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Diffstat (limited to 'libs/assimp/code/PostProcessing/FixNormalsStep.cpp')
| -rw-r--r-- | libs/assimp/code/PostProcessing/FixNormalsStep.cpp | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/libs/assimp/code/PostProcessing/FixNormalsStep.cpp b/libs/assimp/code/PostProcessing/FixNormalsStep.cpp new file mode 100644 index 0000000..be01042 --- /dev/null +++ b/libs/assimp/code/PostProcessing/FixNormalsStep.cpp @@ -0,0 +1,184 @@ +/* +--------------------------------------------------------------------------- +Open Asset Import Library (assimp) +--------------------------------------------------------------------------- + +Copyright (c) 2006-2022, assimp team + + + +All rights reserved. + +Redistribution and use of this software in source and binary forms, +with or without modification, are permitted provided that the following +conditions are met: + +* Redistributions of source code must retain the above + copyright notice, this list of conditions and the + following disclaimer. + +* Redistributions in binary form must reproduce the above + copyright notice, this list of conditions and the + following disclaimer in the documentation and/or other + materials provided with the distribution. + +* 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 + written permission of the assimp team. + +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 +A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +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 +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +--------------------------------------------------------------------------- +*/ + +/** @file Implementation of the post processing step to invert + * all normals in meshes with infacing normals. + */ + +// internal headers +#include "FixNormalsStep.h" +#include <assimp/StringUtils.h> +#include <assimp/DefaultLogger.hpp> +#include <assimp/postprocess.h> +#include <assimp/scene.h> +#include <stdio.h> + + +using namespace Assimp; + + +// ------------------------------------------------------------------------------------------------ +// Constructor to be privately used by Importer +FixInfacingNormalsProcess::FixInfacingNormalsProcess() +{ + // nothing to do here +} + +// ------------------------------------------------------------------------------------------------ +// Destructor, private as well +FixInfacingNormalsProcess::~FixInfacingNormalsProcess() +{ + // nothing to do here +} + +// ------------------------------------------------------------------------------------------------ +// Returns whether the processing step is present in the given flag field. +bool FixInfacingNormalsProcess::IsActive( unsigned int pFlags) const +{ + return (pFlags & aiProcess_FixInfacingNormals) != 0; +} + +// ------------------------------------------------------------------------------------------------ +// Executes the post processing step on the given imported data. +void FixInfacingNormalsProcess::Execute( aiScene* pScene) +{ + ASSIMP_LOG_DEBUG("FixInfacingNormalsProcess begin"); + + bool bHas( false ); + for (unsigned int a = 0; a < pScene->mNumMeshes; ++a) { + if (ProcessMesh(pScene->mMeshes[a], a)) { + bHas = true; + } + } + + if (bHas) { + ASSIMP_LOG_DEBUG("FixInfacingNormalsProcess finished. Found issues."); + } else { + ASSIMP_LOG_DEBUG("FixInfacingNormalsProcess finished. No changes to the scene."); + } +} + +// ------------------------------------------------------------------------------------------------ +// Apply the step to the mesh +bool FixInfacingNormalsProcess::ProcessMesh( aiMesh* pcMesh, unsigned int index) +{ + ai_assert(nullptr != pcMesh); + + // Nothing to do if there are no model normals + if (!pcMesh->HasNormals()) { + return false; + } + + // Compute the bounding box of both the model vertices + normals and + // the unmodified model vertices. Then check whether the first BB + // is smaller than the second. In this case we can assume that the + // normals need to be flipped, although there are a few special cases .. + // convex, concave, planar models ... + + aiVector3D vMin0 (1e10f,1e10f,1e10f); + aiVector3D vMin1 (1e10f,1e10f,1e10f); + aiVector3D vMax0 (-1e10f,-1e10f,-1e10f); + aiVector3D vMax1 (-1e10f,-1e10f,-1e10f); + + for (unsigned int i = 0; i < pcMesh->mNumVertices;++i) + { + vMin1.x = std::min(vMin1.x,pcMesh->mVertices[i].x); + vMin1.y = std::min(vMin1.y,pcMesh->mVertices[i].y); + vMin1.z = std::min(vMin1.z,pcMesh->mVertices[i].z); + + vMax1.x = std::max(vMax1.x,pcMesh->mVertices[i].x); + vMax1.y = std::max(vMax1.y,pcMesh->mVertices[i].y); + vMax1.z = std::max(vMax1.z,pcMesh->mVertices[i].z); + + const aiVector3D vWithNormal = pcMesh->mVertices[i] + pcMesh->mNormals[i]; + + vMin0.x = std::min(vMin0.x,vWithNormal.x); + vMin0.y = std::min(vMin0.y,vWithNormal.y); + vMin0.z = std::min(vMin0.z,vWithNormal.z); + + vMax0.x = std::max(vMax0.x,vWithNormal.x); + vMax0.y = std::max(vMax0.y,vWithNormal.y); + vMax0.z = std::max(vMax0.z,vWithNormal.z); + } + + const float fDelta0_x = (vMax0.x - vMin0.x); + const float fDelta0_y = (vMax0.y - vMin0.y); + const float fDelta0_z = (vMax0.z - vMin0.z); + + const float fDelta1_x = (vMax1.x - vMin1.x); + const float fDelta1_y = (vMax1.y - vMin1.y); + const float fDelta1_z = (vMax1.z - vMin1.z); + + // Check whether the boxes are overlapping + if ((fDelta0_x > 0.0f) != (fDelta1_x > 0.0f))return false; + if ((fDelta0_y > 0.0f) != (fDelta1_y > 0.0f))return false; + if ((fDelta0_z > 0.0f) != (fDelta1_z > 0.0f))return false; + + // Check whether this is a planar surface + const float fDelta1_yz = fDelta1_y * fDelta1_z; + + if (fDelta1_x < 0.05f * std::sqrt( fDelta1_yz ))return false; + if (fDelta1_y < 0.05f * std::sqrt( fDelta1_z * fDelta1_x ))return false; + if (fDelta1_z < 0.05f * std::sqrt( fDelta1_y * fDelta1_x ))return false; + + // now compare the volumes of the bounding boxes + if (std::fabs(fDelta0_x * fDelta0_y * fDelta0_z) < std::fabs(fDelta1_x * fDelta1_yz)) { + if (!DefaultLogger::isNullLogger()) { + ASSIMP_LOG_INFO("Mesh ", index, ": Normals are facing inwards (or the mesh is planar)", index); + } + + // Invert normals + for (unsigned int i = 0; i < pcMesh->mNumVertices;++i) + pcMesh->mNormals[i] *= -1.0f; + + // ... and flip faces + for (unsigned int i = 0; i < pcMesh->mNumFaces;++i) + { + aiFace& face = pcMesh->mFaces[i]; + for( unsigned int b = 0; b < face.mNumIndices / 2; b++) + std::swap( face.mIndices[b], face.mIndices[ face.mNumIndices - 1 - b]); + } + return true; + } + return false; +} |