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Extension of data export to GLB/GLTF format

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Allows to export unlimited (more than 4) bones per vertex
Use JOINTS_1,2,.. and WEIGHTS_1,2,...
Added AI_CONFIG_EXPORT_GLTF_UNLIMITED_SKINNING_BONES_PER_VERTEX flag
This commit is contained in:
fvbj
2023-10-08 14:43:53 +00:00
committed by Kim Kulling
parent 5b8cfa920b
commit 8fcc65a8af
4 changed files with 251 additions and 72 deletions
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code/AssetLib/glTF2/glTF2Exporter.cpp
+99 -72
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@@ -172,22 +172,6 @@ static void IdentityMatrix4(mat4 &o) {
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>
void SetAccessorRange(Ref<Accessor> acc, void *data, size_t count,
unsigned int numCompsIn, unsigned int numCompsOut) {
@@ -1009,23 +993,29 @@ Ref<Node> FindSkeletonRootJoint(Ref<Skin> &skinRef) {
return parentNodeRef;
}
struct boneIndexWeightPair {
unsigned int indexJoint;
float weight;
bool operator()(boneIndexWeightPair &a, boneIndexWeightPair &b) {
return a.weight > b.weight;
}
};
void ExportSkin(Asset &mAsset, const aiMesh *aimesh, Ref<Mesh> &meshRef, Ref<Buffer> &bufferRef, Ref<Skin> &skinRef,
std::vector<aiMatrix4x4> &inverseBindMatricesData) {
std::vector<aiMatrix4x4> &inverseBindMatricesData, bool unlimitedBonesPerVertex) {
if (aimesh->mNumBones < 1) {
return;
}
// Store the vertex joint and weight data.
const size_t NumVerts(aimesh->mNumVertices);
vec4 *vertexJointData = new vec4[NumVerts];
vec4 *vertexWeightData = new vec4[NumVerts];
int *jointsPerVertex = new int[NumVerts];
std::vector<std::vector<boneIndexWeightPair>> allVerticesPairs;
int maxJointsPerVertex = 0;
for (size_t i = 0; i < NumVerts; ++i) {
jointsPerVertex[i] = 0;
for (size_t j = 0; j < 4; ++j) {
vertexJointData[i][j] = 0;
vertexWeightData[i][j] = 0;
}
std::vector<boneIndexWeightPair> vertexPair;
allVerticesPairs.push_back(vertexPair);
}
for (unsigned int idx_bone = 0; idx_bone < aimesh->mNumBones; ++idx_bone) {
@@ -1055,61 +1045,88 @@ void ExportSkin(Asset &mAsset, const aiMesh *aimesh, Ref<Mesh> &meshRef, Ref<Buf
jointNamesIndex = static_cast<unsigned int>(inverseBindMatricesData.size() - 1);
}
// aib->mWeights =====> vertexWeightData
for (unsigned int idx_weights = 0; idx_weights < aib->mNumWeights; ++idx_weights) {
// aib->mWeights =====> temp pairs data
for (unsigned int idx_weights = 0; idx_weights < aib->mNumWeights;
++idx_weights) {
unsigned int vertexId = aib->mWeights[idx_weights].mVertexId;
float vertWeight = aib->mWeights[idx_weights].mWeight;
// A vertex can only have at most four joint weights, which ideally sum up to 1
if (IsBoneWeightFitted(vertexWeightData[vertexId])) {
continue;
}
if (jointsPerVertex[vertexId] > 3) {
int boneIndexFitted = FitBoneWeight(vertexWeightData[vertexId], vertWeight);
if (boneIndexFitted != -1) {
vertexJointData[vertexId][boneIndexFitted] = static_cast<float>(jointNamesIndex);
}
} else {
vertexJointData[vertexId][jointsPerVertex[vertexId]] = static_cast<float>(jointNamesIndex);
vertexWeightData[vertexId][jointsPerVertex[vertexId]] = vertWeight;
jointsPerVertex[vertexId] += 1;
}
allVerticesPairs[vertexId].push_back({jointNamesIndex, vertWeight});
jointsPerVertex[vertexId] += 1;
maxJointsPerVertex =
std::max(maxJointsPerVertex, jointsPerVertex[vertexId]);
}
} // End: for-loop mNumMeshes
Mesh::Primitive &p = meshRef->primitives.back();
Ref<Accessor> vertexJointAccessor = ExportData(mAsset, skinRef->id, bufferRef, aimesh->mNumVertices,
vertexJointData, AttribType::VEC4, AttribType::VEC4, ComponentType_FLOAT);
if (vertexJointAccessor) {
size_t offset = vertexJointAccessor->bufferView->byteOffset;
size_t bytesLen = vertexJointAccessor->bufferView->byteLength;
unsigned int s_bytesPerComp = ComponentTypeSize(ComponentType_UNSIGNED_SHORT);
unsigned int bytesPerComp = ComponentTypeSize(vertexJointAccessor->componentType);
size_t s_bytesLen = bytesLen * s_bytesPerComp / bytesPerComp;
Ref<Buffer> buf = vertexJointAccessor->bufferView->buffer;
uint8_t *arrys = new uint8_t[bytesLen];
unsigned int i = 0;
for (unsigned int j = 0; j < bytesLen; j += bytesPerComp) {
size_t len_p = offset + j;
float f_value = *(float *)&buf->GetPointer()[len_p];
unsigned short c = static_cast<unsigned short>(f_value);
memcpy(&arrys[i * s_bytesPerComp], &c, s_bytesPerComp);
++i;
}
buf->ReplaceData_joint(offset, bytesLen, arrys, bytesLen);
vertexJointAccessor->componentType = ComponentType_UNSIGNED_SHORT;
vertexJointAccessor->bufferView->byteLength = s_bytesLen;
p.attributes.joint.push_back(vertexJointAccessor);
delete[] arrys;
if (!unlimitedBonesPerVertex){
// skinning limited only for 4 bones per vertex, default
maxJointsPerVertex = 4;
}
Ref<Accessor> vertexWeightAccessor = ExportData(mAsset, skinRef->id, bufferRef, aimesh->mNumVertices,
vertexWeightData, AttribType::VEC4, AttribType::VEC4, ComponentType_FLOAT);
if (vertexWeightAccessor) {
p.attributes.weight.push_back(vertexWeightAccessor);
// temp pairs data =====> vertexWeightData
size_t numGroups = (maxJointsPerVertex - 1) / 4 + 1;
vec4 *vertexJointData = new vec4[NumVerts * numGroups];
vec4 *vertexWeightData = new vec4[NumVerts * numGroups];
for (size_t indexVertex = 0; indexVertex < NumVerts; ++indexVertex) {
// order pairs by weight for each vertex
std::sort(allVerticesPairs[indexVertex].begin(),
allVerticesPairs[indexVertex].end(),
boneIndexWeightPair());
for (size_t indexGroup = 0; indexGroup < numGroups; ++indexGroup) {
for (size_t indexJoint = 0; indexJoint < 4; ++indexJoint) {
size_t indexBone = indexGroup * 4 + indexJoint;
size_t indexData = indexVertex + NumVerts * indexGroup;
if (indexBone >= allVerticesPairs[indexVertex].size()) {
vertexJointData[indexData][indexJoint] = 0.f;
vertexWeightData[indexData][indexJoint] = 0.f;
} else {
vertexJointData[indexData][indexJoint] =
static_cast<float>(
allVerticesPairs[indexVertex][indexBone].indexJoint);
vertexWeightData[indexData][indexJoint] =
allVerticesPairs[indexVertex][indexBone].weight;
}
}
}
}
for (size_t idx_group = 0; idx_group < numGroups; ++idx_group) {
Mesh::Primitive &p = meshRef->primitives.back();
Ref<Accessor> vertexJointAccessor = ExportData(
mAsset, skinRef->id, bufferRef, aimesh->mNumVertices,
vertexJointData + idx_group * NumVerts,
AttribType::VEC4, AttribType::VEC4, ComponentType_FLOAT);
if (vertexJointAccessor) {
size_t offset = vertexJointAccessor->bufferView->byteOffset;
size_t bytesLen = vertexJointAccessor->bufferView->byteLength;
unsigned int s_bytesPerComp =
ComponentTypeSize(ComponentType_UNSIGNED_SHORT);
unsigned int bytesPerComp =
ComponentTypeSize(vertexJointAccessor->componentType);
size_t s_bytesLen = bytesLen * s_bytesPerComp / bytesPerComp;
Ref<Buffer> buf = vertexJointAccessor->bufferView->buffer;
uint8_t *arrys = new uint8_t[bytesLen];
unsigned int i = 0;
for (unsigned int j = 0; j < bytesLen; j += bytesPerComp) {
size_t len_p = offset + j;
float f_value = *(float *)&buf->GetPointer()[len_p];
unsigned short c = static_cast<unsigned short>(f_value);
memcpy(&arrys[i * s_bytesPerComp], &c, s_bytesPerComp);
++i;
}
buf->ReplaceData_joint(offset, bytesLen, arrys, bytesLen);
vertexJointAccessor->componentType = ComponentType_UNSIGNED_SHORT;
vertexJointAccessor->bufferView->byteLength = s_bytesLen;
p.attributes.joint.push_back(vertexJointAccessor);
delete[] arrys;
}
Ref<Accessor> vertexWeightAccessor = ExportData(
mAsset, skinRef->id, bufferRef, aimesh->mNumVertices,
vertexWeightData + idx_group * NumVerts,
AttribType::VEC4, AttribType::VEC4, ComponentType_FLOAT);
if (vertexWeightAccessor) {
p.attributes.weight.push_back(vertexWeightAccessor);
}
}
delete[] jointsPerVertex;
delete[] vertexWeightData;
@@ -1247,9 +1264,19 @@ void glTF2Exporter::ExportMeshes() {
break;
}
// /*************** Skins ****************/
// if (aim->HasBones()) {
// ExportSkin(*mAsset, aim, m, b, skinRef, inverseBindMatricesData);
// }
/*************** Skins ****************/
if (aim->HasBones()) {
ExportSkin(*mAsset, aim, m, b, skinRef, inverseBindMatricesData);
bool unlimitedBonesPerVertex =
this->mProperties->HasPropertyBool(
AI_CONFIG_EXPORT_GLTF_UNLIMITED_SKINNING_BONES_PER_VERTEX) &&
this->mProperties->GetPropertyBool(
AI_CONFIG_EXPORT_GLTF_UNLIMITED_SKINNING_BONES_PER_VERTEX);
ExportSkin(*mAsset, aim, m, b, skinRef, inverseBindMatricesData,
unlimitedBonesPerVertex);
}
/*************** Targets for blendshapes ****************/