diff --git a/code/AssetLib/FBX/FBXExporter.cpp b/code/AssetLib/FBX/FBXExporter.cpp index cbaf83f0f..ae210eb1a 100644 --- a/code/AssetLib/FBX/FBXExporter.cpp +++ b/code/AssetLib/FBX/FBXExporter.cpp @@ -1089,6 +1089,8 @@ void FBXExporter::WriteObjects () bool bJoinIdenticalVertices = mProperties->GetPropertyBool("bJoinIdenticalVertices", true); std::vector> vVertexIndice;//save vertex_indices as it is needed later + const auto bTransparencyFactorReferencedToOpacity = mProperties->GetPropertyBool(AI_CONFIG_EXPORT_FBX_TRANSPARENCY_FACTOR_REFER_TO_OPACITY, false); + // geometry (aiMesh) mesh_uids.clear(); indent = 1; @@ -1445,13 +1447,21 @@ void FBXExporter::WriteObjects () // "TransparentColor" / "TransparencyFactor"... // thanks FBX, for your insightful interpretation of consistency p.AddP70colorA("TransparentColor", c.r, c.g, c.b); - // TransparencyFactor defaults to 0.0, so set it to 1.0. - // note: Maya always sets this to 1.0, - // so we can't use it sensibly as "Opacity". - // In stead we rely on the legacy "Opacity" value, below. - // Blender also relies on "Opacity" not "TransparencyFactor", - // probably for a similar reason. - p.AddP70numberA("TransparencyFactor", 1.0); + + if (!bTransparencyFactorReferencedToOpacity) { + // TransparencyFactor defaults to 0.0, so set it to 1.0. + // note: Maya always sets this to 1.0, + // so we can't use it sensibly as "Opacity". + // In stead we rely on the legacy "Opacity" value, below. + // Blender also relies on "Opacity" not "TransparencyFactor", + // probably for a similar reason. + p.AddP70numberA("TransparencyFactor", 1.0); + } + } + if (bTransparencyFactorReferencedToOpacity) { + if (m->Get(AI_MATKEY_OPACITY, f) == aiReturn_SUCCESS) { + p.AddP70numberA("TransparencyFactor", 1.0 - f); + } } if (m->Get(AI_MATKEY_COLOR_REFLECTIVE, c) == aiReturn_SUCCESS) { p.AddP70colorA("ReflectionColor", c.r, c.g, c.b); diff --git a/include/assimp/config.h.in b/include/assimp/config.h.in index 67fc988be..897eecb19 100644 --- a/include/assimp/config.h.in +++ b/include/assimp/config.h.in @@ -1113,6 +1113,16 @@ enum aiComponent #define AI_CONFIG_EXPORT_GLTF_UNLIMITED_SKINNING_BONES_PER_VERTEX \ "USE_UNLIMITED_BONES_PER VERTEX" +/** @brief Specifies whether to write the value referenced to opacity in TransparencyFactor of each material. + * + * When this flag is not defined, the TransparencyFactor value of each meterial is 1.0. + * By enabling this flag, the value is 1.0 - opacity; + + * Property type: Bool. Default value: false. + */ +#define AI_CONFIG_EXPORT_FBX_TRANSPARENCY_FACTOR_REFER_TO_OPACITY \ + "EXPORT_FBX_TRANSPARENCY_FACTOR_REFER_TO_OPACITY" + /** * @brief Specifies the blob name, assimp uses for exporting. *