp/Vertex.h b/include/assimp/Vertex.h
index e749e3633..ad5ff476c 100644
--- a/include/assimp/Vertex.h
+++ b/include/assimp/Vertex.h
@@ -93,7 +93,7 @@ namespace Assimp    {
 
 // ------------------------------------------------------------------------------------------------
 /** Intermediate description a vertex with all possible components. Defines a full set of
- *  operators, so you may use such a 'Vertex' in basic arithmetics. All operators are applied
+ *  operators, so you may use such a 'Vertex' in basic arithmetic. All operators are applied
  *  to *all* vertex components equally. This is useful for stuff like interpolation
  *  or subdivision, but won't work if special handling is required for some vertex components. */
 // ------------------------------------------------------------------------------------------------
@@ -222,7 +222,7 @@ private:
     }
 
     // ----------------------------------------------------------------------------
-    /** This time binary arithmetics of v0 with a floating-point number */
+    /** This time binary arithmetic of v0 with a floating-point number */
     template <template <typename, typename, typename> class op> static Vertex BinaryOp(const Vertex& v0, ai_real f) {
         // this is a heavy task for the compiler to optimize ... *pray*
 
@@ -242,7 +242,7 @@ private:
     }
 
     // ----------------------------------------------------------------------------
-    /** This time binary arithmetics of v0 with a floating-point number */
+    /** This time binary arithmetic of v0 with a floating-point number */
     template <template <typename, typename, typename> class op> static Vertex BinaryOp(ai_real f, const Vertex& v0) {
         // this is a heavy task for the compiler to optimize ... *pray*
 
diff --git a/include/assimp/cexport.h b/include/assimp/cexport.h
index 44843af0e..47b59a62f 100644
--- a/include/assimp/cexport.h
+++ b/include/assimp/cexport.h
@@ -112,7 +112,7 @@ ASSIMP_API void aiReleaseExportFormatDescription(const C_STRUCT aiExportFormatDe
  *  export them again. Since the scene returned by the various importer functions
  *  is const, a modifiable copy is needed.
  *  @param pIn Valid scene to be copied
- *  @param pOut Receives a modifyable copy of the scene. Use aiFreeScene() to
+ *  @param pOut Receives a modifiable copy of the scene. Use aiFreeScene() to
  *    delete it again.
  */
 ASSIMP_API void aiCopyScene(const C_STRUCT aiScene *pIn,
diff --git a/include/assimp/postprocess.h b/include/assimp/postprocess.h
index 5e887b0b1..094fbf596 100644
--- a/include/assimp/postprocess.h
+++ b/include/assimp/postprocess.h
@@ -440,7 +440,7 @@ enum aiPostProcessSteps
      *
      * @note UV transformations are usually implemented in real-time apps by
      * transforming texture coordinates at vertex shader stage with a 3x3
-     * (homogenous) transformation matrix.
+     * (homogeneous) transformation matrix.
     */
     aiProcess_TransformUVCoords = 0x80000,
 
diff --git a/samples/SimpleAssimpViewX/MyDocument.h b/samples/SimpleAssimpViewX/MyDocument.h
index 67675e306..a9c5a3694 100644
--- a/samples/SimpleAssimpViewX/MyDocument.h
+++ b/samples/SimpleAssimpViewX/MyDocument.h
@@ -40,7 +40,7 @@
     NSMutableArray* modelMeshes;
     BOOL builtBuffers;
 
-    NSMutableDictionary* textureDictionary;	// Array of Dicionaries that map image filenames to textureIds
+    NSMutableDictionary* textureDictionary;	// Array of Dictionaries that map image filenames to textureIds
 }
 
 @property (retain) IBOutlet NSView* _view;
diff --git a/samples/SimpleOpenGL/Sample_SimpleOpenGL.c b/samples/SimpleOpenGL/Sample_SimpleOpenGL.c
index 7aa306ed4..c8ab7b3c2 100644
--- a/samples/SimpleOpenGL/Sample_SimpleOpenGL.c
+++ b/samples/SimpleOpenGL/Sample_SimpleOpenGL.c
@@ -361,7 +361,7 @@ int main(int argc, char **argv)
 	C_STRUCT aiLogStream stream;
 
 	if (argc < 2) {
-		print_error("No input model file specifed.");
+		print_error("No input model file specified.");
 		print_run_command(COMMAND_USAGE);
 		return EXIT_FAILURE;
 	}
diff --git a/samples/SimpleTexturedDirectx11/SimpleTexturedDirectx11/main.cpp b/samples/SimpleTexturedDirectx11/SimpleTexturedDirectx11/main.cpp
index 3f8d15320..f7b35024b 100644
--- a/samples/SimpleTexturedDirectx11/SimpleTexturedDirectx11/main.cpp
+++ b/samples/SimpleTexturedDirectx11/SimpleTexturedDirectx11/main.cpp
@@ -129,7 +129,7 @@ int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE /*hPrevInstance*/,
 	LPWSTR* argv = CommandLineToArgvW(GetCommandLineW(), &argc);
 	if (!argv) {
 		MessageBox(nullptr,
-			TEXT("An error occured while reading command line arguments."),
+			TEXT("An error occurred while reading command line arguments."),
 			TEXT("Error!"),
 			MB_ICONERROR | MB_OK);
 		return EXIT_FAILURE;
diff --git a/samples/SimpleTexturedOpenGL/SimpleTexturedOpenGL/src/model_loading.cpp b/samples/SimpleTexturedOpenGL/SimpleTexturedOpenGL/src/model_loading.cpp
index be0e651f1..48066f189 100644
--- a/samples/SimpleTexturedOpenGL/SimpleTexturedOpenGL/src/model_loading.cpp
+++ b/samples/SimpleTexturedOpenGL/SimpleTexturedOpenGL/src/model_loading.cpp
@@ -667,7 +667,7 @@ BOOL CreateGLWindow(const char* title, int width, int height, int bits, bool ful
 		dwStyle=WS_OVERLAPPEDWINDOW;					// Windows style
 	}
 
-	AdjustWindowRectEx(&WindowRect, dwStyle, FALSE, dwExStyle);		// Adjust Window To True Requestes Size
+	AdjustWindowRectEx(&WindowRect, dwStyle, FALSE, dwExStyle);		// Adjust Window To True Requested Size
 
 	if (nullptr == (g_hWnd=CreateWindowEx(dwExStyle,			// Extended Style For The Window
 								TEXT("OpenGL"),						// Class Name
diff --git a/test/unit/ImportExport/MDL/utMDLImporter_HL1_Nodes.cpp b/test/unit/ImportExport/MDL/utMDLImporter_HL1_Nodes.cpp
index 6fa92f950..1b1ed75d5 100644
--- a/test/unit/ImportExport/MDL/utMDLImporter_HL1_Nodes.cpp
+++ b/test/unit/ImportExport/MDL/utMDLImporter_HL1_Nodes.cpp
@@ -391,7 +391,7 @@ public:
                 // Unapply the transformation using the offset matrix.
                 aiMatrix4x4 unapplied_transform = scene_mesh_bone->mOffsetMatrix * transform;
 
-                // Ensure that we have, approximatively, the identity matrix.
+                // Ensure that we have, approximately, the identity matrix.
                 expect_equal_matrices(identity_matrix, unapplied_transform, TOLERANCE);
             }
         }
diff --git a/test/unit/utTriangulate.cpp b/test/unit/utTriangulate.cpp
index defec01f1..4f3e5cdc3 100644
--- a/test/unit/utTriangulate.cpp
+++ b/test/unit/utTriangulate.cpp
@@ -132,6 +132,6 @@ TEST_F(TriangulateProcessTest, testTriangulation) {
         }
     }
 
-    // we should have no valid normal vectors now necause we aren't a pure polygon mesh
+    // we should have no valid normal vectors now because we aren't a pure polygon mesh
     EXPECT_TRUE(pcMesh->mNormals == NULL);
 }
diff --git a/tools/assimp_cmd/Info.cpp b/tools/assimp_cmd/Info.cpp
index 2c35ba227..6e52fc981 100644
--- a/tools/assimp_cmd/Info.cpp
+++ b/tools/assimp_cmd/Info.cpp
@@ -313,7 +313,7 @@ int Assimp_Info (const char* const* params, unsigned int num) {
 
 	// Verbose and silent at the same time are not allowed
 	if ( verbose && silent ) {
-		printf("assimp info: Invalid arguments, verbose and silent at the same time are forbitten. ");
+		printf("assimp info: Invalid arguments, verbose and silent at the same time are forbidden. ");
 		return AssimpCmdInfoError::InvalidCombinaisonOfArguments;
 	}
 
diff --git a/tools/assimp_view/Display.cpp b/tools/assimp_view/Display.cpp
index ac9aa5329..c0770e7f2 100644
--- a/tools/assimp_view/Display.cpp
+++ b/tools/assimp_view/Display.cpp
@@ -90,7 +90,7 @@ D3DXVECTOR4 g_aclNormalColors[14] =
 
 
 //-------------------------------------------------------------------------------
-// Recursivly count the number of nodes in an asset's node graph
+// Recursively count the number of nodes in an asset's node graph
 // Used by LoadAsset()
 //-------------------------------------------------------------------------------
 void GetNodeCount(aiNode* pcNode, unsigned int* piCnt)
@@ -1535,7 +1535,7 @@ int CDisplay::RenderStereoView(const aiMatrix4x4& m)
         // (move back to the original position)
         g_sCamera.vPos -= g_sCamera.vRight * 0.03f;
 
-        // reenable all channels
+        // re-enable all channels
         g_piDevice->SetRenderState(D3DRS_COLORWRITEENABLE,
             D3DCOLORWRITEENABLE_RED |
             D3DCOLORWRITEENABLE_GREEN |
diff --git a/tools/assimp_view/Material.cpp b/tools/assimp_view/Material.cpp
index 100074445..002e4f522 100644
--- a/tools/assimp_view/Material.cpp
+++ b/tools/assimp_view/Material.cpp
@@ -1483,7 +1483,7 @@ int CMaterialManager::EndMaterial (AssetHelper::MeshHelper* pcMesh)
     pcMesh->piEffect->EndPass();
     pcMesh->piEffect->End();
 
-    // reenable culling if necessary
+    // re-enable culling if necessary
     if (pcMesh->twosided && g_sOptions.bCulling) {
         g_piDevice->SetRenderState(D3DRS_CULLMODE,D3DCULL_CCW);
     }
diff --git a/tools/assimp_view/MessageProc.cpp b/tools/assimp_view/MessageProc.cpp
index 56831eb2a..18424d78e 100644
--- a/tools/assimp_view/MessageProc.cpp
+++ b/tools/assimp_view/MessageProc.cpp
@@ -116,7 +116,7 @@ void MakeFileAssociations() {
     RegSetValueEx(hRegistry,"",0,REG_SZ,(const BYTE*)szTemp,(DWORD)strlen(szTemp)+1);
     RegCloseKey(hRegistry);
 
-    CLogDisplay::Instance().AddEntry("[OK] File assocations have been registered",
+    CLogDisplay::Instance().AddEntry("[OK] File associations have been registered",
         D3DCOLOR_ARGB(0xFF,0,0xFF,0));
 
     CLogDisplay::Instance().AddEntry(tmp.data,D3DCOLOR_ARGB(0xFF,0,0xFF,0));
@@ -1508,7 +1508,7 @@ INT_PTR CALLBACK MessageProc(HWND hwndDlg,UINT uMsg, WPARAM wParam,LPARAM lParam
             sRect.right -= sRect.left;
             sRect.bottom -= sRect.top;
 
-            // if the mouse klick was inside the viewer panel
+            // if the mouse click was inside the viewer panel
             // give the focus to it
             if (xPos > 0 && xPos < sRect.right && yPos > 0 && yPos < sRect.bottom)
                 {
diff --git a/tools/assimp_view/SceneAnimator.h b/tools/assimp_view/SceneAnimator.h
index 9010eb8cb..43c8d8eb7 100644
--- a/tools/assimp_view/SceneAnimator.h
+++ b/tools/assimp_view/SceneAnimator.h
@@ -125,7 +125,7 @@ public:
 
     // ----------------------------------------------------------------------------
     /** Calculates the node transformations for the scene. Call this to get
-     * uptodate results before calling one of the getters.
+     * up-to-date results before calling one of the getters.
      * @param pTime Current time. Can be an arbitrary range.
      */
     void Calculate(double pTime);
diff --git a/tools/assimp_view/assimp_view.cpp b/tools/assimp_view/assimp_view.cpp
index e780e2aaf..37e5f5429 100644
--- a/tools/assimp_view/assimp_view.cpp
+++ b/tools/assimp_view/assimp_view.cpp
@@ -489,7 +489,7 @@ int CreateAssetData() {
             nidx = 3;
             break;
         default:
-            CLogWindow::Instance().WriteLine("Unknown primitiv type");
+            CLogWindow::Instance().WriteLine("Unknown primitive type");
             break;
         };
 

From 1a9403e787aa319f8228c73c58b6b0eb860618a5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?IOhannes=20m=20zm=C3=B6lnig?= <zmoelnig@iem.at>
Date: Fri, 8 Oct 2021 08:55:02 +0200
Subject: [PATCH 10/20] Fix spelling error in comment in exported Pbrt file

See https://github.com/assimp/assimp/pull/4109#issuecomment-934747675
for a discussion that this is really a comment in the exported file,
and thus the fix should be harmless.
---
 code/Pbrt/PbrtExporter.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/code/Pbrt/PbrtExporter.cpp b/code/Pbrt/PbrtExporter.cpp
index 1c7024c28..c04ab6c19 100644
--- a/code/Pbrt/PbrtExporter.cpp
+++ b/code/Pbrt/PbrtExporter.cpp
@@ -614,7 +614,7 @@ void PbrtExporter::WriteMaterial(int m) {
                         eta != 1);
 
     mOutput << "#    - Constants: diffuse " << constantDiffuse << " specular " << constantSpecular <<
-        " transprency " << constantTransparency << " opacity " << constantOpacity <<
+        " transparency " << constantTransparency << " opacity " << constantOpacity <<
         " shininess " << constantShininess << " shininess strength " << constantShininessStrength <<
         " eta " << constantEta << "\n";
 

From a01a5b4e3a12baac929c11dff7962fdb24b1b772 Mon Sep 17 00:00:00 2001
From: Lassi Helynranta <lassi@helynranta.com>
Date: Sat, 9 Oct 2021 20:02:52 +0300
Subject: [PATCH 11/20] Added missing include

---
 code/Common/ImporterRegistry.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/code/Common/ImporterRegistry.cpp b/code/Common/ImporterRegistry.cpp
index 5df096166..77a365844 100644
--- a/code/Common/ImporterRegistry.cpp
+++ b/code/Common/ImporterRegistry.cpp
@@ -46,6 +46,7 @@ directly (unless you are adding new loaders), instead use the
 corresponding preprocessor flag to selectively disable formats.
 */
 
+#include <assimp/anim.h>
 #include <assimp/BaseImporter.h>
 #include <vector>
 #include <cstdlib>

From 4caae783ae22bee7f2373dc00eb94e47169257ba Mon Sep 17 00:00:00 2001
From: Kim Kulling <kim.kulling@googlemail.com>
Date: Sun, 17 Oct 2021 15:09:44 +0200
Subject: [PATCH 12/20] Disable dump when export is not supported.

---
 tools/assimp_cmd/WriteDump.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tools/assimp_cmd/WriteDump.cpp b/tools/assimp_cmd/WriteDump.cpp
index fd8839a17..f35630568 100644
--- a/tools/assimp_cmd/WriteDump.cpp
+++ b/tools/assimp_cmd/WriteDump.cpp
@@ -66,6 +66,8 @@ const char *AICMD_MSG_DUMP_HELP =
 FILE *out = nullptr;
 bool shortened = false;
 
+#ifndef ASSIMP_BUILD_NO_EXPORT
+
 // -----------------------------------------------------------------------------------
 int Assimp_Dump(const char *const *params, unsigned int num) {
     const char *fail = "assimp dump: Invalid number of arguments. "
@@ -162,3 +164,9 @@ int Assimp_Dump(const char *const *params, unsigned int num) {
     printf("assimp dump: Wrote output dump %s\n", cur_out.c_str());
     return AssimpCmdError::Success;
 }
+#else
+int Assimp_Dump(const char *const *, unsigned int ) {
+    printf("assimp dump: Export disabled.\n");
+    return AssimpCmdError::UnrecognizedCommand;
+}
+#endif
\ No newline at end of file

From 0e3d0585041b7ac61758bfc2bcee8a361b1b62a3 Mon Sep 17 00:00:00 2001
From: Kim Kulling <kim.kulling@googlemail.com>
Date: Sun, 17 Oct 2021 15:10:25 +0200
Subject: [PATCH 13/20] Add some exporter macros.

---
 code/AssetLib/3MF/D3MFExporter.h          |  6 ++++--
 code/AssetLib/Assbin/AssbinExporter.h     |  4 +++-
 code/AssetLib/Assbin/AssbinFileWriter.cpp | 23 +++++++++++------------
 test/unit/ImportExport/utExporter.cpp     |  4 ++++
 test/unit/utColladaImportExport.cpp       |  4 ++++
 5 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/code/AssetLib/3MF/D3MFExporter.h b/code/AssetLib/3MF/D3MFExporter.h
index 3da74fb37..df25e305e 100644
--- a/code/AssetLib/3MF/D3MFExporter.h
+++ b/code/AssetLib/3MF/D3MFExporter.h
@@ -101,9 +101,11 @@ private:
     std::vector<OpcPackageRelationship*> mRelations;
 };
 
-#endif // ASSIMP_BUILD_NO_3MF_EXPORTER
-#endif // ASSIMP_BUILD_NO_EXPORT
 
 } // Namespace D3MF
 } // Namespace Assimp
 
+#endif // ASSIMP_BUILD_NO_3MF_EXPORTER
+#endif // ASSIMP_BUILD_NO_EXPORT
+
+
diff --git a/code/AssetLib/Assbin/AssbinExporter.h b/code/AssetLib/Assbin/AssbinExporter.h
index 4871b5021..b6f2acd3d 100644
--- a/code/AssetLib/Assbin/AssbinExporter.h
+++ b/code/AssetLib/Assbin/AssbinExporter.h
@@ -48,11 +48,13 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <assimp/defs.h>
 
+#ifndef ASSIMP_BUILD_NO_EXPORT
+
 // nothing really needed here - reserved for future use like properties
 namespace Assimp {
 
 void ASSIMP_API ExportSceneAssbin(const char* pFile, IOSystem* pIOSystem, const aiScene* pScene, const ExportProperties* /*pProperties*/);
 
 }
-
+#endif 
 #endif // AI_ASSBINEXPORTER_H_INC
diff --git a/code/AssetLib/Assbin/AssbinFileWriter.cpp b/code/AssetLib/Assbin/AssbinFileWriter.cpp
index 2519b0b93..21bfd8512 100644
--- a/code/AssetLib/Assbin/AssbinFileWriter.cpp
+++ b/code/AssetLib/Assbin/AssbinFileWriter.cpp
@@ -43,13 +43,11 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "AssbinFileWriter.h"
-
 #include "Common/assbin_chunks.h"
 #include "PostProcessing/ProcessHelper.h"
 
 #include <assimp/Exceptional.h>
 #include <assimp/version.h>
-#include <assimp/Exporter.hpp>
 #include <assimp/IOStream.hpp>
 
 #ifdef ASSIMP_BUILD_NO_OWN_ZLIB
@@ -58,7 +56,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include "../contrib/zlib/zlib.h"
 #endif
 
-#include <time.h>
+#include <ctime>
 
 #if _MSC_VER
 #pragma warning(push)
@@ -277,7 +275,7 @@ public:
         // empty
     }
 
-    virtual ~AssbinChunkWriter() {
+    ~AssbinChunkWriter() override {
         if (container) {
             container->Write(&magic, sizeof(uint32_t), 1);
             container->Write(&cursor, sizeof(uint32_t), 1);
@@ -288,26 +286,27 @@ public:
 
     void *GetBufferPointer() { return buffer; }
 
-    // -------------------------------------------------------------------
-    virtual size_t Read(void * /*pvBuffer*/, size_t /*pSize*/, size_t /*pCount*/) {
+    size_t Read(void * /*pvBuffer*/, size_t /*pSize*/, size_t /*pCount*/) override {
         return 0;
     }
-    virtual aiReturn Seek(size_t /*pOffset*/, aiOrigin /*pOrigin*/) {
+    
+    aiReturn Seek(size_t /*pOffset*/, aiOrigin /*pOrigin*/) override {
         return aiReturn_FAILURE;
     }
-    virtual size_t Tell() const {
+    
+    size_t Tell() const override {
         return cursor;
     }
-    virtual void Flush() {
+    
+    void Flush() override {
         // not implemented
     }
 
-    virtual size_t FileSize() const {
+    size_t FileSize() const override {
         return cursor;
     }
 
-    // -------------------------------------------------------------------
-    virtual size_t Write(const void *pvBuffer, size_t pSize, size_t pCount) {
+    size_t Write(const void *pvBuffer, size_t pSize, size_t pCount) override {
         pSize *= pCount;
         if (cursor + pSize > cur_size) {
             Grow(cursor + pSize);
diff --git a/test/unit/ImportExport/utExporter.cpp b/test/unit/ImportExport/utExporter.cpp
index b1e1ec362..e153d3e4d 100644
--- a/test/unit/ImportExport/utExporter.cpp
+++ b/test/unit/ImportExport/utExporter.cpp
@@ -45,6 +45,8 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 using namespace Assimp;
 
+#ifndef ASSIMP_BUILD_NO_EXPORT
+
 class TestProgressHandler : public ProgressHandler {
 public:
     TestProgressHandler() :
@@ -101,3 +103,5 @@ TEST_F(ExporterTest, ExporterIdTest) {
     const aiExportFormatDesc *desc = exporter.GetExportFormatDescription(exportFormatCount);
     EXPECT_EQ(nullptr, desc) << "More exporters than claimed";
 }
+
+#endif
\ No newline at end of file
diff --git a/test/unit/utColladaImportExport.cpp b/test/unit/utColladaImportExport.cpp
index 76a39336e..44f988852 100644
--- a/test/unit/utColladaImportExport.cpp
+++ b/test/unit/utColladaImportExport.cpp
@@ -233,6 +233,8 @@ unsigned int GetMeshUseCount(const aiNode *rootNode) {
     return result;
 }
 
+#ifndef ASSIMP_BUILD_NO_EXPORT
+
 TEST_F(utColladaImportExport, exportRootNodeMeshTest) {
     Assimp::Importer importer;
     Assimp::Exporter exporter;
@@ -342,6 +344,8 @@ TEST_F(utColladaImportExport, exporterUniqueIdsTest) {
     ImportAsNames(outFileNamed, scene);
 }
 
+#endif
+
 class utColladaZaeImportExport : public AbstractImportExportBase {
 public:
     virtual bool importerTest() final {

From e7b9118b96de89df351e06cc53517b46a9b4d512 Mon Sep 17 00:00:00 2001
From: Kim Kulling <kimkulling@users.noreply.github.com>
Date: Sun, 17 Oct 2021 21:04:18 +0200
Subject: [PATCH 14/20] Delete fast_atof.h

---
 contrib/irrXML/fast_atof.h | 139 -------------------------------------
 1 file changed, 139 deletions(-)
 delete mode 100644 contrib/irrXML/fast_atof.h

diff --git a/contrib/irrXML/fast_atof.h b/contrib/irrXML/fast_atof.h
deleted file mode 100644
index 14212429b..000000000
--- a/contrib/irrXML/fast_atof.h
+++ /dev/null
@@ -1,139 +0,0 @@
-// Copyright (C) 2002-2005 Nikolaus Gebhardt
-// This file is part of the "Irrlicht Engine" and the "irrXML" project.
-// For conditions of distribution and use, see copyright notice in irrlicht.h and irrXML.h
-
-#ifndef __FAST_A_TO_F_H_INCLUDED__
-#define __FAST_A_TO_F_H_INCLUDED__
-
-#include <stdlib.h>
-#include <math.h>
-
-namespace irr
-{
-namespace core
-{
-
-const float fast_atof_table[] =	{
-										0.f,
-										0.1f,
-										0.01f,
-										0.001f,
-										0.0001f,
-										0.00001f,
-										0.000001f,
-										0.0000001f,
-										0.00000001f,
-										0.000000001f,
-										0.0000000001f,
-										0.00000000001f,
-										0.000000000001f,
-										0.0000000000001f,
-										0.00000000000001f,
-										0.000000000000001f
-									};
-
-//! Provides a fast function for converting a string into a float,
-//! about 6 times faster than atof in win32.
-// If you find any bugs, please send them to me, niko (at) irrlicht3d.org.
-inline char* fast_atof_move(char* c, float& out)
-{
-	bool inv = false;
-	char *t;
-	float f;
-
-	if (*c=='-')
-	{
-		c++;
-		inv = true;
-	}
-
-	f = (float)strtol(c, &t, 10);
-
-	c = t;
-
-	if (*c == '.')
-	{
-		c++;
-
-		float pl = (float)strtol(c, &t, 10);
-		pl *= fast_atof_table[t-c];
-
-		f += pl;
-
-		c = t;
-
-		if (*c == 'e')
-		{
-			++c;
-			float exp = (float)strtol(c, &t, 10);
-			f *= (float)pow(10.0f, exp);
-			c = t;
-		}
-	}
-
-	if (inv)
-		f *= -1.0f;
-	
-	out = f;
-	return c;
-}
-
-//! Provides a fast function for converting a string into a float,
-//! about 6 times faster than atof in win32.
-// If you find any bugs, please send them to me, niko (at) irrlicht3d.org.
-inline const char* fast_atof_move_const(const char* c, float& out)
-{
-	bool inv = false;
-	char *t;
-	float f;
-
-	if (*c=='-')
-	{
-		c++;
-		inv = true;
-	}
-
-	f = (float)strtol(c, &t, 10);
-
-	c = t;
-
-	if (*c == '.')
-	{
-		c++;
-
-		float pl = (float)strtol(c, &t, 10);
-		pl *= fast_atof_table[t-c];
-
-		f += pl;
-
-		c = t;
-
-		if (*c == 'e') 
-		{ 
-			++c; 
-			f32 exp = (f32)strtol(c, &t, 10); 
-			f *= (f32)powf(10.0f, exp); 
-			c = t; 
-		}
-	}
-
-	if (inv)
-		f *= -1.0f;
-	
-	out = f;
-	return c;
-}
-
-
-inline float fast_atof(const char* c)
-{
-	float ret;
-	fast_atof_move_const(c, ret);
-	return ret;
-}
-
-} // end namespace core
-}// end namespace irr
-
-#endif
-

From 5b13b97f27ef6362b0d63a16c536fb26b224efef Mon Sep 17 00:00:00 2001
From: Malcolm Tyrrell <matyrr@microsoft.com>
Date: Tue, 19 Oct 2021 14:22:28 +0100
Subject: [PATCH 15/20] Ensure the usage pattern of SpatialSort.

---
 code/Common/SpatialSort.cpp  | 15 ++++++++++++---
 include/assimp/SpatialSort.h |  3 +++
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/code/Common/SpatialSort.cpp b/code/Common/SpatialSort.cpp
index 2bd848164..3ef9f055b 100644
--- a/code/Common/SpatialSort.cpp
+++ b/code/Common/SpatialSort.cpp
@@ -58,14 +58,16 @@ const aiVector3D PlaneInit(0.8523f, 0.34321f, 0.5736f);
 // define the reference plane. We choose some arbitrary vector away from all basic axes
 // in the hope that no model spreads all its vertices along this plane.
 SpatialSort::SpatialSort(const aiVector3D *pPositions, unsigned int pNumPositions, unsigned int pElementOffset) :
-        mPlaneNormal(PlaneInit) {
+        mPlaneNormal(PlaneInit),
+        mFinalized(false) {
     mPlaneNormal.Normalize();
     Fill(pPositions, pNumPositions, pElementOffset);
 }
 
 // ------------------------------------------------------------------------------------------------
 SpatialSort::SpatialSort() :
-        mPlaneNormal(PlaneInit) {
+        mPlaneNormal(PlaneInit),
+        mFinalized(false) {
     mPlaneNormal.Normalize();
 }
 
@@ -80,21 +82,25 @@ void SpatialSort::Fill(const aiVector3D *pPositions, unsigned int pNumPositions,
         unsigned int pElementOffset,
         bool pFinalize /*= true */) {
     mPositions.clear();
+    mFinalized = false;
     Append(pPositions, pNumPositions, pElementOffset, pFinalize);
+    mFinalized = pFinalize;
 }
 
 // ------------------------------------------------------------------------------------------------
 void SpatialSort::Finalize() {
     std::sort(mPositions.begin(), mPositions.end());
+    mFinalized = true;
 }
 
 // ------------------------------------------------------------------------------------------------
 void SpatialSort::Append(const aiVector3D *pPositions, unsigned int pNumPositions,
         unsigned int pElementOffset,
         bool pFinalize /*= true */) {
+    ai_assert(!mFinalized && "You cannot add positions to the SpatialSort object after it has been finalized.");
     // store references to all given positions along with their distance to the reference plane
     const size_t initial = mPositions.size();
-    mPositions.reserve(initial + (pFinalize ? pNumPositions : pNumPositions * 2));
+    mPositions.reserve(initial + pNumPositions);
     for (unsigned int a = 0; a < pNumPositions; a++) {
         const char *tempPointer = reinterpret_cast<const char *>(pPositions);
         const aiVector3D *vec = reinterpret_cast<const aiVector3D *>(tempPointer + a * pElementOffset);
@@ -114,6 +120,7 @@ void SpatialSort::Append(const aiVector3D *pPositions, unsigned int pNumPosition
 // Returns an iterator for all positions close to the given position.
 void SpatialSort::FindPositions(const aiVector3D &pPosition,
         ai_real pRadius, std::vector<unsigned int> &poResults) const {
+    ai_assert(mFinalized && "The SpatialSort object must be finalized before FindPositions can be called.");
     const ai_real dist = pPosition * mPlaneNormal;
     const ai_real minDist = dist - pRadius, maxDist = dist + pRadius;
 
@@ -229,6 +236,7 @@ BinFloat ToBinary(const ai_real &pValue) {
 // Fills an array with indices of all positions identical to the given position. In opposite to
 // FindPositions(), not an epsilon is used but a (very low) tolerance of four floating-point units.
 void SpatialSort::FindIdenticalPositions(const aiVector3D &pPosition, std::vector<unsigned int> &poResults) const {
+    ai_assert(mFinalized && "The SpatialSort object must be finalized before FindIdenticalPositions can be called.");
     // Epsilons have a huge disadvantage: they are of constant precision, while floating-point
     //  values are of log2 precision. If you apply e=0.01 to 100, the epsilon is rather small, but
     //  if you apply it to 0.001, it is enormous.
@@ -297,6 +305,7 @@ void SpatialSort::FindIdenticalPositions(const aiVector3D &pPosition, std::vecto
 
 // ------------------------------------------------------------------------------------------------
 unsigned int SpatialSort::GenerateMappingTable(std::vector<unsigned int> &fill, ai_real pRadius) const {
+    ai_assert(mFinalized && "The SpatialSort object must be finalized before GenerateMappingTable can be called.");
     fill.resize(mPositions.size(), UINT_MAX);
     ai_real dist, maxDist;
 
diff --git a/include/assimp/SpatialSort.h b/include/assimp/SpatialSort.h
index 39ebae77b..5db23c86b 100644
--- a/include/assimp/SpatialSort.h
+++ b/include/assimp/SpatialSort.h
@@ -168,6 +168,9 @@ protected:
 
     // all positions, sorted by distance to the sorting plane
     std::vector<Entry> mPositions;
+
+    // False until the Finalize method is called.
+    bool mFinalized;
 };
 
 } // end of namespace Assimp

From 4d10f5d133af0c88aa3557e049709e3fa44f53b6 Mon Sep 17 00:00:00 2001
From: Malcolm Tyrrell <matyrr@microsoft.com>
Date: Wed, 20 Oct 2021 12:47:44 +0100
Subject: [PATCH 16/20] Move distance initialization to Finalize.

---
 code/Common/SpatialSort.cpp  |  8 ++++----
 include/assimp/SpatialSort.h | 12 +++++++-----
 2 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/code/Common/SpatialSort.cpp b/code/Common/SpatialSort.cpp
index 3ef9f055b..a8afbfaf6 100644
--- a/code/Common/SpatialSort.cpp
+++ b/code/Common/SpatialSort.cpp
@@ -89,6 +89,9 @@ void SpatialSort::Fill(const aiVector3D *pPositions, unsigned int pNumPositions,
 
 // ------------------------------------------------------------------------------------------------
 void SpatialSort::Finalize() {
+    for (unsigned int i = 0; i < mPositions.size(); i++) {
+        mPositions[i].mDistance = mPositions[i].mPosition * mPlaneNormal;
+    }
     std::sort(mPositions.begin(), mPositions.end());
     mFinalized = true;
 }
@@ -104,10 +107,7 @@ void SpatialSort::Append(const aiVector3D *pPositions, unsigned int pNumPosition
     for (unsigned int a = 0; a < pNumPositions; a++) {
         const char *tempPointer = reinterpret_cast<const char *>(pPositions);
         const aiVector3D *vec = reinterpret_cast<const aiVector3D *>(tempPointer + a * pElementOffset);
-
-        // store position by index and distance
-        ai_real distance = *vec * mPlaneNormal;
-        mPositions.push_back(Entry(static_cast<unsigned int>(a + initial), *vec, distance));
+        mPositions.push_back(Entry(static_cast<unsigned int>(a + initial), *vec));
     }
 
     if (pFinalize) {
diff --git a/include/assimp/SpatialSort.h b/include/assimp/SpatialSort.h
index 5db23c86b..475a11d7c 100644
--- a/include/assimp/SpatialSort.h
+++ b/include/assimp/SpatialSort.h
@@ -51,6 +51,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <assimp/types.h>
 #include <vector>
+#include <limits>
 
 namespace Assimp {
 
@@ -150,16 +151,17 @@ protected:
     struct Entry {
         unsigned int mIndex; ///< The vertex referred by this entry
         aiVector3D mPosition; ///< Position
-        ai_real mDistance; ///< Distance of this vertex to the sorting plane
+        /// Distance of this vertex to the sorting plane. This is set by Finalize.
+        ai_real mDistance; 
 
         Entry() AI_NO_EXCEPT
-                : mIndex(999999999),
+                : mIndex(std::numeric_limits<unsigned int>::max()),
                   mPosition(),
-                  mDistance(99999.) {
+                  mDistance(std::numeric_limits<ai_real>::max()) {
             // empty
         }
-        Entry(unsigned int pIndex, const aiVector3D &pPosition, ai_real pDistance) :
-                mIndex(pIndex), mPosition(pPosition), mDistance(pDistance) {
+        Entry(unsigned int pIndex, const aiVector3D &pPosition) :
+                mIndex(pIndex), mPosition(pPosition) {
             // empty
         }
 

From c644f9d71979143674686d88534bf738fd27bfd6 Mon Sep 17 00:00:00 2001
From: Malcolm Tyrrell <matyrr@microsoft.com>
Date: Wed, 20 Oct 2021 15:08:08 +0100
Subject: [PATCH 17/20] Subtract the centroid

---
 code/Common/SpatialSort.cpp        | 12 +++++++----
 include/assimp/SpatialSort.h       |  7 ++++--
 test/unit/Common/utSpatialSort.cpp | 34 ++++++++++++++++++++++++++++++
 3 files changed, 47 insertions(+), 6 deletions(-)

diff --git a/code/Common/SpatialSort.cpp b/code/Common/SpatialSort.cpp
index a8afbfaf6..08a7c55df 100644
--- a/code/Common/SpatialSort.cpp
+++ b/code/Common/SpatialSort.cpp
@@ -89,8 +89,12 @@ void SpatialSort::Fill(const aiVector3D *pPositions, unsigned int pNumPositions,
 
 // ------------------------------------------------------------------------------------------------
 void SpatialSort::Finalize() {
+    const ai_real scale = 1.0f / mPositions.size();
     for (unsigned int i = 0; i < mPositions.size(); i++) {
-        mPositions[i].mDistance = mPositions[i].mPosition * mPlaneNormal;
+        mCentroid += scale * mPositions[i].mPosition; 
+    }
+    for (unsigned int i = 0; i < mPositions.size(); i++) {
+        mPositions[i].mDistance = (mPositions[i].mPosition - mCentroid) * mPlaneNormal;
     }
     std::sort(mPositions.begin(), mPositions.end());
     mFinalized = true;
@@ -121,7 +125,7 @@ void SpatialSort::Append(const aiVector3D *pPositions, unsigned int pNumPosition
 void SpatialSort::FindPositions(const aiVector3D &pPosition,
         ai_real pRadius, std::vector<unsigned int> &poResults) const {
     ai_assert(mFinalized && "The SpatialSort object must be finalized before FindPositions can be called.");
-    const ai_real dist = pPosition * mPlaneNormal;
+    const ai_real dist = (pPosition - mCentroid) * mPlaneNormal;
     const ai_real minDist = dist - pRadius, maxDist = dist + pRadius;
 
     // clear the array
@@ -262,7 +266,7 @@ void SpatialSort::FindIdenticalPositions(const aiVector3D &pPosition, std::vecto
 
     // Convert the plane distance to its signed integer representation so the ULPs tolerance can be
     //  applied. For some reason, VC won't optimize two calls of the bit pattern conversion.
-    const BinFloat minDistBinary = ToBinary(pPosition * mPlaneNormal) - distanceToleranceInULPs;
+    const BinFloat minDistBinary = ToBinary((pPosition - mCentroid) * mPlaneNormal) - distanceToleranceInULPs;
     const BinFloat maxDistBinary = minDistBinary + 2 * distanceToleranceInULPs;
 
     // clear the array in this strange fashion because a simple clear() would also deallocate
@@ -312,7 +316,7 @@ unsigned int SpatialSort::GenerateMappingTable(std::vector<unsigned int> &fill,
     unsigned int t = 0;
     const ai_real pSquared = pRadius * pRadius;
     for (size_t i = 0; i < mPositions.size();) {
-        dist = mPositions[i].mPosition * mPlaneNormal;
+        dist = (mPositions[i].mPosition - mCentroid) * mPlaneNormal;
         maxDist = dist + pRadius;
 
         fill[mPositions[i].mIndex] = t;
diff --git a/include/assimp/SpatialSort.h b/include/assimp/SpatialSort.h
index 475a11d7c..39f863b15 100644
--- a/include/assimp/SpatialSort.h
+++ b/include/assimp/SpatialSort.h
@@ -143,7 +143,7 @@ public:
             ai_real pRadius) const;
 
 protected:
-    /** Normal of the sorting plane, normalized. The center is always at (0, 0, 0) */
+    /** Normal of the sorting plane, normalized. */
     aiVector3D mPlaneNormal;
 
     /** An entry in a spatially sorted position array. Consists of a vertex index,
@@ -171,8 +171,11 @@ protected:
     // all positions, sorted by distance to the sorting plane
     std::vector<Entry> mPositions;
 
-    // False until the Finalize method is called.
+    /// false until the Finalize method is called.
     bool mFinalized;
+
+    /// The centroid of the positions. Calculated in Finalize.
+    aiVector3D mCentroid;
 };
 
 } // end of namespace Assimp
diff --git a/test/unit/Common/utSpatialSort.cpp b/test/unit/Common/utSpatialSort.cpp
index 94dfd2dc4..ba411d99f 100644
--- a/test/unit/Common/utSpatialSort.cpp
+++ b/test/unit/Common/utSpatialSort.cpp
@@ -82,3 +82,37 @@ TEST_F(utSpatialSort, findPositionsTest) {
     sSort.FindPositions(vecs[0], 0.01f, indices);
     EXPECT_EQ(1u, indices.size());
 }
+
+TEST_F(utSpatialSort, highlyDisplacedPositionsTest) {
+    constexpr unsigned int verticesPerAxis = 10;
+    constexpr ai_real step = 0.001f;
+    constexpr ai_real offset = 5000.0f - (0.5f * verticesPerAxis * step);
+    constexpr unsigned int totalNumPositions = verticesPerAxis * verticesPerAxis * verticesPerAxis;
+    aiVector3D* positions = new aiVector3D[totalNumPositions];
+    for (unsigned int x = 0; x < verticesPerAxis; ++x) {
+        for (unsigned int y = 0; y < verticesPerAxis; ++y) {
+            for (unsigned int z = 0; z < verticesPerAxis; ++z) {
+                const unsigned int index = (x * verticesPerAxis * verticesPerAxis) + (y * verticesPerAxis) + z;
+                positions[index] = aiVector3D(offset + (x * step), offset + (y * step), offset + (z * step));
+            }
+        }
+    }
+
+    SpatialSort sSort;
+    sSort.Fill(positions, totalNumPositions, sizeof(aiVector3D));
+
+    // Enough to pick up the neighboring vertices, but not the neighbors' neighbors.
+    const ai_real epsilon = 1.1f * step;
+    std::vector<unsigned int> indices;
+    // Iterate through the interior points of the cube.
+    for (unsigned int x = 1; x < verticesPerAxis - 1; ++x) {
+        for (unsigned int y = 1; y < verticesPerAxis - 1; ++y) {
+            for (unsigned int z = 1; z < verticesPerAxis - 1; ++z) {
+                const unsigned int index = (x * verticesPerAxis * verticesPerAxis) + (y * verticesPerAxis) + z;
+                sSort.FindPositions(positions[index], epsilon, indices);
+                ASSERT_EQ(7u, indices.size());
+            }
+        }
+    }
+    delete[] positions;
+}

From 4ba99c1bb08709fc7e0106d626af0f9e3c95fee9 Mon Sep 17 00:00:00 2001
From: Malcolm Tyrrell <matyrr@microsoft.com>
Date: Wed, 20 Oct 2021 16:15:00 +0100
Subject: [PATCH 18/20] Comments

---
 test/unit/Common/utSpatialSort.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/test/unit/Common/utSpatialSort.cpp b/test/unit/Common/utSpatialSort.cpp
index ba411d99f..8ebae76e8 100644
--- a/test/unit/Common/utSpatialSort.cpp
+++ b/test/unit/Common/utSpatialSort.cpp
@@ -84,8 +84,10 @@ TEST_F(utSpatialSort, findPositionsTest) {
 }
 
 TEST_F(utSpatialSort, highlyDisplacedPositionsTest) {
+    // Make a cube of positions, and then query it using the SpatialSort object.
     constexpr unsigned int verticesPerAxis = 10;
     constexpr ai_real step = 0.001f;
+    // Note the large constant offset here.
     constexpr ai_real offset = 5000.0f - (0.5f * verticesPerAxis * step);
     constexpr unsigned int totalNumPositions = verticesPerAxis * verticesPerAxis * verticesPerAxis;
     aiVector3D* positions = new aiVector3D[totalNumPositions];
@@ -101,10 +103,10 @@ TEST_F(utSpatialSort, highlyDisplacedPositionsTest) {
     SpatialSort sSort;
     sSort.Fill(positions, totalNumPositions, sizeof(aiVector3D));
 
-    // Enough to pick up the neighboring vertices, but not the neighbors' neighbors.
+    // Enough to pick up a point and its 6 immediate neighbors, but not any other point.
     const ai_real epsilon = 1.1f * step;
     std::vector<unsigned int> indices;
-    // Iterate through the interior points of the cube.
+    // Iterate through the _interior_ points of the cube.
     for (unsigned int x = 1; x < verticesPerAxis - 1; ++x) {
         for (unsigned int y = 1; y < verticesPerAxis - 1; ++y) {
             for (unsigned int z = 1; z < verticesPerAxis - 1; ++z) {

From db0127859aeb27add83afc9440f41e1a0a8db6db Mon Sep 17 00:00:00 2001
From: Malcolm Tyrrell <matyrr@microsoft.com>
Date: Thu, 21 Oct 2021 08:39:44 +0100
Subject: [PATCH 19/20] CalculateDistance method

---
 code/Common/SpatialSort.cpp        | 11 ++++++++---
 include/assimp/SpatialSort.h       | 17 ++++++++++++-----
 test/unit/Common/utSpatialSort.cpp |  2 +-
 3 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/code/Common/SpatialSort.cpp b/code/Common/SpatialSort.cpp
index 08a7c55df..9b96887ac 100644
--- a/code/Common/SpatialSort.cpp
+++ b/code/Common/SpatialSort.cpp
@@ -87,6 +87,11 @@ void SpatialSort::Fill(const aiVector3D *pPositions, unsigned int pNumPositions,
     mFinalized = pFinalize;
 }
 
+// ------------------------------------------------------------------------------------------------
+ai_real SpatialSort::CalculateDistance(const aiVector3D &pPosition) const {
+    return (pPosition - mCentroid) * mPlaneNormal;
+}
+
 // ------------------------------------------------------------------------------------------------
 void SpatialSort::Finalize() {
     const ai_real scale = 1.0f / mPositions.size();
@@ -94,7 +99,7 @@ void SpatialSort::Finalize() {
         mCentroid += scale * mPositions[i].mPosition; 
     }
     for (unsigned int i = 0; i < mPositions.size(); i++) {
-        mPositions[i].mDistance = (mPositions[i].mPosition - mCentroid) * mPlaneNormal;
+        mPositions[i].mDistance = CalculateDistance(mPositions[i].mPosition);
     }
     std::sort(mPositions.begin(), mPositions.end());
     mFinalized = true;
@@ -125,7 +130,7 @@ void SpatialSort::Append(const aiVector3D *pPositions, unsigned int pNumPosition
 void SpatialSort::FindPositions(const aiVector3D &pPosition,
         ai_real pRadius, std::vector<unsigned int> &poResults) const {
     ai_assert(mFinalized && "The SpatialSort object must be finalized before FindPositions can be called.");
-    const ai_real dist = (pPosition - mCentroid) * mPlaneNormal;
+    const ai_real dist = CalculateDistance(pPosition);
     const ai_real minDist = dist - pRadius, maxDist = dist + pRadius;
 
     // clear the array
@@ -266,7 +271,7 @@ void SpatialSort::FindIdenticalPositions(const aiVector3D &pPosition, std::vecto
 
     // Convert the plane distance to its signed integer representation so the ULPs tolerance can be
     //  applied. For some reason, VC won't optimize two calls of the bit pattern conversion.
-    const BinFloat minDistBinary = ToBinary((pPosition - mCentroid) * mPlaneNormal) - distanceToleranceInULPs;
+    const BinFloat minDistBinary = ToBinary(CalculateDistance(pPosition)) - distanceToleranceInULPs;
     const BinFloat maxDistBinary = minDistBinary + 2 * distanceToleranceInULPs;
 
     // clear the array in this strange fashion because a simple clear() would also deallocate
diff --git a/include/assimp/SpatialSort.h b/include/assimp/SpatialSort.h
index 39f863b15..c0c4a0292 100644
--- a/include/assimp/SpatialSort.h
+++ b/include/assimp/SpatialSort.h
@@ -143,9 +143,19 @@ public:
             ai_real pRadius) const;
 
 protected:
-    /** Normal of the sorting plane, normalized. */
+    /** Return the distance to the sorting plane. */
+    ai_real CalculateDistance(const aiVector3D &pPosition) const;
+
+protected:
+    /** Normal of the sorting plane, normalized.
+     */
     aiVector3D mPlaneNormal;
 
+    /** The centroid of the positions, which is used as a point on the sorting plane
+     * when calculating distance. This value is calculated in Finalize.
+    */
+    aiVector3D mCentroid;
+
     /** An entry in a spatially sorted position array. Consists of a vertex index,
      * its position and its pre-calculated distance from the reference plane */
     struct Entry {
@@ -161,7 +171,7 @@ protected:
             // empty
         }
         Entry(unsigned int pIndex, const aiVector3D &pPosition) :
-                mIndex(pIndex), mPosition(pPosition) {
+                mIndex(pIndex), mPosition(pPosition), mDistance(std::numeric_limits<ai_real>::max()) {
             // empty
         }
 
@@ -173,9 +183,6 @@ protected:
 
     /// false until the Finalize method is called.
     bool mFinalized;
-
-    /// The centroid of the positions. Calculated in Finalize.
-    aiVector3D mCentroid;
 };
 
 } // end of namespace Assimp
diff --git a/test/unit/Common/utSpatialSort.cpp b/test/unit/Common/utSpatialSort.cpp
index 8ebae76e8..f0b694c7d 100644
--- a/test/unit/Common/utSpatialSort.cpp
+++ b/test/unit/Common/utSpatialSort.cpp
@@ -103,7 +103,7 @@ TEST_F(utSpatialSort, highlyDisplacedPositionsTest) {
     SpatialSort sSort;
     sSort.Fill(positions, totalNumPositions, sizeof(aiVector3D));
 
-    // Enough to pick up a point and its 6 immediate neighbors, but not any other point.
+    // Enough to find a point and its 6 immediate neighbors, but not any other point.
     const ai_real epsilon = 1.1f * step;
     std::vector<unsigned int> indices;
     // Iterate through the _interior_ points of the cube.

From e01b488075209cc76af56620539d345c6e0395e6 Mon Sep 17 00:00:00 2001
From: Kim Kulling <kimkulling@users.noreply.github.com>
Date: Tue, 26 Oct 2021 22:06:10 +0200
Subject: [PATCH 20/20] Remove dead code.

---
 code/AssetLib/3MF/XmlSerializer.cpp | 1 -
 1 file changed, 1 deletion(-)

diff --git a/code/AssetLib/3MF/XmlSerializer.cpp b/code/AssetLib/3MF/XmlSerializer.cpp
index 7a33d08ed..985286fa7 100644
--- a/code/AssetLib/3MF/XmlSerializer.cpp
+++ b/code/AssetLib/3MF/XmlSerializer.cpp
@@ -159,7 +159,6 @@ bool parseColor(const char *color, aiColor4D &diffuse) {
         return false;
     }
 
-    //const char *buf(color);
     if ('#' != color[0]) {
         return false;
     }