- manually merged C4D importer code from acgessler branch

- manually merged IFC bugfixes and improvements from schrompf branch

CMakeLists.txt

@@ -183,6 +183,52 @@ ENDIF ( ASSIMP_BUILD_COMPILER STREQUAL "")
 
 MARK_AS_ADVANCED ( ASSIMP_BUILD_ARCHITECTURE ASSIMP_BUILD_COMPILER )
 
+
+SET ( ASSIMP_BUILD_NONFREE_C4D_IMPORTER OFF CACHE BOOL
+	"Build the C4D importer, which relies on the non-free Melange SDK." 
+)
+
+IF (ASSIMP_BUILD_NONFREE_C4D_IMPORTER)
+	IF ( MSVC )
+		SET(C4D_INCLUDES "${CMAKE_CURRENT_SOURCE_DIR}/contrib/Melange/_melange/includes")
+		
+		# pick the correct prebuilt library
+		IF(MSVC11)
+			SET(C4D_LIB_POSTFIX "_2012md")
+		ELSEIF(MSVC10)
+			SET(C4D_LIB_POSTFIX "_2010md")
+		ELSEIF(MSVC90)
+			SET(C4D_LIB_POSTFIX "_2008md")
+		ELSE()
+			MESSAGE( FATAL_ERROR 
+				"C4D is currently only supported with MSVC 9, 10, 11"
+			)
+		ENDIF()
+		
+		IF(CMAKE_CL_64)
+			SET(C4D_LIB_ARCH_POSTFIX "_x64")
+		ELSE()
+			SET(C4D_LIB_ARCH_POSTFIX "")
+		ENDIF()
+		
+		SET(C4D_LIB_BASE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/contrib/Melange/_melange/lib/WIN")
+		
+		SET(C4D_DEBUG_LIBRARY "${C4D_LIB_BASE_PATH}/debug/_melange_lib${C4D_LIB_ARCH_POSTFIX}${C4D_LIB_POSTFIX}.lib")
+		SET(C4D_RELEASE_LIBRARY "${C4D_LIB_BASE_PATH}/release/_melange_lib${C4D_LIB_ARCH_POSTFIX}${C4D_LIB_POSTFIX}.lib")
+		
+		# winsock and winmm are necessary dependencies of melange (this is undocumented, but true.)
+		SET(C4D_EXTRA_LIBRARIES WSock32.lib Winmm.lib)
+	ELSE ()
+		MESSAGE( FATAL_ERROR 
+			"C4D is currently only available on Windows with melange SDK installed in contrib/Melange"
+		)
+	ENDIF ( MSVC )
+else (ASSIMP_BUILD_NONFREE_C4D_IMPORTER)
+	ADD_DEFINITIONS( -DASSIMP_BUILD_NO_C4D_IMPORTER )
+ENDIF (ASSIMP_BUILD_NONFREE_C4D_IMPORTER)
+
+
+
 ADD_SUBDIRECTORY( code/ )
 option ( ASSIMP_BUILD_ASSIMP_TOOLS
     "If the supplementary tools for Assimp are built in addition to the library."

code/C4DImporter.cpp

@@ -0,0 +1,641 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2012, 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  C4DImporter.cpp
+ *  @brief Implementation of the Cinema4D importer class.
+ */
+#include "AssimpPCH.h"
+
+// no #ifdefing here, Cinema4D support is carried out in a branch of assimp
+// where it is turned on in the CMake settings. 
+
+#ifndef _MSC_VER
+#	error C4D support is currently MSVC only
+#endif 
+
+#include "C4DImporter.h"
+#include "TinyFormatter.h"
+
+#if defined(_M_X64) || defined(__amd64__)
+#	define __C4D_64BIT
+#endif
+
+#define __PC 
+#include "c4d_file.h"
+#include "default_alien_overloads.h"
+
+using namespace _melange_;
+
+// overload this function and fill in your own unique data
+void GetWriterInfo(LONG &id, String &appname)
+{
+	id = 2424226; 
+	appname = "Open Asset Import Library";
+}
+
+using namespace Assimp;
+using namespace Assimp::Formatter;
+
+namespace Assimp {
+	template<> const std::string LogFunctions<C4DImporter>::log_prefix = "C4D: ";
+}
+
+static const aiImporterDesc desc = {
+	"Cinema4D Importer",
+	"",
+	"",
+	"",
+	aiImporterFlags_SupportBinaryFlavour,
+	0,
+	0,
+	0,
+	0,
+	"c4d"
+};
+
+
+// ------------------------------------------------------------------------------------------------
+C4DImporter::C4DImporter()
+{}
+
+// ------------------------------------------------------------------------------------------------
+C4DImporter::~C4DImporter()
+{}
+
+// ------------------------------------------------------------------------------------------------
+bool C4DImporter::CanRead( const std::string& pFile, IOSystem* pIOHandler, bool checkSig) const
+{
+	const std::string& extension = GetExtension(pFile);
+	if (extension == "c4d") {
+		return true;
+	}
+
+	else if ((!extension.length() || checkSig) && pIOHandler)	{
+		// TODO
+	}
+	return false;
+}
+
+// ------------------------------------------------------------------------------------------------
+const aiImporterDesc* C4DImporter::GetInfo () const
+{
+	return &desc;
+}
+
+// ------------------------------------------------------------------------------------------------
+void C4DImporter::SetupProperties(const Importer* /*pImp*/)
+{
+	// nothing to be done for the moment
+}
+
+
+// ------------------------------------------------------------------------------------------------
+// Imports the given file into the given scene structure. 
+void C4DImporter::InternReadFile( const std::string& pFile, 
+	aiScene* pScene, IOSystem* pIOHandler)
+{
+	boost::scoped_ptr<IOStream> file( pIOHandler->Open( pFile));
+
+	if( file.get() == NULL) {
+		ThrowException("failed to open file " + pFile);
+	}
+
+	const size_t file_size = file->FileSize();
+
+	std::vector<uint8_t> mBuffer(file_size);
+	file->Read(&mBuffer[0], 1, file_size);
+	
+	Filename f;
+	f.SetMemoryReadMode(&mBuffer[0], file_size);
+
+	// open document first
+	BaseDocument* doc = LoadDocument(f, SCENEFILTER_OBJECTS | SCENEFILTER_MATERIALS);
+	if(doc == NULL) {
+		ThrowException("failed to read document " + pFile);
+	}
+
+	pScene->mRootNode = new aiNode("<C4DRoot>");
+
+	// first convert all materials
+	ReadMaterials(doc->GetFirstMaterial());
+
+	// process C4D scenegraph recursively
+	try {
+		RecurseHierarchy(doc->GetFirstObject(), pScene->mRootNode);
+	}
+	catch(...) {
+		BOOST_FOREACH(aiMesh* mesh, meshes) {
+			delete mesh;
+		}
+		BaseDocument::Free(doc);
+		throw;
+	}
+	BaseDocument::Free(doc);
+
+	// copy meshes over
+	pScene->mNumMeshes = static_cast<unsigned int>(meshes.size());
+	pScene->mMeshes = new aiMesh*[pScene->mNumMeshes]();
+	std::copy(meshes.begin(), meshes.end(), pScene->mMeshes);
+
+	// copy materials over, adding a default material if necessary
+	unsigned int mat_count = static_cast<unsigned int>(materials.size());
+	BOOST_FOREACH(aiMesh* mesh, meshes) {
+		ai_assert(mesh->mMaterialIndex <= mat_count);
+		if(mesh->mMaterialIndex >= mat_count) {
+			++mat_count;
+
+			ScopeGuard<aiMaterial> def_material(new aiMaterial());
+			const aiString name(AI_DEFAULT_MATERIAL_NAME);
+			def_material->AddProperty(&name, AI_MATKEY_NAME);
+
+			materials.push_back(def_material.dismiss());
+			break;
+		}
+	}
+
+	pScene->mNumMaterials = static_cast<unsigned int>(materials.size());
+	pScene->mMaterials = new aiMaterial*[pScene->mNumMaterials]();
+	std::copy(materials.begin(), materials.end(), pScene->mMaterials);
+}
+
+
+// ------------------------------------------------------------------------------------------------
+bool C4DImporter::ReadShader(aiMaterial* out, _melange_::BaseShader* shader) 
+{
+	// based on Melange sample code (C4DImportExport.cpp)
+	while(shader) {
+		if(shader->GetType() == Xlayer) {
+			BaseContainer* container = shader->GetDataInstance();
+			GeData blend = container->GetData(SLA_LAYER_BLEND);
+			iBlendDataType* blend_list = reinterpret_cast<iBlendDataType*>(blend.GetCustomDataType(CUSTOMDATA_BLEND_LIST));
+			if (!blend_list)
+			{
+				LogWarn("ignoring XLayer shader: no blend list given");
+				continue;
+			}
+
+			LayerShaderLayer *lsl = dynamic_cast<LayerShaderLayer*>(blend_list->m_BlendLayers.GetObject(0));
+
+			// Ignore the actual layer blending - models for real-time rendering should not
+			// use them in a non-trivial way. Just try to find textures that we can apply
+			// to the model.
+			while (lsl)
+			{
+				if (lsl->GetType() == TypeFolder)
+				{
+					BlendFolder* const folder = dynamic_cast<BlendFolder*>(lsl); 
+					LayerShaderLayer *subLsl = dynamic_cast<LayerShaderLayer*>(folder->m_Children.GetObject(0));
+
+					while (subLsl)
+					{
+						if (subLsl->GetType() == TypeShader) {
+							BlendShader* const shader = dynamic_cast<BlendShader*>(subLsl); 
+							if(ReadShader(out, static_cast<BaseShader*>(shader->m_pLink->GetLink()))) {
+								return true;
+							}
+						}
+
+						subLsl = subLsl->GetNext();
+					}
+				}
+				else if (lsl->GetType() == TypeShader) {
+					BlendShader* const shader = dynamic_cast<BlendShader*>(lsl); 
+					if(ReadShader(out, static_cast<BaseShader*>(shader->m_pLink->GetLink()))) {
+						return true;
+					}
+				}
+
+				lsl = lsl->GetNext();	
+			}
+		}
+		else if ( shader->GetType() == Xbitmap )
+		{
+			aiString path;
+			shader->GetFileName().GetString().GetCString(path.data, MAXLEN-1);
+			path.length = ::strlen(path.data);
+			out->AddProperty(&path, AI_MATKEY_TEXTURE_DIFFUSE(0));
+			return true;
+		}
+		else {
+			LogWarn("ignoring shader type: " + std::string(GetObjectTypeName(shader->GetType())));
+		}
+		shader = shader->GetNext();
+	}
+	return false;
+}
+
+
+// ------------------------------------------------------------------------------------------------
+void C4DImporter::ReadMaterials(_melange_::BaseMaterial* mat)
+{
+	// based on Melange sample code
+	while (mat)
+	{
+		const String& name = mat->GetName();
+		if (mat->GetType() == Mmaterial)
+		{
+			aiMaterial* out = new aiMaterial();
+			material_mapping[mat] = static_cast<unsigned int>(materials.size());
+			materials.push_back(out);
+
+			aiString ai_name;
+			name.GetCString(ai_name.data, MAXLEN-1);
+			ai_name.length = ::strlen(ai_name.data);
+			out->AddProperty(&ai_name, AI_MATKEY_NAME);
+
+			Material& m = dynamic_cast<Material&>(*mat);
+
+			if (m.GetChannelState(CHANNEL_COLOR))
+			{
+				GeData data;
+				mat->GetParameter(MATERIAL_COLOR_COLOR, data);
+				Vector color = data.GetVector();
+				mat->GetParameter(MATERIAL_COLOR_BRIGHTNESS, data);
+				const Real brightness = data.GetReal();
+
+				color *= brightness;
+
+				aiVector3D v;
+				v.x = color.x;
+				v.y = color.y;
+				v.z = color.z;
+				out->AddProperty(&v, 1, AI_MATKEY_COLOR_DIFFUSE);
+			}
+
+			BaseShader* const shader = m.GetShader(MATERIAL_COLOR_SHADER);
+			if(shader) {
+				ReadShader(out, shader);
+			}
+		}
+		else
+		{
+			LogWarn("ignoring plugin material: " + std::string(GetObjectTypeName(mat->GetType())));
+		}
+		mat = mat->GetNext();
+	}
+}
+
+// ------------------------------------------------------------------------------------------------
+void C4DImporter::RecurseHierarchy(BaseObject* object, aiNode* parent)
+{
+	ai_assert(parent != NULL);
+	std::vector<aiNode*> nodes;
+
+	// based on Melange sample code
+	while (object)
+	{
+		const String& name = object->GetName();
+		const LONG type = object->GetType(); 
+		const Matrix& ml = object->GetMl(); 
+
+		aiString string;
+		name.GetCString(string.data, MAXLEN-1);
+		string.length = ::strlen(string.data);
+		aiNode* const nd = new aiNode();
+
+		nd->mParent = parent;
+		nd->mName = string;
+
+		nd->mTransformation.a1 = ml.v1.x;
+		nd->mTransformation.b1 = ml.v1.y;
+		nd->mTransformation.c1 = ml.v1.z;
+
+		nd->mTransformation.a2 = ml.v2.x;
+		nd->mTransformation.b2 = ml.v2.y;
+		nd->mTransformation.c2 = ml.v2.z;
+
+		nd->mTransformation.a3 = ml.v3.x;
+		nd->mTransformation.b3 = ml.v3.y;
+		nd->mTransformation.c3 = ml.v3.z;
+
+		nd->mTransformation.a4 = ml.off.x;
+		nd->mTransformation.b4 = ml.off.y;
+		nd->mTransformation.c4 = ml.off.z;
+
+		nodes.push_back(nd);
+		
+		GeData data; 
+		if (type == Ocamera)
+		{
+			object->GetParameter(CAMERAOBJECT_FOV, data);
+			// TODO: read camera
+		}
+		else if (type == Olight)
+		{
+			// TODO: read light
+		}
+		else if (type == Opolygon)
+		{
+			aiMesh* const mesh = ReadMesh(object);
+			if(mesh != NULL) {
+				nd->mNumMeshes = 1;
+				nd->mMeshes = new unsigned int[1];
+				nd->mMeshes[0] = static_cast<unsigned int>(meshes.size());
+				meshes.push_back(mesh);
+			}
+		}
+		else {
+			LogWarn("ignoring object: " + std::string(GetObjectTypeName(type)));
+		}
+		
+		RecurseHierarchy(object->GetDown(), nd);
+		object = object->GetNext();
+	}
+
+	// copy nodes over to parent
+	parent->mNumChildren = static_cast<unsigned int>(nodes.size());
+	parent->mChildren = new aiNode*[parent->mNumChildren]();
+	std::copy(nodes.begin(), nodes.end(), parent->mChildren);
+}
+
+
+// ------------------------------------------------------------------------------------------------
+aiMesh* C4DImporter::ReadMesh(BaseObject* object)
+{
+	assert(object != NULL && object->GetType() == Opolygon);
+
+	// based on Melange sample code
+	PolygonObject* const polyObject = dynamic_cast<PolygonObject*>(object);
+	ai_assert(polyObject != NULL);
+
+	const LONG pointCount = polyObject->GetPointCount();
+	const LONG polyCount = polyObject->GetPolygonCount();
+	if(!polyObject || !pointCount) {
+		LogWarn("ignoring mesh with zero vertices or faces");
+		return NULL;
+	}
+
+	const Vector* points = polyObject->GetPointR();
+	ai_assert(points != NULL);
+
+	const CPolygon* polys = polyObject->GetPolygonR();
+	ai_assert(polys != NULL);
+
+	ScopeGuard<aiMesh> mesh(new aiMesh());
+	mesh->mNumFaces = static_cast<unsigned int>(polyCount);
+	aiFace* face = mesh->mFaces = new aiFace[mesh->mNumFaces]();
+
+	mesh->mPrimitiveTypes = aiPrimitiveType_TRIANGLE;
+	mesh->mMaterialIndex = 0;
+
+	unsigned int vcount = 0;
+
+	// first count vertices
+	for (LONG i = 0; i < polyCount; i++)
+	{
+		vcount += 3;
+		
+		// TODO: do we also need to handle lines or points with similar checks?
+		if (polys[i].c != polys[i].d)
+		{
+			mesh->mPrimitiveTypes |= aiPrimitiveType_POLYGON;
+			++vcount;
+		}
+	}
+
+	ai_assert(vcount > 0);
+
+	mesh->mNumVertices = vcount;
+	aiVector3D* verts = mesh->mVertices = new aiVector3D[mesh->mNumVertices];
+	aiVector3D* normals, *uvs, *tangents, *bitangents;
+	unsigned int n = 0;
+
+	// check if there are normals, tangents or UVW coordinates
+	BaseTag* tag = object->GetTag(Tnormal);
+	NormalTag* normals_src = NULL;
+	if(tag) {
+		normals_src = dynamic_cast<NormalTag*>(tag);
+		normals = mesh->mNormals = new aiVector3D[mesh->mNumVertices]();
+	}
+
+	tag = object->GetTag(Ttangent);
+	TangentTag* tangents_src = NULL;
+	if(tag) {
+		tangents_src = dynamic_cast<TangentTag*>(tag);
+		tangents = mesh->mTangents = new aiVector3D[mesh->mNumVertices]();
+		bitangents = mesh->mBitangents = new aiVector3D[mesh->mNumVertices]();
+	}
+
+	tag = object->GetTag(Tuvw);
+	UVWTag* uvs_src = NULL;
+	if(tag) {
+		uvs_src = dynamic_cast<UVWTag*>(tag);
+		uvs = mesh->mTextureCoords[0] = new aiVector3D[mesh->mNumVertices]();
+	}
+
+	// copy vertices and extra channels over and populate faces
+	for (LONG i = 0; i < polyCount; ++i, ++face)
+	{
+		ai_assert(polys[i].a < pointCount && polys[i].a >= 0);
+		const Vector& pointA = points[polys[i].a];
+		verts->x = pointA.x;
+		verts->y = pointA.y;
+		verts->z = pointA.z;
+		++verts;
+
+		ai_assert(polys[i].b < pointCount && polys[i].b >= 0);
+		const Vector& pointB = points[polys[i].b];
+		verts->x = pointB.x;
+		verts->y = pointB.y;
+		verts->z = pointB.z;
+		++verts;
+
+		ai_assert(polys[i].c < pointCount && polys[i].c >= 0);
+		const Vector& pointC = points[polys[i].c];
+		verts->x = pointC.x;
+		verts->y = pointC.y;
+		verts->z = pointC.z;
+		++verts;
+
+		// TODO: do we also need to handle lines or points with similar checks?
+		if (polys[i].c != polys[i].d)
+		{
+			ai_assert(polys[i].d < pointCount && polys[i].d >= 0);
+
+			face->mNumIndices = 4;
+			mesh->mPrimitiveTypes |= aiPrimitiveType_POLYGON;
+			const Vector& pointD = points[polys[i].d];
+			verts->x = pointD.x;
+			verts->y = pointD.y;
+			verts->z = pointD.z;
+			++verts;
+		}
+		else {
+			face->mNumIndices = 3;
+		}
+		face->mIndices = new unsigned int[face->mNumIndices];
+		for(unsigned int j = 0; j < face->mNumIndices; ++j) {
+			face->mIndices[j] = n++;
+		}
+
+		// copy normals
+		if (normals_src) {
+			if(i >= normals_src->GetNormalCount()) {
+				LogError("unexpected number of normals, ignoring");
+			}
+			else {
+				const NormalStruct& nor = normals_src->GetNormals(i);
+				normals->x = nor.a.x;
+				normals->y = nor.a.y;
+				normals->z = nor.a.z;
+				++normals;
+
+				normals->x = nor.b.x;
+				normals->y = nor.b.y;
+				normals->z = nor.b.z;
+				++normals;
+
+				normals->x = nor.c.x;
+				normals->y = nor.c.y;
+				normals->z = nor.c.z;
+				++normals;
+
+				if(face->mNumIndices == 4) {
+					normals->x = nor.d.x;
+					normals->y = nor.d.y;
+					normals->z = nor.d.z;
+					++normals;
+				}
+			}
+		}
+
+		// copy tangents and bitangents
+		if (tangents_src) {
+			
+			for(unsigned int k = 0; k < face->mNumIndices; ++k) {
+				LONG l;
+				switch(k) {
+				case 0:
+					l = polys[i].a;
+					break;
+				case 1:
+					l = polys[i].b;
+					break;
+				case 2:
+					l = polys[i].c;
+					break;
+				case 3:
+					l = polys[i].d;
+					break;
+				default:
+					ai_assert(false);
+				}
+				if(l >= tangents_src->GetDataCount()) {
+					LogError("unexpected number of tangents, ignoring");
+					break;
+				}
+
+				Tangent tan = tangents_src->GetDataR()[l];
+				tangents->x = tan.vl.x;
+				tangents->y = tan.vl.y;
+				tangents->z = tan.vl.z;
+				++tangents;
+
+				bitangents->x = tan.vr.x;
+				bitangents->y = tan.vr.y;
+				bitangents->z = tan.vr.z;
+				++bitangents;
+			}
+		}
+
+		// copy UVs
+		if (uvs_src) {
+			if(i >= uvs_src->GetDataCount()) {
+				LogError("unexpected number of UV coordinates, ignoring");
+			}
+			else {
+				UVWStruct uvw;
+				uvs_src->Get(uvs_src->GetDataAddressR(),i,uvw);
+
+				uvs->x = uvw.a.x;
+				uvs->y = 1.0f-uvw.a.y;
+				uvs->z = uvw.a.z;
+				++uvs;
+
+				uvs->x = uvw.b.x;
+				uvs->y = 1.0f-uvw.b.y;
+				uvs->z = uvw.b.z;
+				++uvs;
+
+				uvs->x = uvw.c.x;
+				uvs->y = 1.0f-uvw.c.y;
+				uvs->z = uvw.c.z;
+				++uvs;
+
+				if(face->mNumIndices == 4) {
+					uvs->x = uvw.d.x;
+					uvs->y = 1.0f-uvw.d.y;
+					uvs->z = uvw.d.z;
+					++uvs;
+				}
+			}
+		}
+	}
+
+	mesh->mMaterialIndex = ResolveMaterial(polyObject);
+	return mesh.dismiss();
+}
+
+
+// ------------------------------------------------------------------------------------------------
+unsigned int C4DImporter::ResolveMaterial(PolygonObject* obj)
+{
+	ai_assert(obj != NULL);
+
+	const unsigned int mat_count = static_cast<unsigned int>(materials.size());
+
+	BaseTag* tag = obj->GetTag(Ttexture);
+	if(tag == NULL) {
+		return mat_count;
+	}
+
+	TextureTag& ttag = dynamic_cast<TextureTag&>(*tag);
+
+	BaseMaterial* const mat = ttag.GetMaterial();
+	assert(mat != NULL);
+
+	const MaterialMap::const_iterator it = material_mapping.find(mat);
+	if(it == material_mapping.end()) {
+		return mat_count;
+	}
+
+	ai_assert((*it).second < mat_count);
+	return (*it).second;
+}

code/C4DImporter.h

@@ -0,0 +1,120 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2012, 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  C4DImporter.h
+ *  @brief Declaration of the Cinema4D (*.c4d) importer class.
+ */
+#ifndef INCLUDED_AI_CINEMA_4D_LOADER_H
+#define INCLUDED_AI_CINEMA_4D_LOADER_H
+
+#include "BaseImporter.h"
+#include "LogAux.h"
+
+#include <set>
+
+struct aiImporterDesc;
+
+namespace _melange_ {
+	class BaseObject; // c4d_file.h
+	class PolygonObject;
+	class BaseMaterial;
+	class BaseShader;
+}
+
+namespace Assimp	{
+
+	// TinyFormatter.h
+	namespace Formatter {
+		template <typename T,typename TR, typename A> class basic_formatter;
+		typedef class basic_formatter< char, std::char_traits<char>, std::allocator<char> > format;
+	}
+
+// -------------------------------------------------------------------------------------------
+/** Importer class to load Cinema4D files using the Melange library to be obtained from
+ *  www.plugincafe.com
+ *
+ *  Note that Melange is not free software. */
+// -------------------------------------------------------------------------------------------
+class C4DImporter : public BaseImporter, public LogFunctions<C4DImporter>
+{
+public:
+
+	C4DImporter();
+	~C4DImporter();
+
+
+public:
+
+	// --------------------
+	bool CanRead( const std::string& pFile, IOSystem* pIOHandler,
+		bool checkSig) const;
+
+protected:
+
+	// --------------------
+	const aiImporterDesc* GetInfo () const;
+
+	// --------------------
+	void SetupProperties(const Importer* pImp);
+
+	// --------------------
+	void InternReadFile( const std::string& pFile, aiScene* pScene, 
+		IOSystem* pIOHandler);
+
+private:
+
+	void ReadMaterials(_melange_::BaseMaterial* mat);
+	void RecurseHierarchy(_melange_::BaseObject* object, aiNode* parent);
+	aiMesh* ReadMesh(_melange_::BaseObject* object);
+	unsigned int ResolveMaterial(_melange_::PolygonObject* obj);
+
+	bool ReadShader(aiMaterial* out, _melange_::BaseShader* shader);
+
+	std::vector<aiMesh*> meshes;
+	std::vector<aiMaterial*> materials;
+
+	typedef std::map<_melange_::BaseMaterial*, unsigned int> MaterialMap;
+	MaterialMap material_mapping;
+
+}; // !class C4DImporter
+
+} // end of namespace Assimp
+#endif // INCLUDED_AI_CINEMA_4D_LOADER_H
+

code/CMakeLists.txt

@@ -148,6 +148,14 @@ SET( Common_SRCS
 )
 SOURCE_GROUP(Common FILES ${Common_SRCS})
 
+IF ( ASSIMP_BUILD_NONFREE_C4D_IMPORTER )
+	SET( C4D_SRCS
+		C4DImporter.cpp
+		C4DImporter.h
+	)
+	SOURCE_GROUP( C4D FILES ${C4D_SRCS})
+ENDIF ( ASSIMP_BUILD_NONFREE_C4D_IMPORTER )
+
 SET( 3DS_SRCS
 	3DSConverter.cpp
 	3DSHelper.h
@@ -718,6 +726,11 @@ SET( assimp_src
 	AssimpPCH.cpp
 )
 
+IF (ASSIMP_BUILD_NONFREE_C4D_IMPORTER)
+	SET( assimp_src ${assimp_src} ${C4D_SRCS})
+	INCLUDE_DIRECTORIES(${C4D_INCLUDES})
+ENDIF (ASSIMP_BUILD_NONFREE_C4D_IMPORTER)
+
 #ADD_MSVC_PRECOMPILED_HEADER("AssimpPCH.h" "AssimpPCH.cpp" assimp_src)
 
 ADD_LIBRARY( assimp ${assimp_src} )
@@ -730,6 +743,12 @@ if(ANDROID AND ASSIMP_ANDROID_JNIIOSYSTEM)
 	target_link_libraries(assimp android_jniiosystem)
 endif(ANDROID AND ASSIMP_ANDROID_JNIIOSYSTEM)
 
+IF (ASSIMP_BUILD_NONFREE_C4D_IMPORTER)
+	TARGET_LINK_LIBRARIES(assimp optimized ${C4D_RELEASE_LIBRARY})
+	TARGET_LINK_LIBRARIES(assimp debug ${C4D_DEBUG_LIBRARY})
+	TARGET_LINK_LIBRARIES(assimp ${C4D_EXTRA_LIBRARIES})
+ENDIF (ASSIMP_BUILD_NONFREE_C4D_IMPORTER)
+
 if( MSVC )
   # in order to prevent DLL hell, each of the DLLs have to be suffixed with the major version and msvc prefix
   if( MSVC70 OR MSVC71 )

code/IFCBoolean.cpp

@@ -50,42 +50,97 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include "ProcessHelper.h"
 
 #include <iterator>
+#include <boost/tuple/tuple.hpp>
+
 
 namespace Assimp {
 	namespace IFC {
 		
 // ------------------------------------------------------------------------------------------------
-enum Intersect {
+// Calculates intersection between line segment and plane. To catch corner cases, specify which side you prefer.
-	Intersect_No,
+// The function then generates a hit only if the end is beyond a certain margin in that direction, filtering out
-	Intersect_LiesOnPlane,
+// "very close to plane" ghost hits as long as start and end stay directly on or within the given plane side.
-	Intersect_Yes
+bool IntersectSegmentPlane(const IfcVector3& p,const IfcVector3& n, const IfcVector3& e0, 
-};
+	const IfcVector3& e1, bool assumeStartOnWhiteSide, IfcVector3& out)
-
-// ------------------------------------------------------------------------------------------------
-Intersect IntersectSegmentPlane(const IfcVector3& p,const IfcVector3& n, const IfcVector3& e0, 
-								const IfcVector3& e1, 
-								IfcVector3& out) 
 {
-	const IfcVector3 pdelta = e0 - p, seg = e1-e0;
+	const IfcVector3 pdelta = e0 - p, seg = e1 - e0;
 	const IfcFloat dotOne = n*seg, dotTwo = -(n*pdelta);
 
-	if (std::fabs(dotOne) < 1e-6) {
+	// if segment ends on plane, do not report a hit. We stay on that side until a following segment starting at this
-		return std::fabs(dotTwo) < 1e-6f ? Intersect_LiesOnPlane : Intersect_No;
+	// point leaves the plane through the other side
+	if( std::abs(dotOne + dotTwo) < 1e-6 )
+		return false;
+
+	// if segment starts on the plane, report a hit only if the end lies on the *other* side
+	if( std::abs(dotTwo) < 1e-6 )
+	{
+		if( (assumeStartOnWhiteSide && dotOne + dotTwo < 1e-6) || (!assumeStartOnWhiteSide && dotOne + dotTwo > -1e-6) )
+		{
+			out = e0;
+			return true;
+		}
+		else
+		{
+			return false;
+		}
 	}
 
-	const IfcFloat t = dotTwo/dotOne;
+	// ignore if segment is parallel to plane and far away from it on either side
+	// Warning: if there's a few thousand of such segments which slowly accumulate beyond the epsilon, no hit would be registered
+	if( std::abs(dotOne) < 1e-6 )
+		return false;
+
 	// t must be in [0..1] if the intersection point is within the given segment
-	if (t > 1.f || t < 0.f) {
+	const IfcFloat t = dotTwo / dotOne;
-		return Intersect_No;
+	if( t > 1.0 || t < 0.0 )
-	}
+		return false;
-	out = e0+t*seg;
+
-	return Intersect_Yes;
+	out = e0 + t*seg;
+	return true;
 }
 
+// ------------------------------------------------------------------------------------------------
+void FilterPolygon(std::vector<IfcVector3>& resultpoly)
+{
+	if( resultpoly.size() < 3 )
+	{
+		resultpoly.clear();
+		return;
+	}
+
+	IfcVector3 vmin, vmax;
+	ArrayBounds(resultpoly.data(), resultpoly.size(), vmin, vmax);
+
+	// filter our IfcFloat points - those may happen if a point lies
+	// directly on the intersection line or directly on the clipping plane
+	const IfcFloat epsilon = (vmax - vmin).SquareLength() / 1e6f;
+	FuzzyVectorCompare fz(epsilon);
+	std::vector<IfcVector3>::iterator e = std::unique(resultpoly.begin(), resultpoly.end(), fz);
+
+	if( e != resultpoly.end() )
+		resultpoly.erase(e, resultpoly.end());
+
+	if( !resultpoly.empty() && fz(resultpoly.front(), resultpoly.back()) )
+		resultpoly.pop_back();
+}
+
+// ------------------------------------------------------------------------------------------------
+void WritePolygon(std::vector<IfcVector3>& resultpoly, TempMesh& result)
+{
+	FilterPolygon(resultpoly);
+
+	if( resultpoly.size() > 2 )
+	{
+		result.verts.insert(result.verts.end(), resultpoly.begin(), resultpoly.end());
+		result.vertcnt.push_back(resultpoly.size());
+	}
+}
+
+
 // ------------------------------------------------------------------------------------------------
 void ProcessBooleanHalfSpaceDifference(const IfcHalfSpaceSolid* hs, TempMesh& result,
-									   const TempMesh& first_operand, 
+	const TempMesh& first_operand,
-									   ConversionData& /*conv*/)
+	ConversionData& /*conv*/)
 {
 	ai_assert(hs != NULL);
 
@@ -120,20 +175,14 @@ void ProcessBooleanHalfSpaceDifference(const IfcHalfSpaceSolid* hs, TempMesh& re
 	for(iit = begin; iit != end; vidx += *iit++) {
 
 		unsigned int newcount = 0;
-		for(unsigned int i = 0; i < *iit; ++i) {
+		bool isAtWhiteSide = (in[vidx] - p) * n > -1e-6;
-			const IfcVector3& e0 = in[vidx+i], e1 = in[vidx+(i+1)%*iit];
+		for( unsigned int i = 0; i < *iit; ++i ) {
+			const IfcVector3& e0 = in[vidx + i], e1 = in[vidx + (i + 1) % *iit];
 
 			// does the next segment intersect the plane?
 			IfcVector3 isectpos;
-			const Intersect isect = IntersectSegmentPlane(p,n,e0,e1,isectpos);
+			if( IntersectSegmentPlane(p, n, e0, e1, isAtWhiteSide, isectpos) ) {
-			if (isect == Intersect_No || isect == Intersect_LiesOnPlane) {
+				if( isAtWhiteSide ) {
-				if ( (e0-p).Normalize()*n > 0 ) {
-					outvert.push_back(e0);
-					++newcount;
-				}
-			}
-			else if (isect == Intersect_Yes) {
-				if ( (e0-p).Normalize()*n > 0 ) {
 					// e0 is on the right side, so keep it 
 					outvert.push_back(e0);
 					outvert.push_back(isectpos);
@@ -144,6 +193,14 @@ void ProcessBooleanHalfSpaceDifference(const IfcHalfSpaceSolid* hs, TempMesh& re
 					outvert.push_back(isectpos);
 					++newcount;
 				}
+				isAtWhiteSide = !isAtWhiteSide;
+			}
+			else
+			{
+				if( isAtWhiteSide ) {
+					outvert.push_back(e0);
+					++newcount;
+				}
 			}
 		}
 
@@ -185,76 +242,114 @@ void ProcessBooleanHalfSpaceDifference(const IfcHalfSpaceSolid* hs, TempMesh& re
 // ------------------------------------------------------------------------------------------------
 // Check if e0-e1 intersects a sub-segment of the given boundary line.
 // note: this functions works on 3D vectors, but performs its intersection checks solely in xy.
-bool IntersectsBoundaryProfile( const IfcVector3& e0, const IfcVector3& e1, const std::vector<IfcVector3>& boundary,
+// New version takes the supposed inside/outside state as a parameter and treats corner cases as if
-	std::vector<size_t>& intersected_boundary_segments,
+// the line stays on that side. This should make corner cases more stable.
-	std::vector<IfcVector3>& intersected_boundary_points,
+// Two million assumptions! Boundary should have all z at 0.0, will be treated as closed, should not have
-	bool half_open = false,
+// segments with length <1e-6, self-intersecting might break the corner case handling... just don't go there, ok?
-	bool* e0_hits_border = NULL)
+bool IntersectsBoundaryProfile(const IfcVector3& e0, const IfcVector3& e1, const std::vector<IfcVector3>& boundary,
+	const bool isStartAssumedInside, std::vector<std::pair<size_t, IfcVector3> >& intersect_results,
+	const bool halfOpen = false)
 {
-	ai_assert(intersected_boundary_segments.empty());
+	ai_assert(intersect_results.empty());
-	ai_assert(intersected_boundary_points.empty());
 
-	if(e0_hits_border) {
+	// determine winding order - necessary to detect segments going "inwards" or "outwards" from a point directly on the border
-		*e0_hits_border = false;
+	// positive sum of angles means clockwise order when looking down the -Z axis
+	IfcFloat windingOrder = 0.0;
+	for( size_t i = 0, bcount = boundary.size(); i < bcount; ++i ) {
+		IfcVector3 b01 = boundary[(i + 1) % bcount] - boundary[i];
+		IfcVector3 b12 = boundary[(i + 2) % bcount] - boundary[(i + 1) % bcount];
+		IfcVector3 b1_side = IfcVector3(b01.y, -b01.x, 0.0); // rotated 90° clockwise in Z plane
+		// Warning: rough estimate only. A concave poly with lots of small segments each featuring a small counter rotation
+		// could fool the accumulation. Correct implementation would be sum( acos( b01 * b2) * sign( b12 * b1_side))
+		windingOrder += (b1_side.x*b12.x + b1_side.y*b12.y);
 	}
+	windingOrder = windingOrder > 0.0 ? 1.0 : -1.0;
 
-	const IfcVector3& e = e1 - e0;
+	const IfcVector3 e = e1 - e0;
 
-	for (size_t i = 0, bcount = boundary.size(); i < bcount; ++i) {
+	for( size_t i = 0, bcount = boundary.size(); i < bcount; ++i ) {
 		// boundary segment i: b0-b1
 		const IfcVector3& b0 = boundary[i];
-		const IfcVector3& b1 = boundary[(i+1) % bcount];
+		const IfcVector3& b1 = boundary[(i + 1) % bcount];
-
+		IfcVector3 b = b1 - b0;
-		const IfcVector3& b = b1 - b0;
+		IfcFloat b_sqlen_inv = 1.0 / b.SquareLength();
 
 		// segment-segment intersection
 		// solve b0 + b*s = e0 + e*t for (s,t)
 		const IfcFloat det = (-b.x * e.y + e.x * b.y);
-		if(std::fabs(det) < 1e-6) {
+		if( std::abs(det) < 1e-6 ) {
 			// no solutions (parallel lines)
 			continue;
 		}
 
 		const IfcFloat x = b0.x - e0.x;
 		const IfcFloat y = b0.y - e0.y;
-
+		const IfcFloat s = (x*e.y - e.x*y) / det; // scale along boundary edge
-		const IfcFloat s = (x*e.y - e.x*y)/det;
+		const IfcFloat t = (x*b.y - b.x*y) / det; // scale along given segment
-		const IfcFloat t = (x*b.y - b.x*y)/det;
+		const IfcVector3 p = e0 + e*t;
-
 #ifdef ASSIMP_BUILD_DEBUG
-		const IfcVector3 check = b0 + b*s  - (e0 + e*t);
+		const IfcVector3 check = b0 + b*s - p;
-		ai_assert((IfcVector2(check.x,check.y)).SquareLength() < 1e-5);
+		ai_assert((IfcVector2(check.x, check.y)).SquareLength() < 1e-5);
 #endif
 
-		// for a valid intersection, s-t should be in range [0,1].
+		// also calculate the distance of e0 and e1 to the segment. We need to detect the "starts directly on segment" 
-		// note that for t (i.e. the segment point) we only use a
+		// and "ends directly at segment" cases
-		// half-sided epsilon because the next segment should catch
+		bool startsAtSegment, endsAtSegment;
-		// this case.
+		{
-		const IfcFloat epsilon = 1e-6;
+			// calculate closest point to each end on the segment, clamp that point to the segment's length, then check
-		if (t >= -epsilon && (t <= 1.0+epsilon || half_open) && s >= -epsilon && s <= 1.0) {
+			// distance to that point. This approach is like testing if e0 is inside a capped cylinder.
+			IfcFloat et0 = (b.x*(e0.x - b0.x) + b.y*(e0.y - b0.y)) * b_sqlen_inv;
+			IfcVector3 closestPosToE0OnBoundary = b0 + std::max(IfcFloat(0.0), std::min(IfcFloat(1.0), et0)) * b;
+			startsAtSegment = (closestPosToE0OnBoundary - IfcVector3(e0.x, e0.y, 0.0)).SquareLength() < 1e-12;
+			IfcFloat et1 = (b.x*(e1.x - b0.x) + b.y*(e1.y - b0.y)) * b_sqlen_inv;
+			IfcVector3 closestPosToE1OnBoundary = b0 + std::max(IfcFloat(0.0), std::min(IfcFloat(1.0), et1)) * b;
+			endsAtSegment = (closestPosToE1OnBoundary - IfcVector3(e1.x, e1.y, 0.0)).SquareLength() < 1e-12;
+		}
 
-			if (e0_hits_border && !*e0_hits_border) {
+		// Line segment ends at boundary -> ignore any hit, it will be handled by possibly following segments
-				*e0_hits_border = std::fabs(t) < 1e-5f;
+		if( endsAtSegment && !halfOpen )
-			}
+			continue;
 
-			const IfcVector3& p = e0 + e*t;
+		// Line segment starts at boundary -> generate a hit only if following that line would change the INSIDE/OUTSIDE
+		// state. This should catch the case where a connected set of segments has a point directly on the boundary,
+		// one segment not hitting it because it ends there and the next segment not hitting it because it starts there
+		// Should NOT generate a hit if the segment only touches the boundary but turns around and stays inside.
+		if( startsAtSegment )
+		{
+			IfcVector3 inside_dir = IfcVector3(b.y, -b.x, 0.0) * windingOrder;
+			bool isGoingInside = (inside_dir * e) > 0.0;
+			if( isGoingInside == isStartAssumedInside )
+				continue;
 
-			// only insert the point into the list if it is sufficiently
+			// only insert the point into the list if it is sufficiently far away from the previous intersection point. 
-			// far away from the previous intersection point. This way,
+			// This way, we avoid duplicate detection if the intersection is directly on the vertex between two segments.
-			// we avoid duplicate detection if the intersection is
+			if( !intersect_results.empty() && intersect_results.back().first == i - 1 )
-			// directly on the vertex between two segments.
+			{
-			if (!intersected_boundary_points.empty() && intersected_boundary_segments.back()==i-1 ) {
+				const IfcVector3 diff = intersect_results.back().second - e0;
-				const IfcVector3 diff = intersected_boundary_points.back() - p;
+				if( IfcVector2(diff.x, diff.y).SquareLength() < 1e-10 )
-				if(IfcVector2(diff.x, diff.y).SquareLength() < 1e-7) {
 					continue;
-				}
 			}
-			intersected_boundary_segments.push_back(i);
+			intersect_results.push_back(std::make_pair(i, e0));
-			intersected_boundary_points.push_back(p);
+			continue;
+		}
+
+		// for a valid intersection, s and t should be in range [0,1]. Including a bit of epsilon on s, potential double
+		// hits on two consecutive boundary segments are filtered
+		if( s >= -1e-6 * b_sqlen_inv && s <= 1.0 + 1e-6*b_sqlen_inv && t >= 0.0 && (t <= 1.0 || halfOpen) )
+		{
+			// only insert the point into the list if it is sufficiently far away from the previous intersection point. 
+			// This way, we avoid duplicate detection if the intersection is directly on the vertex between two segments.
+			if( !intersect_results.empty() && intersect_results.back().first == i - 1 )
+			{
+				const IfcVector3 diff = intersect_results.back().second - p;
+				if( IfcVector2(diff.x, diff.y).SquareLength() < 1e-10 )
+					continue;
+			}
+			intersect_results.push_back(std::make_pair(i, p));
 		}
 	}
 
-	return !intersected_boundary_segments.empty();
+	return !intersect_results.empty();
 }
 
 
@@ -272,47 +367,21 @@ bool PointInPoly(const IfcVector3& p, const std::vector<IfcVector3>& boundary)
 	// the border of the polygon. If any of our attempts produces this result,
 	// we return false immediately.
 
-	std::vector<size_t> intersected_boundary_segments;
+	std::vector<std::pair<size_t, IfcVector3> > intersected_boundary;
-	std::vector<IfcVector3> intersected_boundary_points;
 	size_t votes = 0;
 
-	bool is_border;
+	IntersectsBoundaryProfile(p, p + IfcVector3(1.0, 0, 0), boundary, true, intersected_boundary, true);
-	IntersectsBoundaryProfile(p, p + IfcVector3(1.0,0,0), boundary, 
+	votes += intersected_boundary.size() % 2;
-		intersected_boundary_segments, 
-		intersected_boundary_points, true, &is_border);
 
-	if(is_border) {
+	intersected_boundary.clear();
-		return false;
+	IntersectsBoundaryProfile(p, p + IfcVector3(0, 1.0, 0), boundary, true, intersected_boundary, true);
-	}
+	votes += intersected_boundary.size() % 2;
 
-	votes += intersected_boundary_segments.size() % 2;
+	intersected_boundary.clear();
+	IntersectsBoundaryProfile(p, p + IfcVector3(0.6, -0.6, 0.0), boundary, true, intersected_boundary, true);
+	votes += intersected_boundary.size() % 2;
 
-	intersected_boundary_segments.clear();
+	ai_assert(votes == 3 || votes == 0);
-	intersected_boundary_points.clear();
-
-	IntersectsBoundaryProfile(p, p + IfcVector3(0,1.0,0), boundary, 
-		intersected_boundary_segments, 
-		intersected_boundary_points, true, &is_border);
-
-	if(is_border) {
-		return false;
-	}
-
-	votes += intersected_boundary_segments.size() % 2;
-
-	intersected_boundary_segments.clear();
-	intersected_boundary_points.clear();
-
-	IntersectsBoundaryProfile(p, p + IfcVector3(0.6,-0.6,0.0), boundary, 
-		intersected_boundary_segments, 
-		intersected_boundary_points, true, &is_border);
-
-	if(is_border) {
-		return false;
-	}
-
-	votes += intersected_boundary_segments.size() % 2;
-	//ai_assert(votes == 3 || votes == 0);
 	return votes > 1;
 }
 
@@ -350,6 +419,9 @@ void ProcessPolygonalBoundedBooleanHalfSpaceDifference(const IfcPolygonalBounded
 		return;
 	}
 
+	// determine winding order by calculating the normal.
+	IfcVector3 profileNormal = TempMesh::ComputePolygonNormal(profile->verts.data(), profile->verts.size());
+
 	IfcMatrix4 proj_inv;
 	ConvertAxisPlacement(proj_inv,hs->Position);
 
@@ -361,256 +433,283 @@ void ProcessPolygonalBoundedBooleanHalfSpaceDifference(const IfcPolygonalBounded
 	// clip the current contents of `meshout` against the plane we obtained from the second operand
 	const std::vector<IfcVector3>& in = first_operand.verts;
 	std::vector<IfcVector3>& outvert = result.verts;
-
+	std::vector<unsigned int>& outvertcnt = result.vertcnt;
-	std::vector<unsigned int>::const_iterator begin = first_operand.vertcnt.begin(), 
-		end = first_operand.vertcnt.end(), iit;
 
 	outvert.reserve(in.size());
-	result.vertcnt.reserve(first_operand.vertcnt.size());
+	outvertcnt.reserve(first_operand.vertcnt.size());
 
-	std::vector<size_t> intersected_boundary_segments;
-	std::vector<IfcVector3> intersected_boundary_points;
-
-	// TODO: the following algorithm doesn't handle all cases. 
 	unsigned int vidx = 0;
-	for(iit = begin; iit != end; vidx += *iit++) {
+	std::vector<unsigned int>::const_iterator begin = first_operand.vertcnt.begin();
-		if (!*iit) {
+	std::vector<unsigned int>::const_iterator end = first_operand.vertcnt.end();
-			continue;
+	std::vector<unsigned int>::const_iterator iit;
+	for( iit = begin; iit != end; vidx += *iit++ )
+	{
+		// Our new approach: we cut the poly along the plane, then we intersect the part on the black side of the plane 
+		// against the bounding polygon. All the white parts, and the black part outside the boundary polygon, are kept.
+		std::vector<IfcVector3> whiteside, blackside;
+
+		{
+			const IfcVector3* srcVertices = &in[vidx];
+			const size_t srcVtxCount = *iit;
+			if( srcVtxCount == 0 )
+				continue;
+
+			IfcVector3 polyNormal = TempMesh::ComputePolygonNormal(srcVertices, srcVtxCount, true);
+			polyNormal = IfcMatrix3(proj) * polyNormal;
+
+			// if the poly is parallel to the plane, put it completely on the black or white side
+			if( std::abs(polyNormal * n) > 0.9999 )
+			{
+				bool isOnWhiteSide = ((proj * srcVertices[0]) - p) * n > -1e-6;
+				std::vector<IfcVector3>& targetSide = isOnWhiteSide ? whiteside : blackside;
+				targetSide.insert(targetSide.end(), srcVertices, srcVertices + srcVtxCount);
+			}
+			else
+			{
+				// otherwise start building one polygon for each side. Whenever the current line segment intersects the plane
+				// we put a point there as an end of the current segment. Then we switch to the other side, put a point there, too,
+				// as a beginning of the current segment, and simply continue accumulating vertices. 
+				bool isCurrentlyOnWhiteSide = ((proj * srcVertices[0]) - p) * n > -1e-6;
+				for( size_t a = 0; a < srcVtxCount; ++a )
+				{
+					IfcVector3 e0 = proj * srcVertices[a];
+					IfcVector3 e1 = proj * srcVertices[(a + 1) % srcVtxCount];
+					IfcVector3 ei;
+
+					// put starting point to the current mesh
+					std::vector<IfcVector3>& trgt = isCurrentlyOnWhiteSide ? whiteside : blackside;
+					trgt.push_back(srcVertices[a]);
+
+					// if there's an intersection, put an end vertex there, switch to the other side's mesh,
+					// and add a starting vertex there, too
+					bool isPlaneHit = IntersectSegmentPlane(p, n, e0, e1, isCurrentlyOnWhiteSide, ei);
+					if( isPlaneHit )
+					{
+						IfcVector3 global_ei = proj_inv * ei;
+						if( trgt.empty() || (trgt.back() - global_ei).SquareLength() > 1e-12 )
+							trgt.push_back(global_ei);
+						isCurrentlyOnWhiteSide = !isCurrentlyOnWhiteSide;
+						std::vector<IfcVector3>& newtrgt = isCurrentlyOnWhiteSide ? whiteside : blackside;
+						newtrgt.push_back(global_ei);
+					}
+				}
+			}
 		}
 
-		unsigned int newcount = 0;
+		// the part on the white side can be written into the target mesh right away
-		bool was_outside_boundary = !PointInPoly(proj * in[vidx], profile->verts);
+		WritePolygon(whiteside, result);
 
-		// used any more?
+		// The black part is the piece we need to get rid of, but only the part of it within the boundary polygon.
-		//size_t last_intersected_boundary_segment;
+		// So we now need to construct all the polygons that result from BlackSidePoly minus BoundaryPoly.
-		IfcVector3 last_intersected_boundary_point;
+		FilterPolygon(blackside);
 
-		bool extra_point_flag = false;
+		// Complicated, II. We run along the polygon. a) When we're inside the boundary, we run on until we hit an 
-		IfcVector3 extra_point;
+		// intersection, which means we're leaving it. We then start a new out poly there. b) When we're outside the 
+		// boundary, we start collecting vertices until we hit an intersection, then we run along the boundary until we hit 
+		// an intersection, then we switch back to the poly and run on on this one again, and so on until we got a closed 
+		// loop. Then we continue with the path we left to catch potential additional polys on the other side of the 
+		// boundary as described in a)
+		if( !blackside.empty() )
+		{
+			// poly edge index, intersection point, edge index in boundary poly
+			std::vector<boost::tuple<size_t, IfcVector3, size_t> > intersections;
+			bool startedInside = PointInPoly(proj * blackside.front(), profile->verts);
+			bool isCurrentlyInside = startedInside;
 
-		IfcVector3 enter_volume;
+			std::vector<std::pair<size_t, IfcVector3> > intersected_boundary;
-		bool entered_volume_flag = false;
 
-		for(unsigned int i = 0; i < *iit; ++i) {
+			for( size_t a = 0; a < blackside.size(); ++a )
-			// current segment: [i,i+1 mod size] or [*extra_point,i] if extra_point_flag is set
+			{
-			const IfcVector3& e0 = extra_point_flag ? extra_point : in[vidx+i];
+				const IfcVector3 e0 = proj * blackside[a];
-			const IfcVector3& e1 = extra_point_flag ? in[vidx+i] : in[vidx+(i+1)%*iit];
+				const IfcVector3 e1 = proj * blackside[(a + 1) % blackside.size()];
 
-			// does the current segment intersect the polygonal boundary?
+				intersected_boundary.clear();
-			const IfcVector3& e0_plane = proj * e0;
+				IntersectsBoundaryProfile(e0, e1, profile->verts, isCurrentlyInside, intersected_boundary);
-			const IfcVector3& e1_plane = proj * e1;
+				// sort the hits by distance from e0 to get the correct in/out/in sequence. Manually :-( I miss you, C++11.
-
+				if( intersected_boundary.size() > 1 )
-			intersected_boundary_segments.clear();
+				{
-			intersected_boundary_points.clear();
+					bool keepSorting = true;
-
+					while( keepSorting )
-			const bool is_outside_boundary = !PointInPoly(e1_plane, profile->verts);
+					{
-			const bool is_boundary_intersection = is_outside_boundary != was_outside_boundary;
+						keepSorting = false;
-			
+						for( size_t b = 0; b < intersected_boundary.size() - 1; ++b )
-			IntersectsBoundaryProfile(e0_plane, e1_plane, profile->verts, 
+						{
-				intersected_boundary_segments, 
+							if( (intersected_boundary[b + 1].second - e0).SquareLength() < (intersected_boundary[b].second - e0).SquareLength() )
-				intersected_boundary_points);
+							{
-		
+								keepSorting = true;
-			ai_assert(!is_boundary_intersection || !intersected_boundary_segments.empty());
+								std::swap(intersected_boundary[b + 1], intersected_boundary[b]);
-
+							}
-			// does the current segment intersect the plane?
+						}
-			// (no extra check if this is an extra point)
-			IfcVector3 isectpos;
-			const Intersect isect =  extra_point_flag ? Intersect_No : IntersectSegmentPlane(p,n,e0,e1,isectpos);
-
-#ifdef ASSIMP_BUILD_DEBUG
-			if (isect == Intersect_Yes) {
-				const IfcFloat f = std::fabs((isectpos - p)*n);
-				ai_assert(f < 1e-5);
-			}
-#endif
-
-			const bool is_white_side = (e0-p)*n >= -1e-6;
-
-			// e0 on good side of plane? (i.e. we should keep all geometry on this side)
-			if (is_white_side) {
-				// but is there an intersection in e0-e1 and is e1 in the clipping
-				// boundary? In this case, generate a line that only goes to the
-				// intersection point.
-				if (isect == Intersect_Yes  && !is_outside_boundary) {
-					outvert.push_back(e0);
-					++newcount;
-
-					outvert.push_back(isectpos);
-					++newcount;
-					
-					/*
-					// this is, however, only a line that goes to the plane, but not
-					// necessarily to the point where the bounding volume on the
-					// black side of the plane is hit. So basically, we need another 
-					// check for [isectpos-e1], which should yield an intersection
-					// point.
-					extra_point_flag = true;
-					extra_point = isectpos;
-
-					was_outside_boundary = true; 
-					continue; */
-
-					// [isectpos, enter_volume] potentially needs extra points.
-					// For this, we determine the intersection point with the
-					// bounding volume and project it onto the plane. 
-					/*
-					const IfcVector3& enter_volume_proj = proj * enter_volume;
-					const IfcVector3& enter_isectpos = proj * isectpos;
-
-					intersected_boundary_segments.clear();
-					intersected_boundary_points.clear();
-
-					IntersectsBoundaryProfile(enter_volume_proj, enter_isectpos, profile->verts, 
-						intersected_boundary_segments, 
-						intersected_boundary_points);
-
-					if(!intersected_boundary_segments.empty()) {
-
-						vec = vec + ((p - vec) * n) * n;
 					}
-					*/				
-
-					//entered_volume_flag = true;
 				}
-				else {
+				// now add them to the list of intersections
-					outvert.push_back(e0);
+				for( size_t b = 0; b < intersected_boundary.size(); ++b )
-					++newcount;
+					intersections.push_back(boost::make_tuple(a, proj_inv * intersected_boundary[b].second, intersected_boundary[b].first));
+
+				// and calculate our new inside/outside state
+				if( intersected_boundary.size() & 1 )
+					isCurrentlyInside = !isCurrentlyInside;
+			}
+
+			// we got a list of in-out-combinations of intersections. That should be an even number of intersections, or
+			// we're fucked.
+			if( (intersections.size() & 1) != 0 )
+			{
+				IFCImporter::LogWarn("Odd number of intersections, can't work with that. Omitting half space boundary check.");
+				continue;
+			}
+
+			if( intersections.size() > 1 )
+			{
+				// If we started outside, the first intersection is a out->in intersection. Cycle them so that it
+				// starts with an intersection leaving the boundary
+				if( !startedInside )
+				for( size_t b = 0; b < intersections.size() - 1; ++b )
+					std::swap(intersections[b], intersections[(b + intersections.size() - 1) % intersections.size()]);
+
+				// Filter pairs of out->in->out that lie too close to each other. 
+				for( size_t a = 0; intersections.size() > 0 && a < intersections.size() - 1; /**/ )
+				{
+					if( (intersections[a].get<1>() - intersections[(a + 1) % intersections.size()].get<1>()).SquareLength() < 1e-10 )
+						intersections.erase(intersections.begin() + a, intersections.begin() + a + 2);
+					else
+						a++;
+				}
+				if( intersections.size() > 1 && (intersections.back().get<1>() - intersections.front().get<1>()).SquareLength() < 1e-10 )
+				{
+					intersections.pop_back(); intersections.erase(intersections.begin());
 				}
 			}
-			// e0 on bad side of plane, e1 on good (i.e. we should remove geometry on this side,
-			// but only if it is within the bounding volume).
-			else if (isect == Intersect_Yes) {
-				// is e0 within the clipping volume? Insert the intersection point
-				// of [e0,e1] and the plane instead of e0.
-				if(was_outside_boundary) {
-					outvert.push_back(e0);
-				}
-				else {
-					if(entered_volume_flag) {
-						const IfcVector3& fix_point = enter_volume + ((p - enter_volume) * n) * n;
-						outvert.push_back(fix_point);
-						++newcount;
-					}
 
-					outvert.push_back(isectpos);	
+
+			// no intersections at all: either completely inside the boundary, so everything gets discarded, or completely outside.
+			// in the latter case we're implementional lost. I'm simply going to ignore this, so a large poly will not get any
+			// holes if the boundary is smaller and does not touch it anywhere.
+			if( intersections.empty() )
+			{
+				// starting point was outside -> everything is outside the boundary -> nothing is clipped -> add black side 
+				// to result mesh unchanged
+				if( !startedInside )
+				{
+					outvertcnt.push_back(blackside.size());
+					outvert.insert(outvert.end(), blackside.begin(), blackside.end());
+					continue;
+				}
+				else
+				{
+					// starting point was inside the boundary -> everything is inside the boundary -> nothing is spared from the 
+					// clipping -> nothing left to add to the result mesh
+					continue;
 				}
-				entered_volume_flag = false;
-				++newcount;
 			}
-			else { // no intersection with plane or parallel; e0,e1 are on the bad side
 
-				// did we just pass the boundary line to the poly bounding?
+			// determine the direction in which we're marching along the boundary polygon. If the src poly is faced upwards
-				if (is_boundary_intersection) {
+			// and the boundary is also winded this way, we need to march *backwards* on the boundary.
+			const IfcVector3 polyNormal = IfcMatrix3(proj) * TempMesh::ComputePolygonNormal(blackside.data(), blackside.size());
+			bool marchBackwardsOnBoundary = (profileNormal * polyNormal) >= 0.0;
 
-					// and are now outside the clipping boundary?
+			// Build closed loops from these intersections. Starting from an intersection leaving the boundary we
-					if (is_outside_boundary) {
+			// walk along the polygon to the next intersection (which should be an IS entering the boundary poly).
-						// in this case, get the point where the clipping boundary
+			// From there we walk along the boundary until we hit another intersection leaving the boundary,
-						// was entered first. Then, get the point where the clipping
+			// walk along the poly to the next IS and so on until we're back at the starting point.
-						// boundary volume was left! These two points with the plane
+			// We remove every intersection we "used up", so any remaining intersection is the start of a new loop.
-						// normal form another plane that intersects the clipping
+			while( !intersections.empty() )
-						// volume. There are two ways to get from the first to the
+			{
-						// second point along the intersection curve, try to pick the
+				std::vector<IfcVector3> resultpoly;
-						// one that lies within the current polygon.
+				size_t currentIntersecIdx = 0;
 
-						// TODO this approach doesn't handle all cases
+				while( true )
+				{
+					ai_assert(intersections.size() > currentIntersecIdx + 1);
+					boost::tuple<size_t, IfcVector3, size_t> currintsec = intersections[currentIntersecIdx + 0];
+					boost::tuple<size_t, IfcVector3, size_t> nextintsec = intersections[currentIntersecIdx + 1];
+					intersections.erase(intersections.begin() + currentIntersecIdx, intersections.begin() + currentIntersecIdx + 2);
 
-						// ...
+					// we start with an in->out intersection
+					resultpoly.push_back(currintsec.get<1>());
+					// climb along the polygon to the next intersection, which should be an out->in
+					size_t numPolyPoints = (currintsec.get<0>() > nextintsec.get<0>() ? blackside.size() : 0)
+						+ nextintsec.get<0>() - currintsec.get<0>();
+					for( size_t a = 1; a <= numPolyPoints; ++a )
+						resultpoly.push_back(blackside[(currintsec.get<0>() + a) % blackside.size()]);
+					// put the out->in intersection 
+					resultpoly.push_back(nextintsec.get<1>());
 
-						IfcFloat d = 1e20;
+					// generate segments along the boundary polygon that lie in the poly's plane until we hit another intersection
-						IfcVector3 vclosest;
+					IfcVector3 startingPoint = proj * nextintsec.get<1>();
-						BOOST_FOREACH(const IfcVector3& v, intersected_boundary_points) {
+					size_t currentBoundaryEdgeIdx = (nextintsec.get<2>() + (marchBackwardsOnBoundary ? 1 : 0)) % profile->verts.size();
-							const IfcFloat dn = (v-e1_plane).SquareLength();
+					size_t nextIntsecIdx = SIZE_MAX;
-							if (dn < d) {
+					while( nextIntsecIdx == SIZE_MAX )
-								d = dn;
+					{
-								vclosest = v;
+						IfcFloat t = 1e10;
+
+						size_t nextBoundaryEdgeIdx = marchBackwardsOnBoundary ? (currentBoundaryEdgeIdx + profile->verts.size() - 1) : currentBoundaryEdgeIdx + 1;
+						nextBoundaryEdgeIdx %= profile->verts.size();
+						// vertices of the current boundary segments
+						IfcVector3 currBoundaryPoint = profile->verts[currentBoundaryEdgeIdx];
+						IfcVector3 nextBoundaryPoint = profile->verts[nextBoundaryEdgeIdx];
+
+						// build a direction that goes along the boundary border but lies in the poly plane
+						IfcVector3 boundaryPlaneNormal = ((nextBoundaryPoint - currBoundaryPoint) ^ profileNormal).Normalize();
+						IfcVector3 dirAtPolyPlane = (boundaryPlaneNormal ^ polyNormal).Normalize() * (marchBackwardsOnBoundary ? -1.0 : 1.0);
+						// if we can project the direction to the plane, we can calculate a maximum marching distance along that dir
+						// until we finish that boundary segment and continue on the next 
+						if( std::abs(polyNormal.z) > 1e-5 )
+						{
+							t = std::min(t, (nextBoundaryPoint - startingPoint).Length() / std::abs(polyNormal.z));
+						}
+
+						// check if the direction hits the loop start - if yes, we got a poly to output
+						IfcVector3 dirToThatPoint = proj * resultpoly.front() - startingPoint;
+						IfcFloat tpt = dirToThatPoint * dirAtPolyPlane;
+						if( tpt > -1e-6 && tpt <= t && (dirToThatPoint - tpt * dirAtPolyPlane).SquareLength() < 1e-10 )
+						{
+							nextIntsecIdx = intersections.size(); // dirty hack to end marching along the boundary and signal the end of the loop
+							t = tpt;
+						}
+
+						// also check if the direction hits any in->out intersections earlier. If we hit one, we can switch back
+						// to marching along the poly border from that intersection point
+						for( size_t a = 0; a < intersections.size(); a += 2 )
+						{
+							dirToThatPoint = proj * intersections[a].get<1>() - startingPoint;
+							tpt = dirToThatPoint * dirAtPolyPlane;
+							if( tpt > -1e-6 && tpt <= t && (dirToThatPoint - tpt * dirAtPolyPlane).SquareLength() < 1e-10 )
+							{
+								nextIntsecIdx = a; // switch back to poly and march on from this in->out intersection
+								t = tpt;
 							}
 						}
 
-						vclosest = proj_inv * vclosest;
+						// if we keep marching on the boundary, put the segment end point to the result poly and well... keep marching
-						if(entered_volume_flag) {
+						if( nextIntsecIdx == SIZE_MAX )
-							const IfcVector3& fix_point = vclosest + ((p - vclosest) * n) * n;
+						{
-							outvert.push_back(fix_point);
+							resultpoly.push_back(proj_inv * nextBoundaryPoint);
-							++newcount;
+							currentBoundaryEdgeIdx = nextBoundaryEdgeIdx;
-
+							startingPoint = nextBoundaryPoint;
-							entered_volume_flag = false;
 						}
 
-						outvert.push_back(vclosest);
+						// quick endless loop check
-						++newcount;
+						if( resultpoly.size() > blackside.size() + profile->verts.size() )
-
+						{
-						//outvert.push_back(e1);
+							IFCImporter::LogError("Encountered endless loop while clipping polygon against poly-bounded half space.");
-						//++newcount;
+							break;
-					}
-					else {
-						entered_volume_flag = true;
-
-						// we just entered the clipping boundary. Record the point
-						// and the segment where we entered and also generate this point.
-						//last_intersected_boundary_segment = intersected_boundary_segments.front();
-						//last_intersected_boundary_point = intersected_boundary_points.front();
-
-						outvert.push_back(e0);
-						++newcount;
-
-						IfcFloat d = 1e20;
-						IfcVector3 vclosest;
-						BOOST_FOREACH(const IfcVector3& v, intersected_boundary_points) {
-							const IfcFloat dn = (v-e0_plane).SquareLength();
-							if (dn < d) {
-								d = dn;
-								vclosest = v;
-							}
 						}
-
-						enter_volume = proj_inv * vclosest;
-						outvert.push_back(enter_volume);
-						++newcount;
 					}
-				}				
-				// if not, we just keep the vertex
-				else if (is_outside_boundary) {
-					outvert.push_back(e0);
-					++newcount;
 
-					entered_volume_flag = false;
+					// we're back on the poly - if this is the intersection we started from, we got a closed loop.
+					if( nextIntsecIdx >= intersections.size() )
+					{
+						break;
+					}
+
+					// otherwise it's another intersection. Continue marching from there.
+					currentIntersecIdx = nextIntsecIdx;
 				}
+
+				WritePolygon(resultpoly, result);
 			}
-
-			was_outside_boundary = is_outside_boundary;
-			extra_point_flag = false;
 		}
-	
-		if (!newcount) {
-			continue;
-		}
-		
-		IfcVector3 vmin,vmax;
-		ArrayBounds(&*(outvert.end()-newcount),newcount,vmin,vmax);
-
-		// filter our IfcFloat points - those may happen if a point lies
-		// directly on the intersection line. However, due to IfcFloat
-		// precision a bitwise comparison is not feasible to detect
-		// this case.
-		const IfcFloat epsilon = (vmax-vmin).SquareLength() / 1e6f;
-		FuzzyVectorCompare fz(epsilon);
-
-		std::vector<IfcVector3>::iterator e = std::unique( outvert.end()-newcount, outvert.end(), fz );
-
-		if (e != outvert.end()) {
-			newcount -= static_cast<unsigned int>(std::distance(e,outvert.end()));
-			outvert.erase(e,outvert.end());
-		}
-		if (fz(*( outvert.end()-newcount),outvert.back())) {
-			outvert.pop_back();
-			--newcount;
-		} 
-		if(newcount > 2) {
-			result.vertcnt.push_back(newcount);
-		}
-		else while(newcount-->0) {
-			result.verts.pop_back();
-		}
-
 	}
 	IFCImporter::LogDebug("generating CSG geometry by plane clipping with polygonal bounding (IfcBooleanClippingResult)");	
 }

code/IFCGeometry.cpp

@@ -579,6 +579,11 @@ void ProcessExtrudedAreaSolid(const IfcExtrudedAreaSolid& solid, TempMesh& resul
 	IfcVector3 min = in[0];
 	dir *= IfcMatrix3(trafo);
 
+	// reverse profile polygon if it's winded in the wrong direction in relation to the extrusion direction
+	IfcVector3 profileNormal = TempMesh::ComputePolygonNormal( in.data(), in.size());
+	if( profileNormal * dir < 0.0 )
+		std::reverse( in.begin(), in.end());
+
 	std::vector<IfcVector3> nors;
 	const bool openings = !!conv.apply_openings && conv.apply_openings->size();
 	
@@ -619,9 +624,9 @@ void ProcessExtrudedAreaSolid(const IfcExtrudedAreaSolid& solid, TempMesh& resul
 		curmesh.vertcnt.push_back(4);
 		
 		out.push_back(in[i]);
-		out.push_back(in[i]+dir);
-		out.push_back(in[next]+dir);
 		out.push_back(in[next]);
+		out.push_back(in[next]+dir);
+		out.push_back(in[i]+dir);
 
 		if(openings) {
 			if((in[i]-in[next]).Length() > diag * 0.1 && GenerateOpenings(*conv.apply_openings,nors,temp,true, true, dir)) {
@@ -646,8 +651,12 @@ void ProcessExtrudedAreaSolid(const IfcExtrudedAreaSolid& solid, TempMesh& resul
 	if(has_area) {
 
 		for(size_t n = 0; n < 2; ++n) {
-			for(size_t i = size; i--; ) {
+			if( n > 0 ) {
-				out.push_back(in[i]+(n?dir:IfcVector3()));
+				for(size_t i = 0; i < size; ++i ) 
+					out.push_back(in[i]+dir);
+			} else {
+				for(size_t i = size; i--; )
+					out.push_back(in[i]);
 			}
 
 			curmesh.vertcnt.push_back(size);
@@ -699,10 +708,10 @@ void ProcessSweptAreaSolid(const IfcSweptAreaSolid& swept, TempMesh& meshout,
 }
 
 // ------------------------------------------------------------------------------------------------
-bool ProcessGeometricItem(const IfcRepresentationItem& geo, std::vector<unsigned int>& mesh_indices, 
+bool ProcessGeometricItem(const IfcRepresentationItem& geo, unsigned int matid, std::vector<unsigned int>& mesh_indices, 
 	ConversionData& conv)
 {
-	bool fix_orientation = true;
+	bool fix_orientation = false;
 	boost::shared_ptr< TempMesh > meshtmp = boost::make_shared<TempMesh>(); 
 	if(const IfcShellBasedSurfaceModel* shellmod = geo.ToPtr<IfcShellBasedSurfaceModel>()) {
 		BOOST_FOREACH(boost::shared_ptr<const IfcShell> shell,shellmod->SbsmBoundary) {
@@ -716,24 +725,27 @@ bool ProcessGeometricItem(const IfcRepresentationItem& geo, std::vector<unsigned
 				IFCImporter::LogWarn("unexpected type error, IfcShell ought to inherit from IfcConnectedFaceSet");
 			}
 		}
+		fix_orientation = true;
 	}
 	else  if(const IfcConnectedFaceSet* fset = geo.ToPtr<IfcConnectedFaceSet>()) {
 		ProcessConnectedFaceSet(*fset,*meshtmp.get(),conv);
+		fix_orientation = true;
 	}	
 	else  if(const IfcSweptAreaSolid* swept = geo.ToPtr<IfcSweptAreaSolid>()) {
 		ProcessSweptAreaSolid(*swept,*meshtmp.get(),conv);
 	}   
 	else  if(const IfcSweptDiskSolid* disk = geo.ToPtr<IfcSweptDiskSolid>()) {
 		ProcessSweptDiskSolid(*disk,*meshtmp.get(),conv);
-		fix_orientation = false;
 	}   
 	else if(const IfcManifoldSolidBrep* brep = geo.ToPtr<IfcManifoldSolidBrep>()) {
 		ProcessConnectedFaceSet(brep->Outer,*meshtmp.get(),conv);
+		fix_orientation = true;
 	} 
 	else if(const IfcFaceBasedSurfaceModel* surf = geo.ToPtr<IfcFaceBasedSurfaceModel>()) {
 		BOOST_FOREACH(const IfcConnectedFaceSet& fc, surf->FbsmFaces) {
 			ProcessConnectedFaceSet(fc,*meshtmp.get(),conv);
 		}
+		fix_orientation = true;
 	}  
 	else  if(const IfcBooleanResult* boolean = geo.ToPtr<IfcBooleanResult>()) {
 		ProcessBoolean(*boolean,*meshtmp.get(),conv);
@@ -777,7 +789,7 @@ bool ProcessGeometricItem(const IfcRepresentationItem& geo, std::vector<unsigned
 
 	aiMesh* const mesh = meshtmp->ToMesh();
 	if(mesh) {
-		mesh->mMaterialIndex = ProcessMaterials(geo,conv);
+		mesh->mMaterialIndex = matid; 
 		mesh_indices.push_back(conv.meshes.size());
 		conv.meshes.push_back(mesh);
 		return true;
@@ -807,10 +819,11 @@ void AssignAddedMeshes(std::vector<unsigned int>& mesh_indices,aiNode* nd,
 
 // ------------------------------------------------------------------------------------------------
 bool TryQueryMeshCache(const IfcRepresentationItem& item, 
-	std::vector<unsigned int>& mesh_indices, 
+	std::vector<unsigned int>& mesh_indices, unsigned int mat_index,
 	ConversionData& conv) 
 {
-	ConversionData::MeshCache::const_iterator it = conv.cached_meshes.find(&item);
+	ConversionData::MeshCacheIndex idx(&item, mat_index);
+	ConversionData::MeshCache::const_iterator it = conv.cached_meshes.find(idx);
 	if (it != conv.cached_meshes.end()) {
 		std::copy((*it).second.begin(),(*it).second.end(),std::back_inserter(mesh_indices));
 		return true;
@@ -820,21 +833,25 @@ bool TryQueryMeshCache(const IfcRepresentationItem& item,
 
 // ------------------------------------------------------------------------------------------------
 void PopulateMeshCache(const IfcRepresentationItem& item, 
-	const std::vector<unsigned int>& mesh_indices, 
+	const std::vector<unsigned int>& mesh_indices, unsigned int mat_index,
 	ConversionData& conv)
 {
-	conv.cached_meshes[&item] = mesh_indices;
+	ConversionData::MeshCacheIndex idx(&item, mat_index);
+	conv.cached_meshes[idx] = mesh_indices;
 }
 
 // ------------------------------------------------------------------------------------------------
-bool ProcessRepresentationItem(const IfcRepresentationItem& item, 
+bool ProcessRepresentationItem(const IfcRepresentationItem& item, unsigned int matid,
 	std::vector<unsigned int>& mesh_indices, 
 	ConversionData& conv)
 {
-	if (!TryQueryMeshCache(item,mesh_indices,conv)) {
+	// determine material
-		if(ProcessGeometricItem(item,mesh_indices,conv)) {
+	unsigned int localmatid = ProcessMaterials(item.GetID(), matid, conv, true);
+
+	if (!TryQueryMeshCache(item,mesh_indices,localmatid,conv)) {
+		if(ProcessGeometricItem(item,localmatid,mesh_indices,conv)) {
 			if(mesh_indices.size()) {
-				PopulateMeshCache(item,mesh_indices,conv);
+				PopulateMeshCache(item,mesh_indices,localmatid,conv);
 			}
 		}
 		else return false;

code/IFCLoader.cpp

@@ -428,7 +428,7 @@ void GetAbsTransform(aiMatrix4x4& out, const aiNode* nd, ConversionData& conv)
 }
 
 // ------------------------------------------------------------------------------------------------
-bool ProcessMappedItem(const IfcMappedItem& mapped, aiNode* nd_src, std::vector< aiNode* >& subnodes_src, ConversionData& conv)
+bool ProcessMappedItem(const IfcMappedItem& mapped, aiNode* nd_src, std::vector< aiNode* >& subnodes_src, unsigned int matid, ConversionData& conv)
 {
 	// insert a custom node here, the cartesian transform operator is simply a conventional transformation matrix
 	std::auto_ptr<aiNode> nd(new aiNode());
@@ -453,11 +453,12 @@ bool ProcessMappedItem(const IfcMappedItem& mapped, aiNode* nd_src, std::vector<
 		}
 	}
 
+	unsigned int localmatid = ProcessMaterials(mapped.GetID(),matid,conv,false);
 	const IfcRepresentation& repr = mapped.MappingSource->MappedRepresentation;
 
 	bool got = false;
 	BOOST_FOREACH(const IfcRepresentationItem& item, repr.Items) {
-		if(!ProcessRepresentationItem(item,meshes,conv)) {
+		if(!ProcessRepresentationItem(item,localmatid,meshes,conv)) {
 			IFCImporter::LogWarn("skipping mapped entity of type " + item.GetClassName() + ", no representations could be generated");
 		}
 		else got = true;
@@ -557,7 +558,11 @@ void ProcessProductRepresentation(const IfcProduct& el, aiNode* nd, std::vector<
 	if(!el.Representation) {
 		return;
 	}
+
+	// extract Color from metadata, if present
+	unsigned int matid = ProcessMaterials( el.GetID(), UINT32_MAX, conv, false);
 	std::vector<unsigned int> meshes;
+
 	// we want only one representation type, so bring them in a suitable order (i.e try those
 	// that look as if we could read them quickly at first). This way of reading
 	// representation is relatively generic and allows the concrete implementations
@@ -571,10 +576,10 @@ void ProcessProductRepresentation(const IfcProduct& el, aiNode* nd, std::vector<
 		bool res = false;
 		BOOST_FOREACH(const IfcRepresentationItem& item, repr->Items) {
 			if(const IfcMappedItem* const geo = item.ToPtr<IfcMappedItem>()) {
-				res = ProcessMappedItem(*geo,nd,subnodes,conv) || res;
+				res = ProcessMappedItem(*geo,nd,subnodes,matid,conv) || res;
 			}
 			else {
-				res = ProcessRepresentationItem(item,meshes,conv) || res;
+				res = ProcessRepresentationItem(item,matid,meshes,conv) || res;
 			}
 		}
 		// if we got something meaningful at this point, skip any further representations

code/IFCMaterial.cpp

@@ -132,45 +132,70 @@ void FillMaterial(aiMaterial* mat,const IFC::IfcSurfaceStyle* surf,ConversionDat
 }
 
 // ------------------------------------------------------------------------------------------------
-unsigned int ProcessMaterials(const IFC::IfcRepresentationItem& item, ConversionData& conv)
+unsigned int ProcessMaterials(uint64_t id, unsigned int prevMatId, ConversionData& conv, bool forceDefaultMat)
 {
-	if (conv.materials.empty()) {
+	STEP::DB::RefMapRange range = conv.db.GetRefs().equal_range(id);
-		aiString name;
-		std::auto_ptr<aiMaterial> mat(new aiMaterial());
-
-		name.Set("<IFCDefault>");
-		mat->AddProperty(&name,AI_MATKEY_NAME);
-
-		const aiColor4D col = aiColor4D(0.6f,0.6f,0.6f,1.0f);
-		mat->AddProperty(&col,1, AI_MATKEY_COLOR_DIFFUSE);
-
-		conv.materials.push_back(mat.release());
-	}
-
-	STEP::DB::RefMapRange range = conv.db.GetRefs().equal_range(item.GetID());
 	for(;range.first != range.second; ++range.first) {
 		if(const IFC::IfcStyledItem* const styled = conv.db.GetObject((*range.first).second)->ToPtr<IFC::IfcStyledItem>()) {
 			BOOST_FOREACH(const IFC::IfcPresentationStyleAssignment& as, styled->Styles) {
 				BOOST_FOREACH(boost::shared_ptr<const IFC::IfcPresentationStyleSelect> sel, as.Styles) {
 
-					if (const IFC::IfcSurfaceStyle* const surf =  sel->ResolveSelectPtr<IFC::IfcSurfaceStyle>(conv.db)) {
+					if( const IFC::IfcSurfaceStyle* const surf = sel->ResolveSelectPtr<IFC::IfcSurfaceStyle>(conv.db) ) {
+						// try to satisfy from cache
+						ConversionData::MaterialCache::iterator mit = conv.cached_materials.find(surf);
+						if( mit != conv.cached_materials.end() )
+							return mit->second;
+
+						// not found, create new material
 						const std::string side = static_cast<std::string>(surf->Side);
-						if (side != "BOTH") {
+						if( side != "BOTH" ) {
 							IFCImporter::LogWarn("ignoring surface side marker on IFC::IfcSurfaceStyle: " + side);
 						}
 
 						std::auto_ptr<aiMaterial> mat(new aiMaterial());
 
-						FillMaterial(mat.get(),surf,conv);
+						FillMaterial(mat.get(), surf, conv);
 
 						conv.materials.push_back(mat.release());
-						return conv.materials.size()-1;
+						unsigned int matindex = conv.materials.size() - 1;
-					}
+						conv.cached_materials[surf] = matindex;
-				}
+						return matindex;
 			}
 		}
 	}
-	return 0;
+		}
+	}
+
+	// no local material defined. If there's global one, use that instead
+	if( prevMatId != UINT32_MAX )
+		return prevMatId;
+
+	// we're still here - create an default material if required, or simply fail otherwise
+	if( !forceDefaultMat )
+		return UINT32_MAX;
+
+	aiString name;
+	name.Set("<IFCDefault>");
+	//  ConvertColorToString( color, name);
+
+	// look if there's already a default material with this base color
+	for( size_t a = 0; a < conv.materials.size(); ++a )
+	{
+		aiString mname;
+		conv.materials[a]->Get(AI_MATKEY_NAME, mname);
+		if( name == mname )
+			return (unsigned int)a;
+	}
+
+	// we're here, yet - no default material with suitable color available. Generate one
+	std::auto_ptr<aiMaterial> mat(new aiMaterial());
+	mat->AddProperty(&name,AI_MATKEY_NAME);
+
+	const aiColor4D col = aiColor4D( 0.6f, 0.6f, 0.6f, 1.0f); // aiColor4D( color.r, color.g, color.b, 1.0f);
+	mat->AddProperty(&col,1, AI_MATKEY_COLOR_DIFFUSE);
+
+	conv.materials.push_back(mat.release());
+	return (unsigned int) conv.materials.size() - 1;
 }
 
 } // ! IFC

code/IFCOpenings.cpp

@@ -902,6 +902,14 @@ size_t CloseWindows(ContourVector& contours,
 			curmesh.verts.reserve(curmesh.verts.size() + (*it).contour.size() * 4);
 			curmesh.vertcnt.reserve(curmesh.vertcnt.size() + (*it).contour.size());
 
+			// compare base poly normal and contour normal to detect if we need to reverse the face winding
+			IfcVector3 basePolyNormal = TempMesh::ComputePolygonNormal( curmesh.verts.data(), curmesh.vertcnt.front());
+			std::vector<IfcVector3> worldSpaceContourVtx( it->contour.size());
+			for( size_t a = 0; a < it->contour.size(); ++a )
+				worldSpaceContourVtx[a] = minv * IfcVector3( it->contour[a].x, it->contour[a].y, 0.0);
+			IfcVector3 contourNormal = TempMesh::ComputePolygonNormal( worldSpaceContourVtx.data(), worldSpaceContourVtx.size());
+			bool reverseCountourFaces = (contourNormal * basePolyNormal) > 0.0;
+
 			// XXX this algorithm is really a bit inefficient - both in terms
 			// of constant factor and of asymptotic runtime.
 			std::vector<bool>::const_iterator skipit = skipbegin;
@@ -909,9 +917,6 @@ size_t CloseWindows(ContourVector& contours,
 			IfcVector3 start0;
 			IfcVector3 start1;
 
-			IfcVector2 last_proj; 
-			//const IfcVector2& first_proj; 
-
 			const Contour::const_iterator cbegin = (*it).contour.begin(), cend = (*it).contour.end();
 
 			bool drop_this_edge = false;
@@ -923,18 +928,8 @@ size_t CloseWindows(ContourVector& contours,
 				IfcFloat best = static_cast<IfcFloat>(1e10);
 				IfcVector3 bestv;
 
-				/* debug code to check for unwanted diagonal lines in window contours
-				if (cit != cbegin) {
-					const IfcVector2& vdelta = proj_point - last_proj;
-					if (std::fabs(vdelta.x-vdelta.y) < 0.5 * std::max(vdelta.x, vdelta.y)) {
-						//continue;
-					}
-				} */
-
 				const IfcVector3& world_point = minv * IfcVector3(proj_point.x,proj_point.y,0.0f);
 				
-				last_proj = proj_point;
-
 				BOOST_FOREACH(const TempOpening* opening, refs) {
 					BOOST_FOREACH(const IfcVector3& other, opening->wallPoints) {
 						const IfcFloat sqdist = (world_point - other).SquareLength();
@@ -956,8 +951,8 @@ size_t CloseWindows(ContourVector& contours,
 					curmesh.verts.pop_back();
 				}
 				else {
-					curmesh.verts.push_back(cit == cbegin ? world_point : bestv);
+					curmesh.verts.push_back(((cit == cbegin) != reverseCountourFaces) ? world_point : bestv);
-					curmesh.verts.push_back(cit == cbegin ? bestv : world_point);
+					curmesh.verts.push_back(((cit == cbegin) != reverseCountourFaces) ? bestv : world_point);
 
 					curmesh.vertcnt.push_back(4);
 					++closed;
@@ -969,8 +964,8 @@ size_t CloseWindows(ContourVector& contours,
 					continue;
 				}
 
-				curmesh.verts.push_back(world_point);
+				curmesh.verts.push_back(reverseCountourFaces ? bestv : world_point);
-				curmesh.verts.push_back(bestv);
+				curmesh.verts.push_back(reverseCountourFaces ? world_point : bestv);
 
 				if (cit == cend - 1) {
 					drop_this_edge = *skipit;
@@ -984,16 +979,11 @@ size_t CloseWindows(ContourVector& contours,
 						curmesh.verts.pop_back();
 					}
 					else {
-						curmesh.verts.push_back(start1);
+						curmesh.verts.push_back(reverseCountourFaces ? start0 : start1);
-						curmesh.verts.push_back(start0);
+						curmesh.verts.push_back(reverseCountourFaces ? start1 : start0);
 					}
 				}
 			}
-			/*
-			BOOST_FOREACH(TempOpening* opening, refs) {
-				//opening->wallPoints.clear();
-			}*/
-
 		}
 		else {
 			

code/IFCUtil.cpp

@@ -166,6 +166,23 @@ void TempMesh::RemoveDegenerates()
 	}
 }
 
+// ------------------------------------------------------------------------------------------------
+IfcVector3 TempMesh::ComputePolygonNormal(const IfcVector3* vtcs, size_t cnt, bool normalize)
+{
+	std::vector<IfcFloat> temp((cnt+2)*3);
+	for( size_t vofs = 0, i = 0; vofs < cnt; ++vofs )
+	{
+		const IfcVector3& v = vtcs[vofs];
+		temp[i++] = v.x;
+		temp[i++] = v.y;
+		temp[i++] = v.z;
+	}
+
+	IfcVector3 nor;
+	NewellNormal<3, 3, 3>(nor, cnt, &temp[0], &temp[1], &temp[2]);
+	return normalize ? nor.Normalize() : nor;
+}
+
 // ------------------------------------------------------------------------------------------------
 void TempMesh::ComputePolygonNormals(std::vector<IfcVector3>& normals, 
 	bool normalize, 
@@ -214,37 +231,148 @@ void TempMesh::ComputePolygonNormals(std::vector<IfcVector3>& normals,
 // Compute the normal of the last polygon in the given mesh
 IfcVector3 TempMesh::ComputeLastPolygonNormal(bool normalize) const
 {
-	size_t total = vertcnt.back(), vidx = verts.size() - total;
+	return ComputePolygonNormal(&verts[verts.size() - vertcnt.back()], vertcnt.back(), normalize);
-	std::vector<IfcFloat> temp((total+2)*3);
-	for(size_t vofs = 0, cnt = 0; vofs < total; ++vofs) {
-		const IfcVector3& v = verts[vidx+vofs];
-		temp[cnt++] = v.x;
-		temp[cnt++] = v.y;
-		temp[cnt++] = v.z;
-	}
-	IfcVector3 nor;
-	NewellNormal<3,3,3>(nor,total,&temp[0],&temp[1],&temp[2]);
-	return normalize ? nor.Normalize() : nor;
 }
 
+struct CompareVector
+{
+	bool operator () (const IfcVector3& a, const IfcVector3& b)
+	{
+		IfcVector3 d = a - b;
+		IfcFloat eps = 1e-6;
+		return d.x < -eps || (std::abs(d.x) < eps && d.y < -eps) || (std::abs(d.x) < eps && std::abs(d.y) < eps && d.z < -eps);
+	}
+};
+struct FindVector
+{
+	IfcVector3 v;
+	FindVector(const IfcVector3& p) : v(p) { }
+	bool operator () (const IfcVector3& p) { return FuzzyVectorCompare(1e-6)(p, v); }
+};
+
 // ------------------------------------------------------------------------------------------------
 void TempMesh::FixupFaceOrientation()
 {
 	const IfcVector3 vavg = Center();
 
-	std::vector<IfcVector3> normals;
+	// create a list of start indices for all faces to allow random access to faces
-	ComputePolygonNormals(normals);
+	std::vector<size_t> faceStartIndices(vertcnt.size());
+	for( size_t i = 0, a = 0; a < vertcnt.size(); i += vertcnt[a], ++a )
+		faceStartIndices[a] = i;
 
-	size_t c = 0, ofs = 0;
+	// list all faces on a vertex
-	BOOST_FOREACH(unsigned int cnt, vertcnt) {
+	std::map<IfcVector3, std::vector<size_t>, CompareVector> facesByVertex;
-		if (cnt>2){
+	for( size_t a = 0; a < vertcnt.size(); ++a )
-			const IfcVector3& thisvert = verts[c];
+	{
-			if (normals[ofs]*(thisvert-vavg) < 0) {
+		for( size_t b = 0; b < vertcnt[a]; ++b )
-				std::reverse(verts.begin()+c,verts.begin()+cnt+c);
+			facesByVertex[verts[faceStartIndices[a] + b]].push_back(a);
+	}
+	// determine neighbourhood for all polys
+	std::vector<size_t> neighbour(verts.size(), SIZE_MAX);
+	std::vector<size_t> tempIntersect(10);
+	for( size_t a = 0; a < vertcnt.size(); ++a )
+	{
+		for( size_t b = 0; b < vertcnt[a]; ++b )
+		{
+			size_t ib = faceStartIndices[a] + b, nib = faceStartIndices[a] + (b + 1) % vertcnt[a];
+			const std::vector<size_t>& facesOnB = facesByVertex[verts[ib]];
+			const std::vector<size_t>& facesOnNB = facesByVertex[verts[nib]];
+			// there should be exactly one or two faces which appear in both lists. Our face and the other side
+			std::vector<size_t>::iterator sectstart = tempIntersect.begin();
+			std::vector<size_t>::iterator sectend = std::set_intersection(
+				facesOnB.begin(), facesOnB.end(), facesOnNB.begin(), facesOnNB.end(), sectstart);
+
+			if( std::distance(sectstart, sectend) != 2 )
+				continue;
+			if( *sectstart == a )
+				++sectstart;
+			neighbour[ib] = *sectstart;
+		}
+	}
+
+	// now we're getting started. We take the face which is the farthest away from the center. This face is most probably
+	// facing outwards. So we reverse this face to point outwards in relation to the center. Then we adapt neighbouring 
+	// faces to have the same winding until all faces have been tested.
+	std::vector<bool> faceDone(vertcnt.size(), false);
+	while( std::count(faceDone.begin(), faceDone.end(), false) != 0 )
+	{
+		// find the farthest of the remaining faces
+		size_t farthestIndex = SIZE_MAX;
+		IfcFloat farthestDistance = -1.0;
+		for( size_t a = 0; a < vertcnt.size(); ++a )
+		{
+			if( faceDone[a] )
+				continue;
+			IfcVector3 faceCenter = std::accumulate(verts.begin() + faceStartIndices[a],
+				verts.begin() + faceStartIndices[a] + vertcnt[a], IfcVector3(0.0)) / IfcFloat(vertcnt[a]);
+			IfcFloat dst = (faceCenter - vavg).SquareLength();
+			if( dst > farthestDistance ) { farthestDistance = dst; farthestIndex = a; }
+		}
+
+		// calculate its normal and reverse the poly if its facing towards the mesh center
+		IfcVector3 farthestNormal = ComputePolygonNormal(verts.data() + faceStartIndices[farthestIndex], vertcnt[farthestIndex]);
+		IfcVector3 farthestCenter = std::accumulate(verts.begin() + faceStartIndices[farthestIndex],
+			verts.begin() + faceStartIndices[farthestIndex] + vertcnt[farthestIndex], IfcVector3(0.0))
+			/ IfcFloat(vertcnt[farthestIndex]);
+		// We accapt a bit of negative orientation without reversing. In case of doubt, prefer the orientation given in 
+		// the file.
+		if( (farthestNormal * (farthestCenter - vavg).Normalize()) < -0.4 )
+		{
+			size_t fsi = faceStartIndices[farthestIndex], fvc = vertcnt[farthestIndex];
+			std::reverse(verts.begin() + fsi, verts.begin() + fsi + fvc);
+			std::reverse(neighbour.begin() + fsi, neighbour.begin() + fsi + fvc);
+			// because of the neighbour index belonging to the edge starting with the point at the same index, we need to 
+			// cycle the neighbours through to match the edges again.
+			// Before: points A - B - C - D with edge neighbour p - q - r - s
+			// After: points D - C - B - A, reversed neighbours are s - r - q - p, but the should be
+			//                r   q   p   s
+			for( size_t a = 0; a < fvc - 1; ++a )
+				std::swap(neighbour[fsi + a], neighbour[fsi + a + 1]);
+		}
+		faceDone[farthestIndex] = true;
+		std::vector<size_t> todo;
+		todo.push_back(farthestIndex);
+
+		// go over its neighbour faces recursively and adapt their winding order to match the farthest face 
+		while( !todo.empty() )
+		{
+			size_t tdf = todo.back();
+			size_t vsi = faceStartIndices[tdf], vc = vertcnt[tdf];
+			todo.pop_back();
+
+			// check its neighbours
+			for( size_t a = 0; a < vc; ++a )
+			{
+				// ignore neighbours if we already checked them
+				size_t nbi = neighbour[vsi + a];
+				if( nbi == SIZE_MAX || faceDone[nbi] )
+					continue;
+
+				const IfcVector3& vp = verts[vsi + a];
+				size_t nbvsi = faceStartIndices[nbi], nbvc = vertcnt[nbi];
+				std::vector<IfcVector3>::iterator it = std::find_if(verts.begin() + nbvsi, verts.begin() + nbvsi + nbvc, FindVector(vp));
+				ai_assert(it != verts.begin() + nbvsi + nbvc);
+				size_t nb_vidx = std::distance(verts.begin() + nbvsi, it);
+				// two faces winded in the same direction should have a crossed edge, where one face has p0->p1 and the other
+				// has p1'->p0'. If the next point on the neighbouring face is also the next on the current face, we need 
+				// to reverse the neighbour
+				nb_vidx = (nb_vidx + 1) % nbvc;
+				size_t oursideidx = (a + 1) % vc;
+				if( FuzzyVectorCompare(1e-6)(verts[vsi + oursideidx], verts[nbvsi + nb_vidx]) )
+				{
+					std::reverse(verts.begin() + nbvsi, verts.begin() + nbvsi + nbvc);
+					std::reverse(neighbour.begin() + nbvsi, neighbour.begin() + nbvsi + nbvc);
+					for( size_t a = 0; a < nbvc - 1; ++a )
+						std::swap(neighbour[nbvsi + a], neighbour[nbvsi + a + 1]);
+				}
+
+				// either way we're done with the neighbour. Mark it as done and continue checking from there recursively
+				faceDone[nbi] = true;
+				todo.push_back(nbi);
 			}
 		}
-		c += cnt;
+
-		++ofs;
+		// no more faces reachable from this part of the surface, start over with a disjunct part and its farthest face
 	}
 }
 

code/IFCUtil.h

@@ -97,10 +97,10 @@ struct TempMesh
 	void RemoveDegenerates();
 
 	void FixupFaceOrientation();
+
+	static IfcVector3 ComputePolygonNormal(const IfcVector3* vtcs, size_t cnt, bool normalize = true);
 	IfcVector3 ComputeLastPolygonNormal(bool normalize = true) const;
-	void ComputePolygonNormals(std::vector<IfcVector3>& normals, 
+	void ComputePolygonNormals(std::vector<IfcVector3>& normals, bool normalize = true, size_t ofs = 0) const;
-		bool normalize = true, 
-		size_t ofs = 0) const;
 
 	void Swap(TempMesh& other);
 };
@@ -195,9 +195,19 @@ struct ConversionData
 	std::vector<aiMesh*> meshes;
 	std::vector<aiMaterial*> materials;
 
-	typedef std::map<const IFC::IfcRepresentationItem*, std::vector<unsigned int> > MeshCache;
+	struct MeshCacheIndex {
+		const IFC::IfcRepresentationItem* item; unsigned int matindex;
+		MeshCacheIndex() : item(NULL), matindex(0) { }
+		MeshCacheIndex(const IFC::IfcRepresentationItem* i, unsigned int mi) : item(i), matindex(mi) { }
+		bool operator == (const MeshCacheIndex& o) const { return item == o.item && matindex == o.matindex; }
+		bool operator < (const MeshCacheIndex& o) const { return item < o.item || (item == o.item && matindex < o.matindex); }
+	};
+	typedef std::map<MeshCacheIndex, std::vector<unsigned int> > MeshCache;
 	MeshCache cached_meshes;
 
+	typedef std::map<const IFC::IfcSurfaceStyle*, unsigned int> MaterialCache;
+	MaterialCache cached_materials;
+
 	const IFCImporter::Settings& settings;
 
 	// Intermediate arrays used to resolve openings in walls: only one of them
@@ -220,7 +230,7 @@ struct FuzzyVectorCompare {
 
 	FuzzyVectorCompare(IfcFloat epsilon) : epsilon(epsilon) {}
 	bool operator()(const IfcVector3& a, const IfcVector3& b) {
-		return std::fabs((a-b).SquareLength()) < epsilon;
+		return std::abs((a-b).SquareLength()) < epsilon;
 	}
 
 	const IfcFloat epsilon;
@@ -263,11 +273,11 @@ IfcFloat ConvertSIPrefix(const std::string& prefix);
 bool ProcessProfile(const IfcProfileDef& prof, TempMesh& meshout, ConversionData& conv);
 
 // IFCMaterial.cpp
-unsigned int ProcessMaterials(const IFC::IfcRepresentationItem& item, ConversionData& conv);
+unsigned int ProcessMaterials(uint64_t id, unsigned int prevMatId, ConversionData& conv, bool forceDefaultMat);
 
 // IFCGeometry.cpp
 IfcMatrix3 DerivePlaneCoordinateSpace(const TempMesh& curmesh, bool& ok, IfcVector3& norOut);
-bool ProcessRepresentationItem(const IfcRepresentationItem& item, std::vector<unsigned int>& mesh_indices, ConversionData& conv);
+bool ProcessRepresentationItem(const IfcRepresentationItem& item, unsigned int matid, std::vector<unsigned int>& mesh_indices, ConversionData& conv);
 void AssignAddedMeshes(std::vector<unsigned int>& mesh_indices,aiNode* nd,ConversionData& /*conv*/);
 
 void ProcessSweptAreaSolid(const IfcSweptAreaSolid& swept, TempMesh& meshout, 

code/ImporterRegistry.cpp

@@ -170,6 +170,10 @@ corresponding preprocessor flag to selectively disable formats.
 #   include "AssbinLoader.h"
 #endif 
 
+#ifndef ASSIMP_BUILD_NO_C4D_IMPORTER
+#   include "C4DImporter.h"
+#endif
+
 namespace Assimp {
 
 // ------------------------------------------------------------------------------------------------
@@ -297,6 +301,10 @@ void GetImporterInstanceList(std::vector< BaseImporter* >& out)
 #if ( !defined ASSIMP_BUILD_NO_ASSBIN_IMPORTER )
 	out.push_back( new AssbinImporter() );
 #endif
+
+#ifndef ASSIMP_BUILD_NO_C4D_IMPORTER
+	out.push_back( new C4DImporter() );
+#endif
 }
 
 }