Merge branch 'master' into ms3d-fixes

pull/3749/head
Kim Kulling 2021-04-11 19:12:06 +02:00 committed by GitHub
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37
INSTALL
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@ -8,43 +8,10 @@ Getting the documentation
------------------------------
A regularly-updated copy is available at
http://assimp.sourceforge.net/lib_html/index.html
A CHM file is included in the SVN repos: ./doc/AssimpDoc_Html/AssimpDoc.chm.
To build the doxygen documentation on your own, follow these steps:
a) download & install latest doxygen
b) make sure doxygen is in the executable search path
c) navigate to ./doc
d) and run 'doxygen'
Open the generated HTML (AssimpDoc_Html/index.html) in the browser of your choice.
Windows only: To generate the CHM doc, install 'Microsoft HTML Workshop'
and configure the path to it in the DOXYFILE first.
https://assimp-docs.readthedocs.io/en/latest/
------------------------------
Building Assimp
------------------------------
More detailed build instructions can be found in the documentation,
this section is just for the inpatient among you.
CMake is the preferred build system for Assimp. The minimum required version
is 2.6. If you don't have it yet, downloads for CMake can be found on
http://www.cmake.org/.
For Unix:
1. mkdir build && cd build
2. cmake .. -G 'Unix Makefiles'
3. make -j4
For Windows:
1. Open a command prompt
2. mkdir build
3. cd build
4. cmake ..
5. cmake --build .
For iOS:
Just check the following project, which deploys a compiler toolchain for different iOS-versions: https://github.com/assimp/assimp/tree/master/port/iOS
Just check the build-instaructions which you can find here: https://github.com/assimp/assimp/blob/master/Build.md

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@ -158,6 +158,9 @@ void HMPImporter::InternReadFile(const std::string &pFile,
szBuffer[3] = ((char *)&iMagic)[3];
szBuffer[4] = '\0';
delete[] mBuffer;
mBuffer = nullptr;
// We're definitely unable to load this file
throw DeadlyImportError("Unknown HMP subformat ", pFile,
". Magic word (", szBuffer, ") is not known");

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@ -813,6 +813,11 @@ struct Mesh : public Object {
AccessorList position, normal, tangent;
};
std::vector<Target> targets;
// extension: FB_ngon_encoding
bool ngonEncoded;
Primitive(): ngonEncoded(false) {}
};
std::vector<Primitive> primitives;
@ -1108,6 +1113,7 @@ public:
bool KHR_materials_clearcoat;
bool KHR_materials_transmission;
bool KHR_draco_mesh_compression;
bool FB_ngon_encoding;
} extensionsUsed;
//! Keeps info about the required extensions

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@ -507,6 +507,20 @@ namespace glTF2 {
Mesh::Primitive& p = m.primitives[i];
Value prim;
prim.SetObject();
// Extensions
if (p.ngonEncoded)
{
Value exts;
exts.SetObject();
Value FB_ngon_encoding;
FB_ngon_encoding.SetObject();
exts.AddMember(StringRef("FB_ngon_encoding"), FB_ngon_encoding, w.mAl);
prim.AddMember("extensions", exts, w.mAl);
}
{
prim.AddMember("mode", Value(int(p.mode)).Move(), w.mAl);
@ -874,6 +888,10 @@ namespace glTF2 {
if (this->mAsset.extensionsUsed.KHR_materials_transmission) {
exts.PushBack(StringRef("KHR_materials_transmission"), mAl);
}
if (this->mAsset.extensionsUsed.FB_ngon_encoding) {
exts.PushBack(StringRef("FB_ngon_encoding"), mAl);
}
}
if (!exts.Empty())

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@ -97,6 +97,9 @@ glTF2Exporter::glTF2Exporter(const char* filename, IOSystem* pIOSystem, const ai
mAsset.reset( new Asset( pIOSystem ) );
// Always on as our triangulation process is aware of this type of encoding
mAsset->extensionsUsed.FB_ngon_encoding = true;
if (isBinary) {
mAsset->SetAsBinary();
}
@ -955,6 +958,7 @@ void glTF2Exporter::ExportMeshes()
m->name = name;
p.material = mAsset->materials.Get(aim->mMaterialIndex);
p.ngonEncoded = (aim->mPrimitiveTypes & aiPrimitiveType_NGONEncodingFlag) != 0;
/******************* Vertices ********************/
Ref<Accessor> v = ExportData(*mAsset, meshId, b, aim->mNumVertices, aim->mVertices, AttribType::VEC3, AttribType::VEC3, ComponentType_FLOAT, BufferViewTarget_ARRAY_BUFFER);

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@ -76,6 +76,87 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
using namespace Assimp;
namespace {
/**
* @brief Helper struct used to simplify NGON encoding functions.
*/
struct NGONEncoder {
NGONEncoder() : mLastNGONFirstIndex((unsigned int)-1) {}
/**
* @brief Encode the current triangle, and make sure it is recognized as a triangle.
*
* This method will rotate indices in tri if needed in order to avoid tri to be considered
* part of the previous ngon. This method is to be used whenever you want to emit a real triangle,
* and make sure it is seen as a triangle.
*
* @param tri Triangle to encode.
*/
void ngonEncodeTriangle(aiFace * tri) {
ai_assert(tri->mNumIndices == 3);
// Rotate indices in new triangle to avoid ngon encoding false ngons
// Otherwise, the new triangle would be considered part of the previous NGON.
if (isConsideredSameAsLastNgon(tri)) {
std::swap(tri->mIndices[0], tri->mIndices[2]);
std::swap(tri->mIndices[1], tri->mIndices[2]);
}
mLastNGONFirstIndex = tri->mIndices[0];
}
/**
* @brief Encode a quad (2 triangles) in ngon encoding, and make sure they are seen as a single ngon.
*
* @param tri1 First quad triangle
* @param tri2 Second quad triangle
*
* @pre Triangles must be properly fanned from the most appropriate vertex.
*/
void ngonEncodeQuad(aiFace *tri1, aiFace *tri2) {
ai_assert(tri1->mNumIndices == 3);
ai_assert(tri2->mNumIndices == 3);
ai_assert(tri1->mIndices[0] == tri2->mIndices[0]);
// If the selected fanning vertex is the same as the previously
// emitted ngon, we use the opposite vertex which also happens to work
// for tri-fanning a concave quad.
// ref: https://github.com/assimp/assimp/pull/3695#issuecomment-805999760
if (isConsideredSameAsLastNgon(tri1)) {
// Right-rotate indices for tri1 (index 2 becomes the new fanning vertex)
std::swap(tri1->mIndices[0], tri1->mIndices[2]);
std::swap(tri1->mIndices[1], tri1->mIndices[2]);
// Left-rotate indices for tri2 (index 2 becomes the new fanning vertex)
std::swap(tri2->mIndices[1], tri2->mIndices[2]);
std::swap(tri2->mIndices[0], tri2->mIndices[2]);
ai_assert(tri1->mIndices[0] == tri2->mIndices[0]);
}
mLastNGONFirstIndex = tri1->mIndices[0];
}
/**
* @brief Check whether this triangle would be considered part of the lastly emitted ngon or not.
*
* @param tri Current triangle.
* @return true If used as is, this triangle will be part of last ngon.
* @return false If used as is, this triangle is not considered part of the last ngon.
*/
bool isConsideredSameAsLastNgon(const aiFace * tri) const {
ai_assert(tri->mNumIndices == 3);
return tri->mIndices[0] == mLastNGONFirstIndex;
}
private:
unsigned int mLastNGONFirstIndex;
};
}
// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
TriangulateProcess::TriangulateProcess()
@ -175,10 +256,15 @@ bool TriangulateProcess::TriangulateMesh( aiMesh* pMesh)
pMesh->mPrimitiveTypes |= aiPrimitiveType_TRIANGLE;
pMesh->mPrimitiveTypes &= ~aiPrimitiveType_POLYGON;
// The mesh becomes NGON encoded now, during the triangulation process.
pMesh->mPrimitiveTypes |= aiPrimitiveType_NGONEncodingFlag;
aiFace* out = new aiFace[numOut](), *curOut = out;
std::vector<aiVector3D> temp_verts3d(max_out+2); /* temporary storage for vertices */
std::vector<aiVector2D> temp_verts(max_out+2);
NGONEncoder ngonEncoder;
// Apply vertex colors to represent the face winding?
#ifdef AI_BUILD_TRIANGULATE_COLOR_FACE_WINDING
if (!pMesh->mColors[0])
@ -220,8 +306,11 @@ bool TriangulateProcess::TriangulateMesh( aiMesh* pMesh)
aiFace& nface = *curOut++;
nface.mNumIndices = face.mNumIndices;
nface.mIndices = face.mIndices;
face.mIndices = nullptr;
// points and lines don't require ngon encoding (and are not supported either!)
if (nface.mNumIndices == 3) ngonEncoder.ngonEncodeTriangle(&nface);
continue;
}
// optimized code for quadrilaterals
@ -274,6 +363,9 @@ bool TriangulateProcess::TriangulateMesh( aiMesh* pMesh)
// prevent double deletion of the indices field
face.mIndices = nullptr;
ngonEncoder.ngonEncodeQuad(&nface, &sface);
continue;
}
else
@ -284,7 +376,7 @@ bool TriangulateProcess::TriangulateMesh( aiMesh* pMesh)
// modeling suite to make extensive use of highly concave, monster polygons ...
// so we need to apply the full 'ear cutting' algorithm to get it right.
// RERQUIREMENT: polygon is expected to be simple and *nearly* planar.
// REQUIREMENT: polygon is expected to be simple and *nearly* planar.
// We project it onto a plane to get a 2d triangle.
// Collect all vertices of of the polygon.
@ -508,6 +600,11 @@ bool TriangulateProcess::TriangulateMesh( aiMesh* pMesh)
i[0] = idx[i[0]];
i[1] = idx[i[1]];
i[2] = idx[i[2]];
// IMPROVEMENT: Polygons are not supported yet by this ngon encoding + triangulation step.
// So we encode polygons as regular triangles. No way to reconstruct the original
// polygon in this case.
ngonEncoder.ngonEncodeTriangle(f);
++f;
}

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@ -97,7 +97,7 @@ inline T getEpsilon() {
/// @brief Will return the constant PI for the requested type.
/// @return Pi
template<class T>
inline T PI() {
inline T aiPi() {
return static_cast<T>(3.14159265358979323846);
}

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@ -398,6 +398,24 @@ enum aiPrimitiveType {
*/
aiPrimitiveType_POLYGON = 0x8,
/**
* A flag to determine whether this triangles only mesh is NGON encoded.
*
* NGON encoding is a special encoding that tells whether 2 or more consecutive triangles
* should be considered as a triangle fan. This is identified by looking at the first vertex index.
* 2 consecutive triangles with the same 1st vertex index are part of the same
* NGON.
*
* At the moment, only quads (concave or convex) are supported, meaning that polygons are 'seen' as
* triangles, as usual after a triangulation pass.
*
* To get an NGON encoded mesh, please use the aiProcess_Triangulate post process.
*
* @see aiProcess_Triangulate
* @link https://github.com/KhronosGroup/glTF/pull/1620
*/
aiPrimitiveType_NGONEncodingFlag = 0x10,
/** This value is not used. It is just here to force the
* compiler to map this enum to a 32 Bit integer.
*/

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@ -57,7 +57,7 @@ protected:
aiMatrix4x4 get_predetermined_transformation_matrix_for_decomposition() const {
aiMatrix4x4 t, r;
aiMatrix4x4::Translation(aiVector3D(14,-25,-8), t);
aiMatrix4x4::Rotation(Math::PI<float>() / 4.0f, aiVector3D(1).Normalize(), r);
aiMatrix4x4::Rotation(Math::aiPi<float>() / 4.0f, aiVector3D(1).Normalize(), r);
return t * r;
}

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@ -59,7 +59,7 @@ TEST_F(AssimpAPITest_aiQuaternion, aiCreateQuaternionFromMatrixTest) {
// to prevent running into division by zero.
aiMatrix3x3 m, r;
aiMatrix3x3::Translation(aiVector2D(14,-25), m);
aiMatrix3x3::RotationZ(Math::PI<float>() / 4.0f, r);
aiMatrix3x3::RotationZ(Math::aiPi<float>() / 4.0f, r);
m = m * r;
result_cpp = aiQuaternion(m);
@ -127,8 +127,8 @@ TEST_F(AssimpAPITest_aiQuaternion, aiQuaternionInterpolateTest) {
// Use predetermined quaternions to prevent division by zero
// during slerp calculations.
const float INTERPOLATION(0.5f);
const auto q1 = aiQuaternion(aiVector3D(-1,1,1).Normalize(), Math::PI<float>() / 4.0f);
const auto q2 = aiQuaternion(aiVector3D(1,2,1).Normalize(), Math::PI<float>() / 2.0f);
const auto q1 = aiQuaternion(aiVector3D(-1,1,1).Normalize(), Math::aiPi<float>() / 4.0f);
const auto q2 = aiQuaternion(aiVector3D(1,2,1).Normalize(), Math::aiPi<float>() / 2.0f);
aiQuaternion::Interpolate(result_cpp, q1, q2, INTERPOLATION);
aiQuaternionInterpolate(&result_c, &q1, &q2, INTERPOLATION);
EXPECT_EQ(result_cpp, result_c);

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@ -51,6 +51,6 @@ const float AssimpMathTest::Epsilon = Math::getEpsilon<float>();
RandomUniformFloatGenerator AssimpMathTest::RandNonZero(1.0f, 100.0f);
// Initialize with an interval of [-PI,PI] inclusively.
RandomUniformFloatGenerator AssimpMathTest::RandPI(-Math::PI<float>(), Math::PI<float>());
RandomUniformFloatGenerator AssimpMathTest::RandPI(-Math::aiPi<float>(), Math::aiPi<float>());
}