- Ifc: refactor code, move opening generation and boolean clipping code to separate units.

code/CMakeLists.txt

@@ -381,6 +381,8 @@ SET(IFC_SRCS
 	IFCMaterial.cpp
 	IFCProfile.cpp
 	IFCCurve.cpp
+	IFCBoolean.cpp
+	IFCOpenings.cpp
 	STEPFile.h
 	STEPFileReader.h
 	STEPFileReader.cpp

code/IFCUtil.h

@@ -61,7 +61,9 @@ namespace IFC {
 	typedef aiColor4t<IfcFloat> IfcColor4; 
 
 
-// helper for std::for_each to delete all heap-allocated items in a container
+// ------------------------------------------------------------------------------------------------
+// Helper for std::for_each to delete all heap-allocated items in a container
+// ------------------------------------------------------------------------------------------------
 template<typename T>
 struct delete_fun
 {
@@ -70,10 +72,43 @@ struct delete_fun
 	}
 };
 
+
+
+// ------------------------------------------------------------------------------------------------
+// Helper used during mesh construction. Aids at creating aiMesh'es out of relatively few polygons.
+// ------------------------------------------------------------------------------------------------
+struct TempMesh
+{
+	std::vector<IfcVector3> verts;
+	std::vector<unsigned int> vertcnt;
+
+	// utilities
+	aiMesh* ToMesh();
+	void Clear();
+	void Transform(const IfcMatrix4& mat);
+	IfcVector3 Center() const;
+	void Append(const TempMesh& other);
+
+	bool IsEmpty() const {
+		return verts.empty() && vertcnt.empty();
+	}
+
+	void RemoveAdjacentDuplicates();
+	void RemoveDegenerates();
+
+	void FixupFaceOrientation();
+	IfcVector3 ComputeLastPolygonNormal(bool normalize = true) const;
+	void ComputePolygonNormals(std::vector<IfcVector3>& normals, 
+		bool normalize = true, 
+		size_t ofs = 0) const;
+
+	void Swap(TempMesh& other);
+};
+
+
 // ------------------------------------------------------------------------------------------------
 // Temporary representation of an opening in a wall or a floor
 // ------------------------------------------------------------------------------------------------
-struct TempMesh;
 struct TempOpening 
 {
 	const IFC::IfcSolidModel* solid;
@@ -110,6 +145,21 @@ struct TempOpening
 
 	// ------------------------------------------------------------------------------
 	void Transform(const IfcMatrix4& mat); // defined later since TempMesh is not complete yet
+
+
+
+	// ------------------------------------------------------------------------------
+	// Helper to sort openings by distance from a given base point
+	struct DistanceSorter {
+
+		DistanceSorter(const IfcVector3& base) : base(base) {}
+
+		bool operator () (const TempOpening& a, const TempOpening& b) const {
+			return (a.profileMesh->Center()-base).SquareLength() < (b.profileMesh->Center()-base).SquareLength();
+		}
+
+		IfcVector3 base;
+	};
 };
 
 
@@ -160,6 +210,7 @@ struct ConversionData
 	std::vector<TempOpening>* collect_openings;
 };
 
+
 // ------------------------------------------------------------------------------------------------
 // Binary predicate to compare vectors with a given, quadratic epsilon.
 // ------------------------------------------------------------------------------------------------
@@ -175,40 +226,21 @@ struct FuzzyVectorCompare {
 
 
 // ------------------------------------------------------------------------------------------------
-// Helper used during mesh construction. Aids at creating aiMesh'es out of relatively few polygons.
+// Ordering predicate to totally order R^2 vectors first by x and then by y
 // ------------------------------------------------------------------------------------------------
-struct TempMesh
+struct XYSorter {
-{
-	std::vector<IfcVector3> verts;
-	std::vector<unsigned int> vertcnt;
 
-	// utilities
+	// sort first by X coordinates, then by Y coordinates
-	aiMesh* ToMesh();
+	bool operator () (const IfcVector2&a, const IfcVector2& b) const {
-	void Clear();
+		if (a.x == b.x) {
-	void Transform(const IfcMatrix4& mat);
+			return a.y < b.y;
-	IfcVector3 Center() const;
+		}
-	void Append(const TempMesh& other);
+		return a.x < b.x;
-
-	bool IsEmpty() const {
-		return verts.empty() && vertcnt.empty();
 	}
-
-	void RemoveAdjacentDuplicates();
-	void RemoveDegenerates();
-
-	void FixupFaceOrientation();
-	IfcVector3 ComputeLastPolygonNormal(bool normalize = true) const;
-	void ComputePolygonNormals(std::vector<IfcVector3>& normals, 
-		bool normalize = true, 
-		size_t ofs = 0) const;
-
-	void Swap(TempMesh& other);
 };
 
 
 
-
-
 // conversion routines for common IFC entities, implemented in IFCUtil.cpp
 void ConvertColor(aiColor4D& out, const IfcColourRgb& in);
 void ConvertColor(aiColor4D& out, const IfcColourOrFactor& in,ConversionData& conv,const aiColor4D* base);
@@ -232,9 +264,40 @@ bool ProcessProfile(const IfcProfileDef& prof, TempMesh& meshout, ConversionData
 unsigned int ProcessMaterials(const IFC::IfcRepresentationItem& item, ConversionData& conv);
 
 // IFCGeometry.cpp
+IfcMatrix3 DerivePlaneCoordinateSpace(const TempMesh& curmesh, bool& ok, IfcVector3& norOut);
 bool ProcessRepresentationItem(const IfcRepresentationItem& item, 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, 
+						   ConversionData& conv);
+
+void ProcessExtrudedAreaSolid(const IfcExtrudedAreaSolid& solid, TempMesh& result, 
+							  ConversionData& conv, bool collect_openings);
+
+// IFCBoolean.cpp
+
+void ProcessBoolean(const IfcBooleanResult& boolean, TempMesh& result, ConversionData& conv);
+void ProcessBooleanHalfSpaceDifference(const IfcHalfSpaceSolid* hs, TempMesh& result, 
+									   const TempMesh& first_operand, 
+									   ConversionData& conv);
+
+void ProcessPolygonalBoundedBooleanHalfSpaceDifference(const IfcPolygonalBoundedHalfSpace* hs, TempMesh& result, 
+													   const TempMesh& first_operand, 
+													   ConversionData& conv);
+void ProcessBooleanExtrudedAreaSolidDifference(const IfcExtrudedAreaSolid* as, TempMesh& result, 
+											   const TempMesh& first_operand, 
+											   ConversionData& conv);
+
+
+// IFCOpenings.cpp
+
+bool GenerateOpenings(std::vector<TempOpening>& openings,
+					  const std::vector<IfcVector3>& nors, 
+					  TempMesh& curmesh,
+					  bool check_intersection,
+					  bool generate_connection_geometry,
+					  const IfcVector3& wall_extrusion_axis = IfcVector3(0,1,0));
+
 
 // IFCCurve.cpp
 
@@ -338,7 +401,8 @@ public:
 	using Curve::SampleDiscrete;
 };
 
-
+// IfcProfile.cpp
+bool ProcessCurve(const IfcCurve& curve,  TempMesh& meshout, ConversionData& conv);
 
 }
 }

code/IfcBoolean.cpp

@@ -0,0 +1,307 @@
+/*
+Open Asset Import Library (assimp)
+----------------------------------------------------------------------
+
+Copyright (c) 2006-2010, 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  IFCBoolean.cpp
+ *  @brief Implements a subset of Ifc boolean operations
+ */
+
+#include "AssimpPCH.h"
+
+#ifndef ASSIMP_BUILD_NO_IFC_IMPORTER
+#include "IFCUtil.h"
+#include "PolyTools.h"
+#include "ProcessHelper.h"
+
+#include <iterator>
+
+namespace Assimp {
+	namespace IFC {
+		
+// ------------------------------------------------------------------------------------------------
+enum Intersect {
+	Intersect_No,
+	Intersect_LiesOnPlane,
+	Intersect_Yes
+};
+
+// ------------------------------------------------------------------------------------------------
+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 IfcFloat dotOne = n*seg, dotTwo = -(n*pdelta);
+
+	if (fabs(dotOne) < 1e-6) {
+		return fabs(dotTwo) < 1e-6f ? Intersect_LiesOnPlane : Intersect_No;
+	}
+
+	const IfcFloat t = dotTwo/dotOne;
+	// t must be in [0..1] if the intersection point is within the given segment
+	if (t > 1.f || t < 0.f) {
+		return Intersect_No;
+	}
+	out = e0+t*seg;
+	return Intersect_Yes;
+}
+
+// ------------------------------------------------------------------------------------------------
+void ProcessBooleanHalfSpaceDifference(const IfcHalfSpaceSolid* hs, TempMesh& result, 
+									   const TempMesh& first_operand, 
+									   ConversionData& conv)
+{
+	ai_assert(hs != NULL);
+
+	const IfcPlane* const plane = hs->BaseSurface->ToPtr<IfcPlane>();
+	if(!plane) {
+		IFCImporter::LogError("expected IfcPlane as base surface for the IfcHalfSpaceSolid");
+		return;
+	}
+
+	// extract plane base position vector and normal vector
+	IfcVector3 p,n(0.f,0.f,1.f);
+	if (plane->Position->Axis) {
+		ConvertDirection(n,plane->Position->Axis.Get());
+	}
+	ConvertCartesianPoint(p,plane->Position->Location);
+
+	if(!IsTrue(hs->AgreementFlag)) {
+		n *= -1.f;
+	}
+
+	// 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>::const_iterator begin = first_operand.vertcnt.begin(), 
+		end = first_operand.vertcnt.end(), iit;
+
+	outvert.reserve(in.size());
+	result.vertcnt.reserve(first_operand.vertcnt.size());
+
+	unsigned int vidx = 0;
+	for(iit = begin; iit != end; vidx += *iit++) {
+
+		unsigned int newcount = 0;
+		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 (isect == Intersect_No || isect == Intersect_LiesOnPlane) {
+				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);
+					newcount += 2;
+				}
+				else {
+					// e0 is on the wrong side, so drop it and keep e1 instead
+					outvert.push_back(isectpos);
+					++newcount;
+				}
+			}
+		}	
+
+		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 (IfcBooleanClippingResult)");
+}
+
+// ------------------------------------------------------------------------------------------------
+void ProcessPolygonalBoundedBooleanHalfSpaceDifference(const IfcPolygonalBoundedHalfSpace* hs, TempMesh& result, 
+													   const TempMesh& first_operand, 
+													   ConversionData& conv)
+{
+	ai_assert(hs != NULL);
+
+	return; // niy
+
+	
+}
+
+// ------------------------------------------------------------------------------------------------
+void ProcessBooleanExtrudedAreaSolidDifference(const IfcExtrudedAreaSolid* as, TempMesh& result, 
+											   const TempMesh& first_operand, 
+											   ConversionData& conv)
+{
+	ai_assert(as != NULL);
+
+	// This case is handled by reduction to an instance of the quadrify() algorithm.
+	// Obviously, this won't work for arbitrarily complex cases. In fact, the first
+	// operand should be near-planar. Luckily, this is usually the case in Ifc 
+	// buildings.
+
+	boost::shared_ptr<TempMesh> meshtmp(new TempMesh());
+	ProcessExtrudedAreaSolid(*as,*meshtmp,conv,false);
+
+	std::vector<TempOpening> openings(1, TempOpening(as,IfcVector3(0,0,0),meshtmp,boost::shared_ptr<TempMesh>(NULL)));
+
+	result = first_operand;
+
+	TempMesh temp;
+
+	std::vector<IfcVector3>::const_iterator vit = first_operand.verts.begin();
+	BOOST_FOREACH(unsigned int pcount, first_operand.vertcnt) {
+		temp.Clear();
+
+		temp.verts.insert(temp.verts.end(), vit, vit + pcount);
+		temp.vertcnt.push_back(pcount);
+
+		// The algorithms used to generate mesh geometry sometimes
+		// spit out lines or other degenerates which must be
+		// filtered to avoid running into assertions later on.
+
+		// ComputePolygonNormal returns the Newell normal, so the
+		// length of the normal is the area of the polygon.
+		const IfcVector3& normal = temp.ComputeLastPolygonNormal(false);
+		if (normal.SquareLength() < static_cast<IfcFloat>(1e-5)) {
+			IFCImporter::LogWarn("skipping degenerate polygon (ProcessBooleanExtrudedAreaSolidDifference)");
+			continue;
+		}
+
+		GenerateOpenings(openings, std::vector<IfcVector3>(1,IfcVector3(1,0,0)), temp, false, true);
+		result.Append(temp);
+
+		vit += pcount;
+	}
+
+	IFCImporter::LogDebug("generating CSG geometry by geometric difference to a solid (IfcExtrudedAreaSolid)");
+}
+
+// ------------------------------------------------------------------------------------------------
+void ProcessBoolean(const IfcBooleanResult& boolean, TempMesh& result, ConversionData& conv)
+{
+	// supported CSG operations:
+	//   DIFFERENCE
+	if(const IfcBooleanResult* const clip = boolean.ToPtr<IfcBooleanResult>()) {
+		if(clip->Operator != "DIFFERENCE") {
+			IFCImporter::LogWarn("encountered unsupported boolean operator: " + (std::string)clip->Operator);
+			return;
+		}
+
+		// supported cases (1st operand):
+		//  IfcBooleanResult -- call ProcessBoolean recursively
+		//  IfcSweptAreaSolid -- obtain polygonal geometry first
+
+		// supported cases (2nd operand):
+		//  IfcHalfSpaceSolid -- easy, clip against plane
+		//  IfcExtrudedAreaSolid -- reduce to an instance of the quadrify() algorithm
+
+
+		const IfcHalfSpaceSolid* const hs = clip->SecondOperand->ResolveSelectPtr<IfcHalfSpaceSolid>(conv.db);
+		const IfcExtrudedAreaSolid* const as = clip->SecondOperand->ResolveSelectPtr<IfcExtrudedAreaSolid>(conv.db);
+		if(!hs && !as) {
+			IFCImporter::LogError("expected IfcHalfSpaceSolid or IfcExtrudedAreaSolid as second clipping operand");
+			return;
+		}
+
+		TempMesh first_operand;
+		if(const IfcBooleanResult* const op0 = clip->FirstOperand->ResolveSelectPtr<IfcBooleanResult>(conv.db)) {
+			ProcessBoolean(*op0,first_operand,conv);
+		}
+		else if (const IfcSweptAreaSolid* const swept = clip->FirstOperand->ResolveSelectPtr<IfcSweptAreaSolid>(conv.db)) {
+			ProcessSweptAreaSolid(*swept,first_operand,conv);
+		}
+		else {
+			IFCImporter::LogError("expected IfcSweptAreaSolid or IfcBooleanResult as first clipping operand");
+			return;
+		}
+
+		if(hs) {
+			const IfcPolygonalBoundedHalfSpace* const hs_bounded = clip->SecondOperand->ResolveSelectPtr<IfcPolygonalBoundedHalfSpace>(conv.db);
+			if (hs_bounded) {
+				ProcessPolygonalBoundedBooleanHalfSpaceDifference(hs_bounded, result, first_operand, conv);
+			}
+			else {
+				ProcessBooleanHalfSpaceDifference(hs, result, first_operand, conv);
+			}
+		}
+		else {
+			ProcessBooleanExtrudedAreaSolidDifference(as, result, first_operand, conv);
+		}
+	}
+	else {
+		IFCImporter::LogWarn("skipping unknown IfcBooleanResult entity, type is " + boolean.GetClassName());
+	}
+}
+
+} // ! IFC
+} // ! Assimp
+
+#endif 
+

workspaces/vc9/assimp.vcproj

@@ -1967,6 +1967,10 @@
 				<Filter
 					Name="ifc"
 					>
+					<File
+						RelativePath="..\..\code\IfcBoolean.cpp"
+						>
+					</File>
 					<File
 						RelativePath="..\..\code\IFCCurve.cpp"
 						>
@@ -1987,6 +1991,10 @@
 						RelativePath="..\..\code\IFCMaterial.cpp"
 						>
 					</File>
+					<File
+						RelativePath="..\..\code\IFCOpenings.cpp"
+						>
+					</File>
 					<File
 						RelativePath="..\..\code\IFCProfile.cpp"
 						>