240 lines
9.2 KiB
C++
240 lines
9.2 KiB
C++
/*
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---------------------------------------------------------------------------
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Open Asset Import Library (assimp)
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---------------------------------------------------------------------------
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Copyright (c) 2006-2019, assimp team
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All rights reserved.
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Redistribution and use of this software in source and binary forms,
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with or without modification, are permitted provided that the following
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conditions are met:
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* Redistributions of source code must retain the above
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copyright notice, this list of conditions and the
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following disclaimer.
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* Redistributions in binary form must reproduce the above
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copyright notice, this list of conditions and the
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following disclaimer in the documentation and/or other
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materials provided with the distribution.
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* Neither the name of the assimp team, nor the names of its
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contributors may be used to endorse or promote products
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derived from this software without specific prior
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written permission of the assimp team.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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---------------------------------------------------------------------------
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*/
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/** @file Implementation of the post processing step to generate face
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* normals for all imported faces.
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*/
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// internal headers
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#include "GenVertexNormalsProcess.h"
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#include "ProcessHelper.h"
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#include <assimp/Exceptional.h>
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#include <assimp/qnan.h>
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using namespace Assimp;
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// ------------------------------------------------------------------------------------------------
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// Constructor to be privately used by Importer
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GenVertexNormalsProcess::GenVertexNormalsProcess()
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: configMaxAngle( AI_DEG_TO_RAD( 175.f ) ) {
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// empty
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}
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// ------------------------------------------------------------------------------------------------
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// Destructor, private as well
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GenVertexNormalsProcess::~GenVertexNormalsProcess() {
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// nothing to do here
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}
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// ------------------------------------------------------------------------------------------------
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// Returns whether the processing step is present in the given flag field.
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bool GenVertexNormalsProcess::IsActive( unsigned int pFlags) const
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{
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force_ = (pFlags & aiProcess_ForceGenNormals) != 0;
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return (pFlags & aiProcess_GenSmoothNormals) != 0;
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}
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// ------------------------------------------------------------------------------------------------
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// Executes the post processing step on the given imported data.
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void GenVertexNormalsProcess::SetupProperties(const Importer* pImp)
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{
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// Get the current value of the AI_CONFIG_PP_GSN_MAX_SMOOTHING_ANGLE property
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configMaxAngle = pImp->GetPropertyFloat(AI_CONFIG_PP_GSN_MAX_SMOOTHING_ANGLE,(ai_real)175.0);
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configMaxAngle = AI_DEG_TO_RAD(std::max(std::min(configMaxAngle,(ai_real)175.0),(ai_real)0.0));
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}
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// ------------------------------------------------------------------------------------------------
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// Executes the post processing step on the given imported data.
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void GenVertexNormalsProcess::Execute( aiScene* pScene)
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{
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ASSIMP_LOG_DEBUG("GenVertexNormalsProcess begin");
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if (pScene->mFlags & AI_SCENE_FLAGS_NON_VERBOSE_FORMAT) {
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throw DeadlyImportError("Post-processing order mismatch: expecting pseudo-indexed (\"verbose\") vertices here");
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}
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bool bHas = false;
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for( unsigned int a = 0; a < pScene->mNumMeshes; ++a) {
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if(GenMeshVertexNormals( pScene->mMeshes[a],a))
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bHas = true;
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}
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if (bHas) {
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ASSIMP_LOG_INFO("GenVertexNormalsProcess finished. "
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"Vertex normals have been calculated");
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} else {
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ASSIMP_LOG_DEBUG("GenVertexNormalsProcess finished. "
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"Normals are already there");
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}
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}
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// ------------------------------------------------------------------------------------------------
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// Executes the post processing step on the given imported data.
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bool GenVertexNormalsProcess::GenMeshVertexNormals (aiMesh* pMesh, unsigned int meshIndex)
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{
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if (NULL != pMesh->mNormals) {
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if (force_) delete[] pMesh->mNormals;
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else return false;
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}
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// If the mesh consists of lines and/or points but not of
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// triangles or higher-order polygons the normal vectors
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// are undefined.
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if (!(pMesh->mPrimitiveTypes & (aiPrimitiveType_TRIANGLE | aiPrimitiveType_POLYGON)))
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{
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ASSIMP_LOG_INFO("Normal vectors are undefined for line and point meshes");
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return false;
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}
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// Allocate the array to hold the output normals
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const float qnan = std::numeric_limits<ai_real>::quiet_NaN();
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pMesh->mNormals = new aiVector3D[pMesh->mNumVertices];
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// Compute per-face normals but store them per-vertex
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for( unsigned int a = 0; a < pMesh->mNumFaces; a++)
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{
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const aiFace& face = pMesh->mFaces[a];
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if (face.mNumIndices < 3)
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{
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// either a point or a line -> no normal vector
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for (unsigned int i = 0;i < face.mNumIndices;++i) {
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pMesh->mNormals[face.mIndices[i]] = aiVector3D(qnan);
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}
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continue;
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}
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const aiVector3D* pV1 = &pMesh->mVertices[face.mIndices[0]];
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const aiVector3D* pV2 = &pMesh->mVertices[face.mIndices[1]];
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const aiVector3D* pV3 = &pMesh->mVertices[face.mIndices[face.mNumIndices-1]];
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const aiVector3D vNor = ((*pV2 - *pV1) ^ (*pV3 - *pV1)).NormalizeSafe();
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for (unsigned int i = 0;i < face.mNumIndices;++i) {
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pMesh->mNormals[face.mIndices[i]] = vNor;
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}
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}
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// Set up a SpatialSort to quickly find all vertices close to a given position
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// check whether we can reuse the SpatialSort of a previous step.
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SpatialSort* vertexFinder = NULL;
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SpatialSort _vertexFinder;
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ai_real posEpsilon = ai_real( 1e-5 );
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if (shared) {
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std::vector<std::pair<SpatialSort,ai_real> >* avf;
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shared->GetProperty(AI_SPP_SPATIAL_SORT,avf);
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if (avf)
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{
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std::pair<SpatialSort,ai_real>& blubb = avf->operator [] (meshIndex);
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vertexFinder = &blubb.first;
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posEpsilon = blubb.second;
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}
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}
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if (!vertexFinder) {
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_vertexFinder.Fill(pMesh->mVertices, pMesh->mNumVertices, sizeof( aiVector3D));
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vertexFinder = &_vertexFinder;
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posEpsilon = ComputePositionEpsilon(pMesh);
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}
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std::vector<unsigned int> verticesFound;
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aiVector3D* pcNew = new aiVector3D[pMesh->mNumVertices];
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if (configMaxAngle >= AI_DEG_TO_RAD( 175.f )) {
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// There is no angle limit. Thus all vertices with positions close
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// to each other will receive the same vertex normal. This allows us
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// to optimize the whole algorithm a little bit ...
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std::vector<bool> abHad(pMesh->mNumVertices,false);
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for (unsigned int i = 0; i < pMesh->mNumVertices;++i) {
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if (abHad[i]) {
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continue;
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}
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// Get all vertices that share this one ...
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vertexFinder->FindPositions( pMesh->mVertices[i], posEpsilon, verticesFound);
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aiVector3D pcNor;
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for (unsigned int a = 0; a < verticesFound.size(); ++a) {
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const aiVector3D& v = pMesh->mNormals[verticesFound[a]];
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if (is_not_qnan(v.x))pcNor += v;
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}
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pcNor.NormalizeSafe();
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// Write the smoothed normal back to all affected normals
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for (unsigned int a = 0; a < verticesFound.size(); ++a)
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{
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unsigned int vidx = verticesFound[a];
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pcNew[vidx] = pcNor;
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abHad[vidx] = true;
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}
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}
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}
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// Slower code path if a smooth angle is set. There are many ways to achieve
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// the effect, this one is the most straightforward one.
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else {
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const ai_real fLimit = std::cos(configMaxAngle);
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for (unsigned int i = 0; i < pMesh->mNumVertices;++i) {
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// Get all vertices that share this one ...
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vertexFinder->FindPositions( pMesh->mVertices[i] , posEpsilon, verticesFound);
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aiVector3D vr = pMesh->mNormals[i];
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aiVector3D pcNor;
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for (unsigned int a = 0; a < verticesFound.size(); ++a) {
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aiVector3D v = pMesh->mNormals[verticesFound[a]];
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// Check whether the angle between the two normals is not too large.
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// Skip the angle check on our own normal to avoid false negatives
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// (v*v is not guaranteed to be 1.0 for all unit vectors v)
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if (is_not_qnan(v.x) && (verticesFound[a] == i || (v * vr >= fLimit)))
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pcNor += v;
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}
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pcNew[i] = pcNor.NormalizeSafe();
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}
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}
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delete[] pMesh->mNormals;
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pMesh->mNormals = pcNew;
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return true;
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}
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