assimp/include/assimp/SmoothingGroups.inl

142 lines
5.1 KiB
C++

/*
---------------------------------------------------------------------------
Open Asset Import Library (assimp)
---------------------------------------------------------------------------
Copyright (c) 2006-2021, assimp team
All rights reserved.
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with or without modification, are permitted provided that the following
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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
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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
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*/
/** @file Generation of normal vectors basing on smoothing groups */
#pragma once
#ifndef AI_SMOOTHINGGROUPS_INL_INCLUDED
#define AI_SMOOTHINGGROUPS_INL_INCLUDED
#ifdef __GNUC__
# pragma GCC system_header
#endif
#include <assimp/SGSpatialSort.h>
#include <algorithm>
using namespace Assimp;
// ------------------------------------------------------------------------------------------------
template <class T>
void ComputeNormalsWithSmoothingsGroups(MeshWithSmoothingGroups<T>& sMesh)
{
// First generate face normals
sMesh.mNormals.resize(sMesh.mPositions.size(),aiVector3D());
for( unsigned int a = 0; a < sMesh.mFaces.size(); a++)
{
T& face = sMesh.mFaces[a];
aiVector3D* pV1 = &sMesh.mPositions[face.mIndices[0]];
aiVector3D* pV2 = &sMesh.mPositions[face.mIndices[1]];
aiVector3D* pV3 = &sMesh.mPositions[face.mIndices[2]];
aiVector3D pDelta1 = *pV2 - *pV1;
aiVector3D pDelta2 = *pV3 - *pV1;
aiVector3D vNor = pDelta1 ^ pDelta2;
for (unsigned int c = 0; c < 3;++c)
sMesh.mNormals[face.mIndices[c]] = vNor;
}
// calculate the position bounds so we have a reliable epsilon to check position differences against
aiVector3D minVec( 1e10f, 1e10f, 1e10f), maxVec( -1e10f, -1e10f, -1e10f);
for( unsigned int a = 0; a < sMesh.mPositions.size(); a++)
{
minVec.x = std::min( minVec.x, sMesh.mPositions[a].x);
minVec.y = std::min( minVec.y, sMesh.mPositions[a].y);
minVec.z = std::min( minVec.z, sMesh.mPositions[a].z);
maxVec.x = std::max( maxVec.x, sMesh.mPositions[a].x);
maxVec.y = std::max( maxVec.y, sMesh.mPositions[a].y);
maxVec.z = std::max( maxVec.z, sMesh.mPositions[a].z);
}
const float posEpsilon = (maxVec - minVec).Length() * 1e-5f;
std::vector<aiVector3D> avNormals;
avNormals.resize(sMesh.mNormals.size());
// now generate the spatial sort tree
SGSpatialSort sSort;
for( typename std::vector<T>::iterator i = sMesh.mFaces.begin();
i != sMesh.mFaces.end();++i)
{
for (unsigned int c = 0; c < 3;++c)
sSort.Add(sMesh.mPositions[(*i).mIndices[c]],(*i).mIndices[c],(*i).iSmoothGroup);
}
sSort.Prepare();
std::vector<bool> vertexDone(sMesh.mPositions.size(),false);
for( typename std::vector<T>::iterator i = sMesh.mFaces.begin();
i != sMesh.mFaces.end();++i)
{
std::vector<unsigned int> poResult;
for (unsigned int c = 0; c < 3;++c)
{
unsigned int idx = (*i).mIndices[c];
if (vertexDone[idx])continue;
sSort.FindPositions(sMesh.mPositions[idx],(*i).iSmoothGroup,
posEpsilon,poResult);
aiVector3D vNormals;
for (std::vector<unsigned int>::const_iterator
a = poResult.begin();
a != poResult.end();++a)
{
vNormals += sMesh.mNormals[(*a)];
}
vNormals.NormalizeSafe();
// write back into all affected normals
for (std::vector<unsigned int>::const_iterator
a = poResult.begin();
a != poResult.end();++a)
{
idx = *a;
avNormals [idx] = vNormals;
vertexDone[idx] = true;
}
}
}
sMesh.mNormals = avNormals;
}
#endif // !! AI_SMOOTHINGGROUPS_INL_INCLUDED