/* --------------------------------------------------------------------------- Open Asset Import Library (assimp) --------------------------------------------------------------------------- Copyright (c) 2006-2024, 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 RemoveRedundantMaterials.cpp * @brief Implementation of the "RemoveRedundantMaterials" post processing step */ // internal headers #include "RemoveRedundantMaterials.h" #include #include "ProcessHelper.h" #include "Material/MaterialSystem.h" #include #include using namespace Assimp; // ------------------------------------------------------------------------------------------------ // Constructor to be privately used by Importer RemoveRedundantMatsProcess::RemoveRedundantMatsProcess() : mConfigFixedMaterials() {} // ------------------------------------------------------------------------------------------------ // Returns whether the processing step is present in the given flag field. bool RemoveRedundantMatsProcess::IsActive( unsigned int pFlags) const { return (pFlags & aiProcess_RemoveRedundantMaterials) != 0; } // ------------------------------------------------------------------------------------------------ // Setup import properties void RemoveRedundantMatsProcess::SetupProperties(const Importer* pImp) { // Get value of AI_CONFIG_PP_RRM_EXCLUDE_LIST mConfigFixedMaterials = pImp->GetPropertyString(AI_CONFIG_PP_RRM_EXCLUDE_LIST,""); } // ------------------------------------------------------------------------------------------------ // Executes the post processing step on the given imported data. void RemoveRedundantMatsProcess::Execute( aiScene* pScene) { ASSIMP_LOG_DEBUG("RemoveRedundantMatsProcess begin"); unsigned int redundantRemoved = 0, unreferencedRemoved = 0; if (pScene->mNumMaterials == 0) { return; } // Find out which materials are referenced by meshes std::vector abReferenced(pScene->mNumMaterials,false); for (unsigned int i = 0;i < pScene->mNumMeshes;++i) abReferenced[pScene->mMeshes[i]->mMaterialIndex] = true; // If a list of materials to be excluded was given, match the list with // our imported materials and 'salt' all positive matches to ensure that // we get unique hashes later. if (mConfigFixedMaterials.length()) { std::list strings; ConvertListToStrings(mConfigFixedMaterials,strings); for (unsigned int i = 0; i < pScene->mNumMaterials;++i) { aiMaterial* mat = pScene->mMaterials[i]; aiString name; mat->Get(AI_MATKEY_NAME,name); if (name.length) { std::list::const_iterator it = std::find(strings.begin(), strings.end(), name.data); if (it != strings.end()) { // Our brilliant 'salt': A single material property with ~ as first // character to mark it as internal and temporary. const int dummy = 1; ((aiMaterial*)mat)->AddProperty(&dummy,1,"~RRM.UniqueMaterial",0,0); // Keep this material even if no mesh references it abReferenced[i] = true; ASSIMP_LOG_VERBOSE_DEBUG( "Found positive match in exclusion list: \'", name.data, "\'"); } } } } // TODO: re-implement this algorithm to work in-place unsigned int *aiMappingTable = new unsigned int[pScene->mNumMaterials]; for ( unsigned int i=0; imNumMaterials; i++ ) { aiMappingTable[ i ] = 0; } unsigned int iNewNum = 0; // Iterate through all materials and calculate a hash for them // store all hashes in a list and so a quick search whether // we do already have a specific hash. This allows us to // determine which materials are identical. uint32_t *aiHashes = new uint32_t[ pScene->mNumMaterials ];; for (unsigned int i = 0; i < pScene->mNumMaterials;++i) { // No mesh is referencing this material, remove it. if (!abReferenced[i]) { ++unreferencedRemoved; delete pScene->mMaterials[i]; pScene->mMaterials[i] = nullptr; continue; } // Check all previously mapped materials for a matching hash. // On a match we can delete this material and just make it ref to the same index. uint32_t me = aiHashes[i] = ComputeMaterialHash(pScene->mMaterials[i]); for (unsigned int a = 0; a < i;++a) { if (abReferenced[a] && me == aiHashes[a]) { ++redundantRemoved; me = 0; aiMappingTable[i] = aiMappingTable[a]; delete pScene->mMaterials[i]; pScene->mMaterials[i] = nullptr; break; } } // This is a new material that is referenced, add to the map. if (me) { aiMappingTable[i] = iNewNum++; } } // If the new material count differs from the original, // we need to rebuild the material list and remap mesh material indexes. if (iNewNum < 1) { //throw DeadlyImportError("No materials remaining"); return; } if (iNewNum != pScene->mNumMaterials) { ai_assert(iNewNum > 0); aiMaterial** ppcMaterials = new aiMaterial*[iNewNum]; ::memset(ppcMaterials,0,sizeof(void*)*iNewNum); for (unsigned int p = 0; p < pScene->mNumMaterials;++p) { // if the material is not referenced ... remove it if (!abReferenced[p]) { continue; } // generate new names for modified materials that had no names const unsigned int idx = aiMappingTable[p]; if (ppcMaterials[idx]) { aiString sz; if( ppcMaterials[idx]->Get(AI_MATKEY_NAME, sz) != AI_SUCCESS ) { sz.length = ::ai_snprintf(sz.data,MAXLEN,"JoinedMaterial_#%u",p); ((aiMaterial*)ppcMaterials[idx])->AddProperty(&sz,AI_MATKEY_NAME); } } else { ppcMaterials[idx] = pScene->mMaterials[p]; } } // update all material indices for (unsigned int p = 0; p < pScene->mNumMeshes;++p) { aiMesh* mesh = pScene->mMeshes[p]; ai_assert(nullptr != mesh); mesh->mMaterialIndex = aiMappingTable[mesh->mMaterialIndex]; } // delete the old material list delete[] pScene->mMaterials; pScene->mMaterials = ppcMaterials; pScene->mNumMaterials = iNewNum; } // delete temporary storage delete[] aiHashes; delete[] aiMappingTable; if (redundantRemoved == 0 && unreferencedRemoved == 0) { ASSIMP_LOG_DEBUG("RemoveRedundantMatsProcess finished "); } else { ASSIMP_LOG_INFO("RemoveRedundantMatsProcess finished. Removed ", redundantRemoved, " redundant and ", unreferencedRemoved, " unused materials."); } }