assimp/code/PostProcessing/LimitBoneWeightsProcess.cpp

187 lines
6.9 KiB
C++

/*
Open Asset Import Library (assimp)
----------------------------------------------------------------------
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All rights reserved.
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following disclaimer.
* Redistributions in binary form must reproduce the above
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following disclaimer in the documentation and/or other
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* Neither the name of the assimp team, nor the names of its
contributors may be used to endorse or promote products
derived from this software without specific prior
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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---------------------------------------------------------------------- */
#include "LimitBoneWeightsProcess.h"
#include <assimp/SmallVector.h>
#include <assimp/StringUtils.h>
#include <assimp/postprocess.h>
#include <assimp/DefaultLogger.hpp>
#include <assimp/scene.h>
#include <stdio.h>
namespace Assimp {
// Make sure this value is set.
#ifndef AI_LMW_MAX_WEIGHTS
# define AI_LMW_MAX_WEIGHTS 16
#endif
// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
LimitBoneWeightsProcess::LimitBoneWeightsProcess() :
mMaxWeights(AI_LMW_MAX_WEIGHTS), mRemoveEmptyBones(true) {
// empty
}
// ------------------------------------------------------------------------------------------------
// Returns whether the processing step is present in the given flag field.
bool LimitBoneWeightsProcess::IsActive( unsigned int pFlags) const {
return (pFlags & aiProcess_LimitBoneWeights) != 0;
}
// ------------------------------------------------------------------------------------------------
// Executes the post processing step on the given imported data.
void LimitBoneWeightsProcess::Execute( aiScene* pScene) {
ai_assert(pScene != nullptr);
ASSIMP_LOG_DEBUG("LimitBoneWeightsProcess begin");
for (unsigned int m = 0; m < pScene->mNumMeshes; ++m) {
ProcessMesh(pScene->mMeshes[m]);
}
ASSIMP_LOG_DEBUG("LimitBoneWeightsProcess end");
}
// ------------------------------------------------------------------------------------------------
// Executes the post processing step on the given imported data.
void LimitBoneWeightsProcess::SetupProperties(const Importer* pImp) {
this->mMaxWeights = pImp->GetPropertyInteger(AI_CONFIG_PP_LBW_MAX_WEIGHTS,AI_LMW_MAX_WEIGHTS);
this->mRemoveEmptyBones = pImp->GetPropertyInteger(AI_CONFIG_IMPORT_REMOVE_EMPTY_BONES, 1) != 0;
}
// ------------------------------------------------------------------------------------------------
static unsigned int removeEmptyBones(aiMesh *pMesh) {
ai_assert(pMesh != nullptr);
unsigned int writeBone = 0;
for (unsigned int readBone = 0; readBone< pMesh->mNumBones; ++readBone) {
aiBone* bone = pMesh->mBones[readBone];
if (bone->mNumWeights > 0) {
pMesh->mBones[writeBone++] = bone;
} else {
delete bone;
}
}
return writeBone;
}
// ------------------------------------------------------------------------------------------------
// Unites identical vertices in the given mesh
void LimitBoneWeightsProcess::ProcessMesh(aiMesh* pMesh) {
if (!pMesh->HasBones())
return;
// collect all bone weights per vertex
typedef SmallVector<Weight,8> VertexWeightArray;
typedef std::vector<VertexWeightArray> WeightsPerVertex;
WeightsPerVertex vertexWeights(pMesh->mNumVertices);
size_t maxVertexWeights = 0;
for (unsigned int b = 0; b < pMesh->mNumBones; ++b) {
const aiBone* bone = pMesh->mBones[b];
for (unsigned int w = 0; w < bone->mNumWeights; ++w) {
const aiVertexWeight& vw = bone->mWeights[w];
if (vertexWeights.size() <= vw.mVertexId)
continue;
vertexWeights[vw.mVertexId].push_back(Weight(b, vw.mWeight));
maxVertexWeights = std::max(maxVertexWeights, vertexWeights[vw.mVertexId].size());
}
}
if (maxVertexWeights <= mMaxWeights)
return;
unsigned int removed = 0, old_bones = pMesh->mNumBones;
// now cut the weight count if it exceeds the maximum
for (WeightsPerVertex::iterator vit = vertexWeights.begin(); vit != vertexWeights.end(); ++vit) {
if (vit->size() <= mMaxWeights)
continue;
// more than the defined maximum -> first sort by weight in descending order. That's
// why we defined the < operator in such a weird way.
std::sort(vit->begin(), vit->end());
// now kill everything beyond the maximum count
unsigned int m = static_cast<unsigned int>(vit->size());
vit->resize(mMaxWeights);
removed += static_cast<unsigned int>(m - vit->size());
// and renormalize the weights
float sum = 0.0f;
for(const Weight* it = vit->begin(); it != vit->end(); ++it) {
sum += it->mWeight;
}
if (0.0f != sum) {
const float invSum = 1.0f / sum;
for(Weight* it = vit->begin(); it != vit->end(); ++it) {
it->mWeight *= invSum;
}
}
}
// clear weight count for all bone
for (unsigned int a = 0; a < pMesh->mNumBones; ++a) {
pMesh->mBones[a]->mNumWeights = 0;
}
// rebuild the vertex weight array for all bones
for (unsigned int a = 0; a < vertexWeights.size(); ++a) {
const VertexWeightArray& vw = vertexWeights[a];
for (const Weight* it = vw.begin(); it != vw.end(); ++it) {
aiBone* bone = pMesh->mBones[it->mBone];
bone->mWeights[bone->mNumWeights++] = aiVertexWeight(a, it->mWeight);
}
}
// remove empty bones
if (mRemoveEmptyBones) {
pMesh->mNumBones = removeEmptyBones(pMesh);
}
if (!DefaultLogger::isNullLogger()) {
ASSIMP_LOG_INFO("Removed ", removed, " weights. Input bones: ", old_bones, ". Output bones: ", pMesh->mNumBones);
}
}
} // namespace Assimp