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Fix glTF2 skinning bone weight exporting issue

pull/4174/head
freizhang 2021-11-13 12:07:29 +08:00
parent 6e6807ee6c
commit b9937994ca
1 changed files with 28 additions and 6 deletions
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34
code/AssetLib/glTF2/glTF2Exporter.cpp
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@ -174,6 +174,22 @@ static void IdentityMatrix4(mat4 &o) {
o[15] = 1; o[15] = 1;
} }
static bool IsBoneWeightFitted(vec4 &weight) {
return weight[0] + weight[1] + weight[2] + weight[3] >= 1.f;
}
static int FitBoneWeight(vec4 &weight, float value) {
int i = 0;
for (; i < 4; ++i) {
if (weight[i] < value) {
weight[i] = value;
return i;
}
}
return -1;
}
template <typename T> template <typename T>
void SetAccessorRange(Ref<Accessor> acc, void *data, size_t count, void SetAccessorRange(Ref<Accessor> acc, void *data, size_t count,
unsigned int numCompsIn, unsigned int numCompsOut) { unsigned int numCompsIn, unsigned int numCompsOut) {
@ -950,15 +966,21 @@ void ExportSkin(Asset &mAsset, const aiMesh *aimesh, Ref<Mesh> &meshRef, Ref<Buf
unsigned int vertexId = aib->mWeights[idx_weights].mVertexId; unsigned int vertexId = aib->mWeights[idx_weights].mVertexId;
float vertWeight = aib->mWeights[idx_weights].mWeight; float vertWeight = aib->mWeights[idx_weights].mWeight;
// A vertex can only have at most four joint weights. Ignore all others. // A vertex can only have at most four joint weights, which ideally sum up to 1
if (jointsPerVertex[vertexId] > 3) { if (IsBoneWeightFitted(vertexWeightData[vertexId])) {
continue; continue;
} }
if (jointsPerVertex[vertexId] > 3) {
int boneIndexFitted = FitBoneWeight(vertexWeightData[vertexId], vertWeight);
if (boneIndexFitted) {
vertexJointData[vertexId][boneIndexFitted] = static_cast<float>(jointNamesIndex);
}
}else {
vertexJointData[vertexId][jointsPerVertex[vertexId]] = static_cast<float>(jointNamesIndex);
vertexWeightData[vertexId][jointsPerVertex[vertexId]] = vertWeight;
vertexJointData[vertexId][jointsPerVertex[vertexId]] = static_cast<float>(jointNamesIndex); jointsPerVertex[vertexId] += 1;
vertexWeightData[vertexId][jointsPerVertex[vertexId]] = vertWeight; }
jointsPerVertex[vertexId] += 1;
} }
} // End: for-loop mNumMeshes } // End: for-loop mNumMeshes