add assimp submodule

1 files changed, 688 insertions, 0 deletions

diff --git a/src/mesh/assimp-master/code/PostProcessing/PretransformVertices.cpp b/src/mesh/assimp-master/code/PostProcessing/PretransformVertices.cpp
new file mode 100644
index 0000000..ec7b878
--- /dev/null
+++ b/src/mesh/assimp-master/code/PostProcessing/PretransformVertices.cpp
@@ -0,0 +1,688 @@
+/*
+---------------------------------------------------------------------------
+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 PretransformVertices.cpp
+ *  @brief Implementation of the "PretransformVertices" post processing step
+*/
+
+#include "PretransformVertices.h"
+#include "ConvertToLHProcess.h"
+#include "ProcessHelper.h"
+#include <assimp/Exceptional.h>
+#include <assimp/SceneCombiner.h>
+
+using namespace Assimp;
+
+// some array offsets
+#define AI_PTVS_VERTEX 0x0
+#define AI_PTVS_FACE 0x1
+
+// ------------------------------------------------------------------------------------------------
+// Constructor to be privately used by Importer
+PretransformVertices::PretransformVertices() :
+		configKeepHierarchy(false),
+		configNormalize(false),
+		configTransform(false),
+		configTransformation(),
+		mConfigPointCloud(false) {
+	// empty
+}
+
+// ------------------------------------------------------------------------------------------------
+// Destructor, private as well
+PretransformVertices::~PretransformVertices() {
+	// nothing to do here
+}
+
+// ------------------------------------------------------------------------------------------------
+// Returns whether the processing step is present in the given flag field.
+bool PretransformVertices::IsActive(unsigned int pFlags) const {
+	return (pFlags & aiProcess_PreTransformVertices) != 0;
+}
+
+// ------------------------------------------------------------------------------------------------
+// Setup import configuration
+void PretransformVertices::SetupProperties(const Importer *pImp) {
+	// Get the current value of AI_CONFIG_PP_PTV_KEEP_HIERARCHY, AI_CONFIG_PP_PTV_NORMALIZE,
+	// AI_CONFIG_PP_PTV_ADD_ROOT_TRANSFORMATION and AI_CONFIG_PP_PTV_ROOT_TRANSFORMATION
+	configKeepHierarchy = (0 != pImp->GetPropertyInteger(AI_CONFIG_PP_PTV_KEEP_HIERARCHY, 0));
+	configNormalize = (0 != pImp->GetPropertyInteger(AI_CONFIG_PP_PTV_NORMALIZE, 0));
+	configTransform = (0 != pImp->GetPropertyInteger(AI_CONFIG_PP_PTV_ADD_ROOT_TRANSFORMATION, 0));
+
+	configTransformation = pImp->GetPropertyMatrix(AI_CONFIG_PP_PTV_ROOT_TRANSFORMATION, aiMatrix4x4());
+
+	mConfigPointCloud = pImp->GetPropertyBool(AI_CONFIG_EXPORT_POINT_CLOUDS);
+}
+
+// ------------------------------------------------------------------------------------------------
+// Count the number of nodes
+unsigned int PretransformVertices::CountNodes(const aiNode *pcNode) const {
+	unsigned int iRet = 1;
+	for (unsigned int i = 0; i < pcNode->mNumChildren; ++i) {
+		iRet += CountNodes(pcNode->mChildren[i]);
+	}
+	return iRet;
+}
+
+// ------------------------------------------------------------------------------------------------
+// Get a bitwise combination identifying the vertex format of a mesh
+unsigned int PretransformVertices::GetMeshVFormat(aiMesh *pcMesh) const {
+	// the vertex format is stored in aiMesh::mBones for later retrieval.
+	// there isn't a good reason to compute it a few hundred times
+	// from scratch. The pointer is unused as animations are lost
+	// during PretransformVertices.
+	if (pcMesh->mBones)
+		return (unsigned int)(uint64_t)pcMesh->mBones;
+
+	const unsigned int iRet = GetMeshVFormatUnique(pcMesh);
+
+	// store the value for later use
+	pcMesh->mBones = (aiBone **)(uint64_t)iRet;
+	return iRet;
+}
+
+// ------------------------------------------------------------------------------------------------
+// Count the number of vertices in the whole scene and a given
+// material index
+void PretransformVertices::CountVerticesAndFaces(const aiScene *pcScene, const aiNode *pcNode, unsigned int iMat,
+		unsigned int iVFormat, unsigned int *piFaces, unsigned int *piVertices) const {
+	for (unsigned int i = 0; i < pcNode->mNumMeshes; ++i) {
+		aiMesh *pcMesh = pcScene->mMeshes[pcNode->mMeshes[i]];
+		if (iMat == pcMesh->mMaterialIndex && iVFormat == GetMeshVFormat(pcMesh)) {
+			*piVertices += pcMesh->mNumVertices;
+			*piFaces += pcMesh->mNumFaces;
+		}
+	}
+	for (unsigned int i = 0; i < pcNode->mNumChildren; ++i) {
+		CountVerticesAndFaces(pcScene, pcNode->mChildren[i], iMat,
+				iVFormat, piFaces, piVertices);
+	}
+}
+
+// ------------------------------------------------------------------------------------------------
+// Collect vertex/face data
+void PretransformVertices::CollectData(const aiScene *pcScene, const aiNode *pcNode, unsigned int iMat,
+		unsigned int iVFormat, aiMesh *pcMeshOut,
+		unsigned int aiCurrent[2], unsigned int *num_refs) const {
+	// No need to multiply if there's no transformation
+	const bool identity = pcNode->mTransformation.IsIdentity();
+	for (unsigned int i = 0; i < pcNode->mNumMeshes; ++i) {
+		aiMesh *pcMesh = pcScene->mMeshes[pcNode->mMeshes[i]];
+		if (iMat == pcMesh->mMaterialIndex && iVFormat == GetMeshVFormat(pcMesh)) {
+			// Decrement mesh reference counter
+			unsigned int &num_ref = num_refs[pcNode->mMeshes[i]];
+			ai_assert(0 != num_ref);
+			--num_ref;
+			// Save the name of the last mesh
+			if (num_ref == 0) {
+				pcMeshOut->mName = pcMesh->mName;
+			}
+
+			if (identity) {
+				// copy positions without modifying them
+				::memcpy(pcMeshOut->mVertices + aiCurrent[AI_PTVS_VERTEX],
+						pcMesh->mVertices,
+						pcMesh->mNumVertices * sizeof(aiVector3D));
+
+				if (iVFormat & 0x2) {
+					// copy normals without modifying them
+					::memcpy(pcMeshOut->mNormals + aiCurrent[AI_PTVS_VERTEX],
+							pcMesh->mNormals,
+							pcMesh->mNumVertices * sizeof(aiVector3D));
+				}
+				if (iVFormat & 0x4) {
+					// copy tangents without modifying them
+					::memcpy(pcMeshOut->mTangents + aiCurrent[AI_PTVS_VERTEX],
+							pcMesh->mTangents,
+							pcMesh->mNumVertices * sizeof(aiVector3D));
+					// copy bitangents without modifying them
+					::memcpy(pcMeshOut->mBitangents + aiCurrent[AI_PTVS_VERTEX],
+							pcMesh->mBitangents,
+							pcMesh->mNumVertices * sizeof(aiVector3D));
+				}
+			} else {
+				// copy positions, transform them to worldspace
+				for (unsigned int n = 0; n < pcMesh->mNumVertices; ++n) {
+					pcMeshOut->mVertices[aiCurrent[AI_PTVS_VERTEX] + n] = pcNode->mTransformation * pcMesh->mVertices[n];
+				}
+				aiMatrix4x4 mWorldIT = pcNode->mTransformation;
+				mWorldIT.Inverse().Transpose();
+
+				// TODO: implement Inverse() for aiMatrix3x3
+				aiMatrix3x3 m = aiMatrix3x3(mWorldIT);
+
+				if (iVFormat & 0x2) {
+					// copy normals, transform them to worldspace
+					for (unsigned int n = 0; n < pcMesh->mNumVertices; ++n) {
+						pcMeshOut->mNormals[aiCurrent[AI_PTVS_VERTEX] + n] =
+								(m * pcMesh->mNormals[n]).Normalize();
+					}
+				}
+				if (iVFormat & 0x4) {
+					// copy tangents and bitangents, transform them to worldspace
+					for (unsigned int n = 0; n < pcMesh->mNumVertices; ++n) {
+						pcMeshOut->mTangents[aiCurrent[AI_PTVS_VERTEX] + n] = (m * pcMesh->mTangents[n]).Normalize();
+						pcMeshOut->mBitangents[aiCurrent[AI_PTVS_VERTEX] + n] = (m * pcMesh->mBitangents[n]).Normalize();
+					}
+				}
+			}
+			unsigned int p = 0;
+			while (iVFormat & (0x100 << p)) {
+				// copy texture coordinates
+				memcpy(pcMeshOut->mTextureCoords[p] + aiCurrent[AI_PTVS_VERTEX],
+						pcMesh->mTextureCoords[p],
+						pcMesh->mNumVertices * sizeof(aiVector3D));
+				++p;
+			}
+			p = 0;
+			while (iVFormat & (0x1000000 << p)) {
+				// copy vertex colors
+				memcpy(pcMeshOut->mColors[p] + aiCurrent[AI_PTVS_VERTEX],
+						pcMesh->mColors[p],
+						pcMesh->mNumVertices * sizeof(aiColor4D));
+				++p;
+			}
+			// now we need to copy all faces. since we will delete the source mesh afterwards,
+			// we don't need to reallocate the array of indices except if this mesh is
+			// referenced multiple times.
+			for (unsigned int planck = 0; planck < pcMesh->mNumFaces; ++planck) {
+				aiFace &f_src = pcMesh->mFaces[planck];
+				aiFace &f_dst = pcMeshOut->mFaces[aiCurrent[AI_PTVS_FACE] + planck];
+
+				const unsigned int num_idx = f_src.mNumIndices;
+
+				f_dst.mNumIndices = num_idx;
+
+				unsigned int *pi;
+				if (!num_ref) { /* if last time the mesh is referenced -> no reallocation */
+					pi = f_dst.mIndices = f_src.mIndices;
+
+					// offset all vertex indices
+					for (unsigned int hahn = 0; hahn < num_idx; ++hahn) {
+						pi[hahn] += aiCurrent[AI_PTVS_VERTEX];
+					}
+				} else {
+					pi = f_dst.mIndices = new unsigned int[num_idx];
+
+					// copy and offset all vertex indices
+					for (unsigned int hahn = 0; hahn < num_idx; ++hahn) {
+						pi[hahn] = f_src.mIndices[hahn] + aiCurrent[AI_PTVS_VERTEX];
+					}
+				}
+
+				// Update the mPrimitiveTypes member of the mesh
+				switch (pcMesh->mFaces[planck].mNumIndices) {
+					case 0x1:
+						pcMeshOut->mPrimitiveTypes |= aiPrimitiveType_POINT;
+						break;
+					case 0x2:
+						pcMeshOut->mPrimitiveTypes |= aiPrimitiveType_LINE;
+						break;
+					case 0x3:
+						pcMeshOut->mPrimitiveTypes |= aiPrimitiveType_TRIANGLE;
+						break;
+					default:
+						pcMeshOut->mPrimitiveTypes |= aiPrimitiveType_POLYGON;
+						break;
+				};
+			}
+			aiCurrent[AI_PTVS_VERTEX] += pcMesh->mNumVertices;
+			aiCurrent[AI_PTVS_FACE] += pcMesh->mNumFaces;
+		}
+	}
+
+	// append all children of us
+	for (unsigned int i = 0; i < pcNode->mNumChildren; ++i) {
+		CollectData(pcScene, pcNode->mChildren[i], iMat,
+				iVFormat, pcMeshOut, aiCurrent, num_refs);
+	}
+}
+
+// ------------------------------------------------------------------------------------------------
+// Get a list of all vertex formats that occur for a given material index
+// The output list contains duplicate elements
+void PretransformVertices::GetVFormatList(const aiScene *pcScene, unsigned int iMat,
+		std::list<unsigned int> &aiOut) const {
+	for (unsigned int i = 0; i < pcScene->mNumMeshes; ++i) {
+		aiMesh *pcMesh = pcScene->mMeshes[i];
+		if (iMat == pcMesh->mMaterialIndex) {
+			aiOut.push_back(GetMeshVFormat(pcMesh));
+		}
+	}
+}
+
+// ------------------------------------------------------------------------------------------------
+// Compute the absolute transformation matrices of each node
+void PretransformVertices::ComputeAbsoluteTransform(aiNode *pcNode) {
+	if (pcNode->mParent) {
+		pcNode->mTransformation = pcNode->mParent->mTransformation * pcNode->mTransformation;
+	}
+
+	for (unsigned int i = 0; i < pcNode->mNumChildren; ++i) {
+		ComputeAbsoluteTransform(pcNode->mChildren[i]);
+	}
+}
+
+// ------------------------------------------------------------------------------------------------
+// Apply the node transformation to a mesh
+void PretransformVertices::ApplyTransform(aiMesh *mesh, const aiMatrix4x4 &mat) const {
+	// Check whether we need to transform the coordinates at all
+	if (!mat.IsIdentity()) {
+
+		// Check for odd negative scale (mirror)
+		if (mesh->HasFaces() && mat.Determinant() < 0) {
+			// Reverse the mesh face winding order
+			FlipWindingOrderProcess::ProcessMesh(mesh);
+		}
+
+		// Update positions
+		if (mesh->HasPositions()) {
+			for (unsigned int i = 0; i < mesh->mNumVertices; ++i) {
+				mesh->mVertices[i] = mat * mesh->mVertices[i];
+			}
+		}
+
+		// Update normals and tangents
+		if (mesh->HasNormals() || mesh->HasTangentsAndBitangents()) {
+			const aiMatrix3x3 m = aiMatrix3x3(mat).Inverse().Transpose();
+
+			if (mesh->HasNormals()) {
+				for (unsigned int i = 0; i < mesh->mNumVertices; ++i) {
+					mesh->mNormals[i] = (m * mesh->mNormals[i]).Normalize();
+				}
+			}
+			if (mesh->HasTangentsAndBitangents()) {
+				for (unsigned int i = 0; i < mesh->mNumVertices; ++i) {
+					mesh->mTangents[i] = (m * mesh->mTangents[i]).Normalize();
+					mesh->mBitangents[i] = (m * mesh->mBitangents[i]).Normalize();
+				}
+			}
+		}
+	}
+}
+
+// ------------------------------------------------------------------------------------------------
+// Simple routine to build meshes in worldspace, no further optimization
+void PretransformVertices::BuildWCSMeshes(std::vector<aiMesh *> &out, aiMesh **in,
+		unsigned int numIn, aiNode *node) const {
+	// NOTE:
+	//  aiMesh::mNumBones store original source mesh, or UINT_MAX if not a copy
+	//  aiMesh::mBones store reference to abs. transform we multiplied with
+
+	// process meshes
+	for (unsigned int i = 0; i < node->mNumMeshes; ++i) {
+		aiMesh *mesh = in[node->mMeshes[i]];
+
+		// check whether we can operate on this mesh
+		if (!mesh->mBones || *reinterpret_cast<aiMatrix4x4 *>(mesh->mBones) == node->mTransformation) {
+			// yes, we can.
+			mesh->mBones = reinterpret_cast<aiBone **>(&node->mTransformation);
+			mesh->mNumBones = UINT_MAX;
+		} else {
+
+			// try to find us in the list of newly created meshes
+			for (unsigned int n = 0; n < out.size(); ++n) {
+				aiMesh *ctz = out[n];
+				if (ctz->mNumBones == node->mMeshes[i] && *reinterpret_cast<aiMatrix4x4 *>(ctz->mBones) == node->mTransformation) {
+
+					// ok, use this one. Update node mesh index
+					node->mMeshes[i] = numIn + n;
+				}
+			}
+			if (node->mMeshes[i] < numIn) {
+				// Worst case. Need to operate on a full copy of the mesh
+				ASSIMP_LOG_INFO("PretransformVertices: Copying mesh due to mismatching transforms");
+				aiMesh *ntz;
+
+				const unsigned int tmp = mesh->mNumBones; //
+				mesh->mNumBones = 0;
+				SceneCombiner::Copy(&ntz, mesh);
+				mesh->mNumBones = tmp;
+
+				ntz->mNumBones = node->mMeshes[i];
+				ntz->mBones = reinterpret_cast<aiBone **>(&node->mTransformation);
+
+				out.push_back(ntz);
+
+				node->mMeshes[i] = static_cast<unsigned int>(numIn + out.size() - 1);
+			}
+		}
+	}
+
+	// call children
+	for (unsigned int i = 0; i < node->mNumChildren; ++i)
+		BuildWCSMeshes(out, in, numIn, node->mChildren[i]);
+}
+
+// ------------------------------------------------------------------------------------------------
+// Reset transformation matrices to identity
+void PretransformVertices::MakeIdentityTransform(aiNode *nd) const {
+	nd->mTransformation = aiMatrix4x4();
+
+	// call children
+	for (unsigned int i = 0; i < nd->mNumChildren; ++i)
+		MakeIdentityTransform(nd->mChildren[i]);
+}
+
+// ------------------------------------------------------------------------------------------------
+// Build reference counters for all meshes
+void PretransformVertices::BuildMeshRefCountArray(const aiNode *nd, unsigned int *refs) const {
+	for (unsigned int i = 0; i < nd->mNumMeshes; ++i)
+		refs[nd->mMeshes[i]]++;
+
+	// call children
+	for (unsigned int i = 0; i < nd->mNumChildren; ++i)
+		BuildMeshRefCountArray(nd->mChildren[i], refs);
+}
+
+// ------------------------------------------------------------------------------------------------
+// Executes the post processing step on the given imported data.
+void PretransformVertices::Execute(aiScene *pScene) {
+	ASSIMP_LOG_DEBUG("PretransformVerticesProcess begin");
+
+	// Return immediately if we have no meshes
+	if (!pScene->mNumMeshes)
+		return;
+
+	const unsigned int iOldMeshes = pScene->mNumMeshes;
+	const unsigned int iOldAnimationChannels = pScene->mNumAnimations;
+	const unsigned int iOldNodes = CountNodes(pScene->mRootNode);
+
+	if (configTransform) {
+		pScene->mRootNode->mTransformation = configTransformation * pScene->mRootNode->mTransformation;
+	}
+
+	// first compute absolute transformation matrices for all nodes
+	ComputeAbsoluteTransform(pScene->mRootNode);
+
+	// Delete aiMesh::mBones for all meshes. The bones are
+	// removed during this step and we need the pointer as
+	// temporary storage
+	for (unsigned int i = 0; i < pScene->mNumMeshes; ++i) {
+		aiMesh *mesh = pScene->mMeshes[i];
+
+		for (unsigned int a = 0; a < mesh->mNumBones; ++a)
+			delete mesh->mBones[a];
+
+		delete[] mesh->mBones;
+        mesh->mBones = nullptr;
+	}
+
+	// now build a list of output meshes
+	std::vector<aiMesh *> apcOutMeshes;
+
+	// Keep scene hierarchy? It's an easy job in this case ...
+	// we go on and transform all meshes, if one is referenced by nodes
+	// with different absolute transformations a depth copy of the mesh
+	// is required.
+	if (configKeepHierarchy) {
+
+		// Hack: store the matrix we're transforming a mesh with in aiMesh::mBones
+		BuildWCSMeshes(apcOutMeshes, pScene->mMeshes, pScene->mNumMeshes, pScene->mRootNode);
+
+		// ... if new meshes have been generated, append them to the end of the scene
+		if (apcOutMeshes.size() > 0) {
+			aiMesh **npp = new aiMesh *[pScene->mNumMeshes + apcOutMeshes.size()];
+
+			memcpy(npp, pScene->mMeshes, sizeof(aiMesh *) * pScene->mNumMeshes);
+			memcpy(npp + pScene->mNumMeshes, &apcOutMeshes[0], sizeof(aiMesh *) * apcOutMeshes.size());
+
+			pScene->mNumMeshes += static_cast<unsigned int>(apcOutMeshes.size());
+			delete[] pScene->mMeshes;
+			pScene->mMeshes = npp;
+		}
+
+		// now iterate through all meshes and transform them to world-space
+		for (unsigned int i = 0; i < pScene->mNumMeshes; ++i) {
+			ApplyTransform(pScene->mMeshes[i], *reinterpret_cast<aiMatrix4x4 *>(pScene->mMeshes[i]->mBones));
+
+			// prevent improper destruction
+            pScene->mMeshes[i]->mBones = nullptr;
+			pScene->mMeshes[i]->mNumBones = 0;
+		}
+	} else {
+		apcOutMeshes.reserve(static_cast<size_t>(pScene->mNumMaterials) << 1u);
+		std::list<unsigned int> aiVFormats;
+
+		std::vector<unsigned int> s(pScene->mNumMeshes, 0);
+		BuildMeshRefCountArray(pScene->mRootNode, &s[0]);
+
+		for (unsigned int i = 0; i < pScene->mNumMaterials; ++i) {
+			// get the list of all vertex formats for this material
+			aiVFormats.clear();
+			GetVFormatList(pScene, i, aiVFormats);
+			aiVFormats.sort();
+			aiVFormats.unique();
+			for (std::list<unsigned int>::const_iterator j = aiVFormats.begin(); j != aiVFormats.end(); ++j) {
+				unsigned int iVertices = 0;
+				unsigned int iFaces = 0;
+				CountVerticesAndFaces(pScene, pScene->mRootNode, i, *j, &iFaces, &iVertices);
+				if (0 != iFaces && 0 != iVertices) {
+					apcOutMeshes.push_back(new aiMesh());
+					aiMesh *pcMesh = apcOutMeshes.back();
+					pcMesh->mNumFaces = iFaces;
+					pcMesh->mNumVertices = iVertices;
+					pcMesh->mFaces = new aiFace[iFaces];
+					pcMesh->mVertices = new aiVector3D[iVertices];
+					pcMesh->mMaterialIndex = i;
+					if ((*j) & 0x2) pcMesh->mNormals = new aiVector3D[iVertices];
+					if ((*j) & 0x4) {
+						pcMesh->mTangents = new aiVector3D[iVertices];
+						pcMesh->mBitangents = new aiVector3D[iVertices];
+					}
+					iFaces = 0;
+					while ((*j) & (0x100 << iFaces)) {
+						pcMesh->mTextureCoords[iFaces] = new aiVector3D[iVertices];
+						if ((*j) & (0x10000 << iFaces))
+							pcMesh->mNumUVComponents[iFaces] = 3;
+						else
+							pcMesh->mNumUVComponents[iFaces] = 2;
+						iFaces++;
+					}
+					iFaces = 0;
+					while ((*j) & (0x1000000 << iFaces))
+						pcMesh->mColors[iFaces++] = new aiColor4D[iVertices];
+
+					// fill the mesh ...
+					unsigned int aiTemp[2] = { 0, 0 };
+					CollectData(pScene, pScene->mRootNode, i, *j, pcMesh, aiTemp, &s[0]);
+				}
+			}
+		}
+
+		// If no meshes are referenced in the node graph it is possible that we get no output meshes.
+		if (apcOutMeshes.empty()) {
+
+			throw DeadlyImportError("No output meshes: all meshes are orphaned and are not referenced by any nodes");
+		} else {
+			// now delete all meshes in the scene and build a new mesh list
+			for (unsigned int i = 0; i < pScene->mNumMeshes; ++i) {
+				aiMesh *mesh = pScene->mMeshes[i];
+				mesh->mNumBones = 0;
+                mesh->mBones = nullptr;
+
+				// we're reusing the face index arrays. avoid destruction
+				for (unsigned int a = 0; a < mesh->mNumFaces; ++a) {
+					mesh->mFaces[a].mNumIndices = 0;
+                    mesh->mFaces[a].mIndices = nullptr;
+				}
+
+				delete mesh;
+
+				// Invalidate the contents of the old mesh array. We will most
+				// likely have less output meshes now, so the last entries of
+				// the mesh array are not overridden. We set them to nullptr to
+				// make sure the developer gets notified when his application
+				// attempts to access these fields ...
+                mesh = nullptr;
+			}
+
+			// It is impossible that we have more output meshes than
+			// input meshes, so we can easily reuse the old mesh array
+			pScene->mNumMeshes = (unsigned int)apcOutMeshes.size();
+			for (unsigned int i = 0; i < pScene->mNumMeshes; ++i) {
+				pScene->mMeshes[i] = apcOutMeshes[i];
+			}
+		}
+	}
+
+	// remove all animations from the scene
+	for (unsigned int i = 0; i < pScene->mNumAnimations; ++i)
+		delete pScene->mAnimations[i];
+	delete[] pScene->mAnimations;
+
+	pScene->mAnimations = nullptr;
+	pScene->mNumAnimations = 0;
+
+	// --- we need to keep all cameras and lights
+	for (unsigned int i = 0; i < pScene->mNumCameras; ++i) {
+		aiCamera *cam = pScene->mCameras[i];
+		const aiNode *nd = pScene->mRootNode->FindNode(cam->mName);
+        ai_assert(nullptr != nd);
+
+		// multiply all properties of the camera with the absolute
+		// transformation of the corresponding node
+		cam->mPosition = nd->mTransformation * cam->mPosition;
+		cam->mLookAt = aiMatrix3x3(nd->mTransformation) * cam->mLookAt;
+		cam->mUp = aiMatrix3x3(nd->mTransformation) * cam->mUp;
+	}
+
+	for (unsigned int i = 0; i < pScene->mNumLights; ++i) {
+		aiLight *l = pScene->mLights[i];
+		const aiNode *nd = pScene->mRootNode->FindNode(l->mName);
+        ai_assert(nullptr != nd);
+
+		// multiply all properties of the camera with the absolute
+		// transformation of the corresponding node
+		l->mPosition = nd->mTransformation * l->mPosition;
+		l->mDirection = aiMatrix3x3(nd->mTransformation) * l->mDirection;
+		l->mUp = aiMatrix3x3(nd->mTransformation) * l->mUp;
+	}
+
+	if (!configKeepHierarchy) {
+
+		// now delete all nodes in the scene and build a new
+		// flat node graph with a root node and some level 1 children
+		aiNode *newRoot = new aiNode();
+		newRoot->mName = pScene->mRootNode->mName;
+		delete pScene->mRootNode;
+		pScene->mRootNode = newRoot;
+
+		if (1 == pScene->mNumMeshes && !pScene->mNumLights && !pScene->mNumCameras) {
+			pScene->mRootNode->mNumMeshes = 1;
+			pScene->mRootNode->mMeshes = new unsigned int[1];
+			pScene->mRootNode->mMeshes[0] = 0;
+		} else {
+			pScene->mRootNode->mNumChildren = pScene->mNumMeshes + pScene->mNumLights + pScene->mNumCameras;
+			aiNode **nodes = pScene->mRootNode->mChildren = new aiNode *[pScene->mRootNode->mNumChildren];
+
+			// generate mesh nodes
+			for (unsigned int i = 0; i < pScene->mNumMeshes; ++i, ++nodes) {
+				aiNode *pcNode = new aiNode();
+				*nodes = pcNode;
+				pcNode->mParent = pScene->mRootNode;
+				pcNode->mName = pScene->mMeshes[i]->mName;
+
+				// setup mesh indices
+				pcNode->mNumMeshes = 1;
+				pcNode->mMeshes = new unsigned int[1];
+				pcNode->mMeshes[0] = i;
+			}
+			// generate light nodes
+			for (unsigned int i = 0; i < pScene->mNumLights; ++i, ++nodes) {
+				aiNode *pcNode = new aiNode();
+				*nodes = pcNode;
+				pcNode->mParent = pScene->mRootNode;
+				pcNode->mName.length = ai_snprintf(pcNode->mName.data, MAXLEN, "light_%u", i);
+				pScene->mLights[i]->mName = pcNode->mName;
+			}
+			// generate camera nodes
+			for (unsigned int i = 0; i < pScene->mNumCameras; ++i, ++nodes) {
+				aiNode *pcNode = new aiNode();
+				*nodes = pcNode;
+				pcNode->mParent = pScene->mRootNode;
+				pcNode->mName.length = ::ai_snprintf(pcNode->mName.data, MAXLEN, "cam_%u", i);
+				pScene->mCameras[i]->mName = pcNode->mName;
+			}
+		}
+	} else {
+		// ... and finally set the transformation matrix of all nodes to identity
+		MakeIdentityTransform(pScene->mRootNode);
+	}
+
+	if (configNormalize) {
+		// compute the boundary of all meshes
+		aiVector3D min, max;
+		MinMaxChooser<aiVector3D>()(min, max);
+
+		for (unsigned int a = 0; a < pScene->mNumMeshes; ++a) {
+			aiMesh *m = pScene->mMeshes[a];
+			for (unsigned int i = 0; i < m->mNumVertices; ++i) {
+				min = std::min(m->mVertices[i], min);
+				max = std::max(m->mVertices[i], max);
+			}
+		}
+
+		// find the dominant axis
+		aiVector3D d = max - min;
+		const ai_real div = std::max(d.x, std::max(d.y, d.z)) * ai_real(0.5);
+
+		d = min + d * (ai_real)0.5;
+		for (unsigned int a = 0; a < pScene->mNumMeshes; ++a) {
+			aiMesh *m = pScene->mMeshes[a];
+			for (unsigned int i = 0; i < m->mNumVertices; ++i) {
+				m->mVertices[i] = (m->mVertices[i] - d) / div;
+			}
+		}
+	}
+
+	// print statistics
+	if (!DefaultLogger::isNullLogger()) {
+		ASSIMP_LOG_DEBUG("PretransformVerticesProcess finished");
+
+		ASSIMP_LOG_INFO("Removed ", iOldNodes, " nodes and ", iOldAnimationChannels, " animation channels (",
+				CountNodes(pScene->mRootNode), " output nodes)");
+		ASSIMP_LOG_INFO("Kept ", pScene->mNumLights, " lights and ", pScene->mNumCameras, " cameras.");
+		ASSIMP_LOG_INFO("Moved ", iOldMeshes, " meshes to WCS (number of output meshes: ", pScene->mNumMeshes, ")");
+	}
+}