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ViewCellBsp.cpp @ 611

Revision 611, 75.8 KB checked in by mattausch, 19 years ago (diff)

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1	#include "Plane3.h"
2	#include "ViewCellBsp.h"
3	#include "Mesh.h"
4	#include "common.h"
5	#include "ViewCell.h"
6	#include "Environment.h"
7	#include "Polygon3.h"
8	#include "Ray.h"
9	#include "AxisAlignedBox3.h"
10	#include "Triangle3.h"
11	#include "Tetrahedron3.h"
12	#include "ViewCellsManager.h"
13	#include "Exporter.h"
14	#include "Plane3.h"
15	#include <stack>
16
17
18
19	//-- static members
20
21	int BspNode::sMailId = 1;
22
23	/** Evaluates split plane classification with respect to the plane's
24	contribution for a minimum number splits in the tree.
25	*/
26	const float BspTree::sLeastPolySplitsTable[] = {0, 0, 1, 0};
27	/** Evaluates split plane classification with respect to the plane's
28	contribution for a balanced tree.
29	*/
30	const float BspTree::sBalancedPolysTable[] = {1, -1, 0, 0};
31
32	/** Evaluates split plane classification with respect to the plane's
33	contribution for a minimum number of ray splits.
34	*/
35	const float BspTree::sLeastRaySplitsTable[] = {0, 0, 1, 1, 0};
36	/** Evaluates split plane classification with respect to the plane's
37	contribution for balanced rays.
38	*/
39	const float BspTree::sBalancedRaysTable[] = {1, -1, 0, 0, 0};
40
41	int BspTree::sFrontId = 0;
42	int BspTree::sBackId = 0;
43	int BspTree::sFrontAndBackId = 0;
44
45
46	/****************************************************************/
47	/* class BspNode implementation */
48	/****************************************************************/
49
50
51	BspNode::BspNode():
52	mParent(NULL), mTreeValid(true), mTimeStamp(0)
53	{}
54
55	BspNode::BspNode(BspInterior *parent):
56	mParent(parent), mTreeValid(true)
57	{}
58
59
60	bool BspNode::IsRoot() const
61	{
62	return mParent == NULL;
63	}
64
65
66	BspInterior *BspNode::GetParent()
67	{
68	return mParent;
69	}
70
71
72	void BspNode::SetParent(BspInterior *parent)
73	{
74	mParent = parent;
75	}
76
77
78	bool BspNode::IsSibling(BspNode *n) const
79	{
80	return ((this != n) && mParent &&
81	(mParent->GetFront() == n) \|\| (mParent->GetBack() == n));
82	}
83
84
85	int BspNode::GetDepth() const
86	{
87	int depth = 0;
88	BspNode *p = mParent;
89
90	while (p)
91	{
92	p = p->mParent;
93	++ depth;
94	}
95
96	return depth;
97	}
98
99
100	bool BspNode::TreeValid() const
101	{
102	return mTreeValid;
103	}
104
105
106	void BspNode::SetTreeValid(const bool v)
107	{
108	mTreeValid = v;
109	}
110
111
112	/****************************************************************/
113	/* class BspInterior implementation */
114	/****************************************************************/
115
116
117	BspInterior::BspInterior(const Plane3 &plane):
118	mPlane(plane), mFront(NULL), mBack(NULL)
119	{}
120
121	BspInterior::~BspInterior()
122	{
123	DEL_PTR(mFront);
124	DEL_PTR(mBack);
125	}
126
127	bool BspInterior::IsLeaf() const
128	{
129	return false;
130	}
131
132	BspNode *BspInterior::GetBack()
133	{
134	return mBack;
135	}
136
137	BspNode *BspInterior::GetFront()
138	{
139	return mFront;
140	}
141
142	Plane3 BspInterior::GetPlane() const
143	{
144	return mPlane;
145	}
146
147	void BspInterior::ReplaceChildLink(BspNode oldChild, BspNode newChild)
148	{
149	if (mBack == oldChild)
150	mBack = newChild;
151	else
152	mFront = newChild;
153	}
154
155	void BspInterior::SetupChildLinks(BspNode b, BspNode f)
156	{
157	mBack = b;
158	mFront = f;
159	}
160
161	/****************************************************************/
162	/* class BspLeaf implementation */
163	/****************************************************************/
164
165
166	BspLeaf::BspLeaf(): mViewCell(NULL), mPvs(NULL)
167	{
168	}
169
170
171	BspLeaf::~BspLeaf()
172	{
173	DEL_PTR(mPvs);
174	}
175
176
177	BspLeaf::BspLeaf(ViewCell *viewCell):
178	mViewCell(viewCell)
179	{
180	}
181
182
183	BspLeaf::BspLeaf(BspInterior *parent):
184	BspNode(parent), mViewCell(NULL), mPvs(NULL)
185	{}
186
187
188
189	BspLeaf::BspLeaf(BspInterior parent, ViewCell viewCell):
190	BspNode(parent), mViewCell(viewCell), mPvs(NULL)
191	{
192	}
193
194	ViewCell *BspLeaf::GetViewCell() const
195	{
196	return mViewCell;
197	}
198
199	void BspLeaf::SetViewCell(ViewCell *viewCell)
200	{
201	mViewCell = viewCell;
202	}
203
204
205	bool BspLeaf::IsLeaf() const
206	{
207	return true;
208	}
209
210
211	/*********************************************************************/
212	/* class BspTree implementation */
213	/*********************************************************************/
214
215	BspTree::BspTree():
216	mRoot(NULL),
217	mUseAreaForPvs(false),
218	mGenerateViewCells(true),
219	mTimeStamp(0)
220	{
221	Randomize(); // initialise random generator for heuristics
222
223	mOutOfBoundsCell = GetOrCreateOutOfBoundsCell();
224
225	//-- termination criteria for autopartition
226	environment->GetIntValue("BspTree.Termination.maxDepth", mTermMaxDepth);
227	environment->GetIntValue("BspTree.Termination.minPvs", mTermMinPvs);
228	environment->GetIntValue("BspTree.Termination.minPolygons", mTermMinPolys);
229	environment->GetIntValue("BspTree.Termination.minRays", mTermMinRays);
230	environment->GetFloatValue("BspTree.Termination.minProbability", mTermMinProbability);
231	environment->GetFloatValue("BspTree.Termination.maxRayContribution", mTermMaxRayContribution);
232	environment->GetFloatValue("BspTree.Termination.minAccRayLenght", mTermMinAccRayLength);
233
234	//-- factors for bsp tree split plane heuristics
235	environment->GetFloatValue("BspTree.Factor.verticalSplits", mVerticalSplitsFactor);
236	environment->GetFloatValue("BspTree.Factor.largestPolyArea", mLargestPolyAreaFactor);
237	environment->GetFloatValue("BspTree.Factor.blockedRays", mBlockedRaysFactor);
238	environment->GetFloatValue("BspTree.Factor.leastRaySplits", mLeastRaySplitsFactor);
239	environment->GetFloatValue("BspTree.Factor.balancedRays", mBalancedRaysFactor);
240	environment->GetFloatValue("BspTree.Factor.pvs", mPvsFactor);
241	environment->GetFloatValue("BspTree.Factor.leastSplits" , mLeastSplitsFactor);
242	environment->GetFloatValue("BspTree.Factor.balancedPolys", mBalancedPolysFactor);
243	environment->GetFloatValue("BspTree.Factor.balancedViewCells", mBalancedViewCellsFactor);
244	environment->GetFloatValue("BspTree.Termination.ct_div_ci", mCtDivCi);
245
246	//-- termination criteria for axis aligned split
247	environment->GetFloatValue("BspTree.Termination.AxisAligned.ct_div_ci", mAxisAlignedCtDivCi);
248	environment->GetFloatValue("BspTree.Termination.maxCostRatio", mMaxCostRatio);
249	environment->GetIntValue("BspTree.Termination.AxisAligned.minPolys",
250	mTermMinPolysForAxisAligned);
251	environment->GetIntValue("BspTree.Termination.AxisAligned.minRays",
252	mTermMinRaysForAxisAligned);
253	environment->GetIntValue("BspTree.Termination.AxisAligned.minObjects",
254	mTermMinObjectsForAxisAligned);
255	//-- partition criteria
256	environment->GetIntValue("BspTree.maxPolyCandidates", mMaxPolyCandidates);
257	environment->GetIntValue("BspTree.maxRayCandidates", mMaxRayCandidates);
258	environment->GetIntValue("BspTree.splitPlaneStrategy", mSplitPlaneStrategy);
259	environment->GetFloatValue("BspTree.AxisAligned.splitBorder", mSplitBorder);
260	environment->GetIntValue("BspTree.maxTests", mMaxTests);
261	environment->GetIntValue("BspTree.Termination.maxViewCells", mMaxViewCells);
262
263	environment->GetFloatValue("BspTree.Construction.epsilon", mEpsilon);
264
265	mSubdivisionStats.open("subdivisionStats.log");
266
267	Debug << "BSP max depth: " << mTermMaxDepth << endl;
268	Debug << "BSP min PVS: " << mTermMinPvs << endl;
269	Debug << "BSP min probability: " << mTermMinProbability << endl;
270	Debug << "BSP max polys: " << mTermMinPolys << endl;
271	Debug << "BSP max rays: " << mTermMinRays << endl;
272	Debug << "BSP max polygon candidates: " << mMaxPolyCandidates << endl;
273	Debug << "BSP max plane candidates: " << mMaxRayCandidates << endl;
274
275	Debug << "Split plane strategy: ";
276	if (mSplitPlaneStrategy & RANDOM_POLYGON)
277	Debug << "random polygon ";
278	if (mSplitPlaneStrategy & AXIS_ALIGNED)
279	Debug << "axis aligned ";
280	if (mSplitPlaneStrategy & LEAST_SPLITS)
281	Debug << "least splits ";
282	if (mSplitPlaneStrategy & BALANCED_POLYS)
283	Debug << "balanced polygons ";
284	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
285	Debug << "balanced view cells ";
286	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
287	Debug << "largest polygon area ";
288	if (mSplitPlaneStrategy & VERTICAL_AXIS)
289	Debug << "vertical axis ";
290	if (mSplitPlaneStrategy & BLOCKED_RAYS)
291	Debug << "blocked rays ";
292	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
293	Debug << "least ray splits ";
294	if (mSplitPlaneStrategy & BALANCED_RAYS)
295	Debug << "balanced rays ";
296	if (mSplitPlaneStrategy & PVS)
297	Debug << "pvs";
298
299	Debug << endl;
300	}
301
302
303	const BspTreeStatistics &BspTree::GetStatistics() const
304	{
305	return mStat;
306	}
307
308
309	int BspTree::SplitPolygons(const Plane3 &plane,
310	PolygonContainer &polys,
311	PolygonContainer &frontPolys,
312	PolygonContainer &backPolys,
313	PolygonContainer &coincident) const
314	{
315	int splits = 0;
316
317	#ifdef _Debug
318	Debug << "splitting polygons of node " << this << " with plane " << mPlane << endl;
319	#endif
320	PolygonContainer::const_iterator it, it_end = polys.end();
321
322	for (it = polys.begin(); it != polys.end(); ++ it)
323	{
324	Polygon3 poly = it;
325
326	//-- classify polygon
327	const int cf = poly->ClassifyPlane(plane, mEpsilon);
328
329	switch (cf)
330	{
331	case Polygon3::COINCIDENT:
332	coincident.push_back(poly);
333	break;
334	case Polygon3::FRONT_SIDE:
335	frontPolys.push_back(poly);
336	break;
337	case Polygon3::BACK_SIDE:
338	backPolys.push_back(poly);
339	break;
340	case Polygon3::SPLIT:
341	{
342	Polygon3 *front_piece = new Polygon3(poly->mParent);
343	Polygon3 *back_piece = new Polygon3(poly->mParent);
344
345	//-- split polygon into front and back part
346	poly->Split(plane,
347	*front_piece,
348	*back_piece,
349	mEpsilon);
350
351	++ splits; // increase number of splits
352
353	//-- inherit rays from parent polygon for blocked ray criterium
354	poly->InheritRays(front_piece, back_piece);
355
356	// check if polygons still valid
357	if (front_piece->Valid(mEpsilon))
358	frontPolys.push_back(front_piece);
359	else
360	DEL_PTR(front_piece);
361
362	if (back_piece->Valid(mEpsilon))
363	backPolys.push_back(back_piece);
364	else
365	DEL_PTR(back_piece);
366
367	#ifdef _DEBUG
368	Debug << "split " << poly << endl << front_piece << endl << *back_piece << endl;
369	#endif
370	DEL_PTR(poly);
371	}
372	break;
373	default:
374	Debug << "SHOULD NEVER COME HERE\n";
375	break;
376	}
377	}
378
379	return splits;
380	}
381
382
383	void BspTreeStatistics::Print(ostream &app) const
384	{
385	app << "===== BspTree statistics ===============\n";
386
387	app << setprecision(4);
388
389	app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
390
391	app << "#N_NODES ( Number of nodes )\n" << nodes << "\n";
392
393	app << "#N_INTERIORS ( Number of interior nodes )\n" << Interior() << "\n";
394
395	app << "#N_LEAVES ( Number of leaves )\n" << Leaves() << "\n";
396
397	app << "#N_POLYSPLITS ( Number of polygon splits )\n" << polySplits << "\n";
398
399	app << "#AXIS_ALIGNED_SPLITS (number of axis aligned splits)\n" << splits[0] + splits[1] + splits[2] << endl;
400
401	app << "#N_SPLITS ( Number of splits in axes x y z\n";
402
403	for (int i = 0; i < 3; ++ i)
404	app << splits[i] << " ";
405	app << endl;
406
407	app << "#N_PMAXDEPTHLEAVES ( Percentage of leaves at maximum depth )\n"
408	<< maxDepthNodes * 100 / (double)Leaves() << endl;
409
410	app << "#N_PMINPVSLEAVES ( Percentage of leaves with mininimal PVS )\n"
411	<< minPvsNodes * 100 / (double)Leaves() << endl;
412
413	app << "#N_PMINRAYSLEAVES ( Percentage of leaves with minimal number of rays)\n"
414	<< minRaysNodes * 100 / (double)Leaves() << endl;
415
416	app << "#N_MAXCOSTNODES ( Percentage of leaves with terminated because of max cost ratio )\n"
417	<< maxCostNodes * 100 / (double)Leaves() << endl;
418
419	app << "#N_PMINPROBABILITYLEAVES ( Percentage of leaves with mininum probability )\n"
420	<< minProbabilityNodes * 100 / (double)Leaves() << endl;
421
422	app << "#N_PMAXRAYCONTRIBLEAVES ( Percentage of leaves with maximal ray contribution )\n"
423	<< maxRayContribNodes * 100 / (double)Leaves() << endl;
424
425	app << "#N_PMAXDEPTH ( Maximal reached depth )\n" << maxDepth << endl;
426
427	app << "#N_PMINDEPTH ( Minimal reached depth )\n" << minDepth << endl;
428
429	app << "#AVGDEPTH ( average depth )\n" << AvgDepth() << endl;
430
431	app << "#N_INPUTPOLYGONS (number of input polygons )\n" << polys << endl;
432
433	app << "#N_INVALIDLEAVES (number of invalid leaves )\n" << invalidLeaves << endl;
434
435	app << "#N_RAYS (number of rays / leaf)\n" << AvgRays() << endl;
436	//app << "#N_PVS: " << pvs << endl;
437
438	app << "#N_ROUTPUT_INPUT_POLYGONS ( ratio polygons after subdivision / input polygons )\n" <<
439	(polys + polySplits) / (double)polys << endl;
440
441	app << "===== END OF BspTree statistics ==========\n";
442	}
443
444
445	BspTree::~BspTree()
446	{
447	DEL_PTR(mRoot);
448
449	// TODO must be deleted if used!!
450	//if (mGenerateViewCells) DEL_PTR(mOutOfBoundsCell);
451	}
452
453	BspViewCell *BspTree::GetOutOfBoundsCell()
454	{
455	return mOutOfBoundsCell;
456	}
457
458
459	BspNode *BspTree::GetRoot() const
460	{
461	return mRoot;
462	}
463
464	BspViewCell *BspTree::GetOrCreateOutOfBoundsCell()
465	{
466	if (!mOutOfBoundsCell)
467	{
468	mOutOfBoundsCell = new BspViewCell();
469	mOutOfBoundsCell->SetId(-1);
470	mOutOfBoundsCell->SetValid(false);
471	}
472
473	return mOutOfBoundsCell;
474	}
475
476
477	void BspTree::InsertViewCell(ViewCell *viewCell)
478	{
479	PolygonContainer *polys = new PolygonContainer();
480
481	// don't generate new view cell, insert this one
482	mGenerateViewCells = false;
483	// extract polygons that guide the split process
484	mStat.polys += AddMeshToPolygons(viewCell->GetMesh(), *polys, viewCell);
485	mBox.Include(viewCell->GetBox()); // add to BSP aabb
486
487	InsertPolygons(polys);
488	}
489
490
491	void BspTree::InsertPolygons(PolygonContainer *polys)
492	{
493	BspTraversalStack tStack;
494
495	// traverse existing tree or create new tree
496	if (!mRoot)
497	mRoot = new BspLeaf();
498
499	tStack.push(BspTraversalData(mRoot,
500	polys,
501	0,
502	mOutOfBoundsCell,
503	new BoundedRayContainer(),
504	0,
505	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
506	new BspNodeGeometry()));
507
508	while (!tStack.empty())
509	{
510	// filter polygons donw the tree
511	BspTraversalData tData = tStack.top();
512	tStack.pop();
513
514	if (!tData.mNode->IsLeaf())
515	{
516	BspInterior interior = dynamic_cast<BspInterior >(tData.mNode);
517
518	//-- filter view cell polygons down the tree until a leaf is reached
519	if (!tData.mPolygons->empty())
520	{
521	PolygonContainer *frontPolys = new PolygonContainer();
522	PolygonContainer *backPolys = new PolygonContainer();
523	PolygonContainer coincident;
524
525	int splits = 0;
526
527	// split viewcell polygons with respect to split plane
528	splits += SplitPolygons(interior->GetPlane(),
529	*tData.mPolygons,
530	*frontPolys,
531	*backPolys,
532	coincident);
533
534	// extract view cells associated with the split polygons
535	ViewCell *frontViewCell = GetOrCreateOutOfBoundsCell();
536	ViewCell *backViewCell = GetOrCreateOutOfBoundsCell();
537
538	BspTraversalData frontData(interior->GetFront(),
539	frontPolys,
540	tData.mDepth + 1,
541	mOutOfBoundsCell,
542	tData.mRays,
543	tData.mPvs,
544	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
545	new BspNodeGeometry());
546
547	BspTraversalData backData(interior->GetBack(),
548	backPolys,
549	tData.mDepth + 1,
550	mOutOfBoundsCell,
551	tData.mRays,
552	tData.mPvs,
553	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
554	new BspNodeGeometry());
555
556	if (!mGenerateViewCells)
557	{
558	ExtractViewCells(frontData,
559	backData,
560	coincident,
561	interior->mPlane);
562	}
563
564	// don't need coincident polygons anymore
565	CLEAR_CONTAINER(coincident);
566
567	mStat.polySplits += splits;
568
569	// push the children on the stack
570	tStack.push(frontData);
571	tStack.push(backData);
572	}
573
574	// cleanup
575	DEL_PTR(tData.mPolygons);
576	DEL_PTR(tData.mRays);
577	}
578	else
579	{
580	// reached leaf => subdivide current viewcell
581	BspNode *subRoot = Subdivide(tStack, tData);
582	}
583	}
584	}
585
586	int BspTree::AddMeshToPolygons(Mesh *mesh,
587	PolygonContainer &polys,
588	MeshInstance *parent)
589	{
590	FaceContainer::const_iterator fi;
591
592	// copy the face data to polygons
593	for (fi = mesh->mFaces.begin(); fi != mesh->mFaces.end(); ++ fi)
594	{
595	Polygon3 poly = new Polygon3((fi), mesh);
596
597	if (poly->Valid(mEpsilon))
598	{
599	poly->mParent = parent; // set parent intersectable
600	polys.push_back(poly);
601	}
602	else
603	DEL_PTR(poly);
604	}
605	return (int)mesh->mFaces.size();
606	}
607
608
609	int BspTree::AddToPolygonSoup(const ViewCellContainer &viewCells,
610	PolygonContainer &polys,
611	int maxObjects)
612	{
613	int limit = (maxObjects > 0) ?
614	Min((int)viewCells.size(), maxObjects) : (int)viewCells.size();
615
616	int polysSize = 0;
617
618	for (int i = 0; i < limit; ++ i)
619	{
620	if (viewCells[i]->GetMesh()) // copy the mesh data to polygons
621	{
622	mBox.Include(viewCells[i]->GetBox()); // add to BSP tree aabb
623	polysSize += AddMeshToPolygons(viewCells[i]->GetMesh(), polys, viewCells[i]);
624	}
625	}
626
627	return polysSize;
628	}
629
630
631	int BspTree::AddToPolygonSoup(const ObjectContainer &objects,
632	PolygonContainer &polys,
633	int maxObjects,
634	bool addToBbox)
635	{
636	int limit = (maxObjects > 0) ?
637	Min((int)objects.size(), maxObjects) : (int)objects.size();
638
639	for (int i = 0; i < limit; ++i)
640	{
641	Intersectable object = objects[i];//it;
642	Mesh *mesh = NULL;
643
644	switch (object->Type()) // extract the meshes
645	{
646	case Intersectable::MESH_INSTANCE:
647	mesh = dynamic_cast<MeshInstance *>(object)->GetMesh();
648	break;
649	case Intersectable::VIEW_CELL:
650	mesh = dynamic_cast<ViewCell *>(object)->GetMesh();
651	break;
652	// TODO: handle transformed mesh instances
653	default:
654	Debug << "intersectable type not supported" << endl;
655	break;
656	}
657
658	if (mesh) // copy the mesh data to polygons
659	{
660	if (addToBbox)
661	{
662	mBox.Include(object->GetBox()); // add to BSP tree aabb
663	}
664
665	AddMeshToPolygons(mesh, polys, mOutOfBoundsCell);
666	}
667	}
668
669	return (int)polys.size();
670	}
671
672
673	void BspTree::Construct(const ViewCellContainer &viewCells)
674	{
675	mStat.nodes = 1;
676	mBox.Initialize(); // initialise bsp tree bounding box
677
678	// copy view cell meshes into one big polygon soup
679	PolygonContainer *polys = new PolygonContainer();
680	mStat.polys = AddToPolygonSoup(viewCells, *polys);
681
682	// view cells are given
683	mGenerateViewCells = false;
684	// construct tree from the view cell polygons
685	Construct(polys, new BoundedRayContainer());
686	}
687
688
689	void BspTree::Construct(const ObjectContainer &objects)
690	{
691	mStat.nodes = 1;
692	mBox.Initialize(); // initialise bsp tree bounding box
693
694	PolygonContainer *polys = new PolygonContainer();
695
696	mGenerateViewCells = true;
697	// copy mesh instance polygons into one big polygon soup
698	mStat.polys = AddToPolygonSoup(objects, *polys);
699
700	// construct tree from polygon soup
701	Construct(polys, new BoundedRayContainer());
702	}
703
704
705	void BspTree::Construct(const RayContainer &sampleRays,
706	AxisAlignedBox3 *forcedBoundingBox)
707	{
708	mStat.nodes = 1;
709	mBox.Initialize(); // initialise BSP tree bounding box
710
711	if (forcedBoundingBox)
712	mBox = *forcedBoundingBox;
713
714	PolygonContainer *polys = new PolygonContainer();
715	BoundedRayContainer *rays = new BoundedRayContainer();
716
717	RayContainer::const_iterator rit, rit_end = sampleRays.end();
718
719	// generate view cells
720	mGenerateViewCells = true;
721
722	long startTime = GetTime();
723
724	Debug << "** Extracting polygons from rays **\n";
725
726	std::map<Face , Polygon3 > facePolyMap;
727
728	//-- extract polygons intersected by the rays
729	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
730	{
731	Ray ray = rit;
732
733	// get ray-face intersection. Store polygon representing the rays together
734	// with rays intersecting the face.
735	if (!ray->intersections.empty())
736	{
737	MeshInstance obj = dynamic_cast<MeshInstance >(ray->intersections[0].mObject);
738	Face *face = obj->GetMesh()->mFaces[ray->intersections[0].mFace];
739
740	std::map<Face , Polygon3 >::iterator it = facePolyMap.find(face);
741
742	if (it != facePolyMap.end())
743	{
744	//store rays if needed for heuristics
745	if (mSplitPlaneStrategy & BLOCKED_RAYS)
746	(*it).second->mPiercingRays.push_back(ray);
747	}
748	else
749	{ //store rays if needed for heuristics
750	Polygon3 *poly = new Polygon3(face, obj->GetMesh());
751	poly->mParent = obj;
752	polys->push_back(poly);
753
754	if (mSplitPlaneStrategy & BLOCKED_RAYS)
755	poly->mPiercingRays.push_back(ray);
756
757	facePolyMap[face] = poly;
758	}
759	}
760	}
761
762	facePolyMap.clear();
763
764	// compute bounding box
765	if (!forcedBoundingBox)
766	Polygon3::IncludeInBox(*polys, mBox);
767
768	//-- store rays
769	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
770	{
771	Ray ray = rit;
772	ray->SetId(-1); // reset id
773
774	float minT, maxT;
775	if (mBox.GetRaySegment(*ray, minT, maxT))
776	rays->push_back(new BoundedRay(ray, minT, maxT));
777	}
778
779	mStat.polys = (int)polys->size();
780
781	Debug << "** Finished polygon extraction **" << endl;
782	Debug << (int)polys->size() << " polys extracted from " << (int)sampleRays.size() << " rays" << endl;
783	Debug << "extraction time: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
784
785	Construct(polys, rays);
786	}
787
788
789	void BspTree::Construct(const ObjectContainer &objects,
790	const RayContainer &sampleRays,
791	AxisAlignedBox3 *forcedBoundingBox)
792	{
793	mStat.nodes = 1;
794	mBox.Initialize(); // initialise BSP tree bounding box
795
796	if (forcedBoundingBox)
797	mBox = *forcedBoundingBox;
798
799	BoundedRayContainer *rays = new BoundedRayContainer();
800	PolygonContainer *polys = new PolygonContainer();
801
802	mGenerateViewCells = true;
803
804	// copy mesh instance polygons into one big polygon soup
805	mStat.polys = AddToPolygonSoup(objects, *polys, 0, !forcedBoundingBox);
806
807
808	RayContainer::const_iterator rit, rit_end = sampleRays.end();
809
810	//-- store rays
811	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
812	{
813	Ray ray = rit;
814	ray->SetId(-1); // reset id
815
816	float minT, maxT;
817	if (mBox.GetRaySegment(*ray, minT, maxT))
818	rays->push_back(new BoundedRay(ray, minT, maxT));
819	}
820
821	Debug << "tree has " << (int)polys->size() << " polys, " << (int)sampleRays.size() << " rays" << endl;
822	Construct(polys, rays);
823	}
824
825
826	void BspTree::Construct(PolygonContainer polys, BoundedRayContainer rays)
827	{
828	BspTraversalStack tStack;
829
830	mRoot = new BspLeaf();
831
832	// constrruct root node geometry
833	BspNodeGeometry *geom = new BspNodeGeometry();
834	ConstructGeometry(mRoot, *geom);
835
836	BspTraversalData tData(mRoot,
837	polys,
838	0,
839	GetOrCreateOutOfBoundsCell(),
840	rays,
841	ComputePvsSize(*rays),
842	mUseAreaForPvs ? geom->GetArea() : geom->GetVolume(),
843	geom);
844
845	mTotalCost = tData.mPvs * tData.mProbability / mBox.GetVolume();
846	mTotalPvsSize = tData.mPvs;
847
848	mSubdivisionStats
849	<< "#ViewCells\n1\n" << endl
850	<< "#RenderCostDecrease\n0\n" << endl
851	<< "#TotalRenderCost\n" << mTotalCost << endl
852	<< "#AvgRenderCost\n" << mTotalPvsSize << endl;
853
854	tStack.push(tData);
855
856	// used for intermediate time measurements and progress
857	long interTime = GetTime();
858	int nleaves = 500;
859
860	mStat.Start();
861	cout << "Contructing bsp tree ...\n";
862	long startTime = GetTime();
863	while (!tStack.empty())
864	{
865	tData = tStack.top();
866
867	tStack.pop();
868
869	// subdivide leaf node
870	BspNode *r = Subdivide(tStack, tData);
871
872	if (r == mRoot)
873	Debug << "BSP tree construction time spent at root: "
874	<< TimeDiff(startTime, GetTime())*1e-3 << " secs" << endl;
875
876	if (mStat.Leaves() >= nleaves)
877	{
878	nleaves += 500;
879
880	cout << "leaves=" << mStat.Leaves() << endl;
881	Debug << "needed "
882	<< TimeDiff(interTime, GetTime())*1e-3
883	<< " secs to create 500 leaves" << endl;
884	interTime = GetTime();
885	}
886	}
887
888	cout << "finished\n";
889
890	mStat.Stop();
891	}
892
893
894	bool BspTree::TerminationCriteriaMet(const BspTraversalData &data) const
895	{
896	return
897	(((int)data.mPolygons->size() <= mTermMinPolys) \|\|
898	((int)data.mRays->size() <= mTermMinRays) \|\|
899	(data.mPvs <= mTermMinPvs) \|\|
900	(data.mProbability <= mTermMinProbability) \|\|
901	(data.mDepth >= mTermMaxDepth) \|\|
902	(mStat.Leaves() >= mMaxViewCells) \|\|
903	(data.GetAvgRayContribution() > mTermMaxRayContribution));
904	}
905
906
907	BspNode *BspTree::Subdivide(BspTraversalStack &tStack, BspTraversalData &tData)
908	{
909	//-- terminate traversal
910	if (TerminationCriteriaMet(tData))
911	{
912	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
913
914	BspViewCell *viewCell;
915
916	// generate new view cell for each leaf
917	if (mGenerateViewCells)
918	viewCell = new BspViewCell();
919	else
920	// add view cell to leaf
921	viewCell = dynamic_cast<BspViewCell *>(tData.mViewCell);
922
923	leaf->SetViewCell(viewCell);
924	viewCell->mLeaf = leaf;
925
926	if (mUseAreaForPvs)
927	viewCell->SetArea(tData.mProbability);
928	else
929	viewCell->SetVolume(tData.mProbability);
930
931	//-- add pvs
932	if (viewCell != mOutOfBoundsCell)
933	{
934	int conSamp = 0, sampCon = 0;
935	AddToPvs(leaf, *tData.mRays, conSamp, sampCon);
936
937	mStat.contributingSamples += conSamp;
938	mStat.sampleContributions += sampCon;
939	}
940
941	EvaluateLeafStats(tData);
942
943	//-- clean up
944
945	// discard polygons
946	CLEAR_CONTAINER(*tData.mPolygons);
947	// discard rays
948	CLEAR_CONTAINER(*tData.mRays);
949
950	DEL_PTR(tData.mPolygons);
951	DEL_PTR(tData.mRays);
952	DEL_PTR(tData.mGeometry);
953
954	return leaf;
955	}
956
957	//-- continue subdivision
958	PolygonContainer coincident;
959
960	BspTraversalData tFrontData(NULL, new PolygonContainer(), tData.mDepth + 1, mOutOfBoundsCell,
961	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
962	BspTraversalData tBackData(NULL, new PolygonContainer(), tData.mDepth + 1, mOutOfBoundsCell,
963	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
964
965	int pvsData = tData.mPvs;
966	float cData = (float)tData.mPvs * tData.mProbability;
967
968	// create new interior node and two leaf nodes
969	BspInterior *interior =
970	SubdivideNode(tData, tFrontData, tBackData, coincident);
971
972
973	if (1)
974	{
975	float cFront = (float)tFrontData.mPvs * tFrontData.mProbability;
976	float cBack = (float)tBackData.mPvs * tBackData.mProbability;
977
978	float costDecr =
979	(cFront + cBack - cData) / mBox.GetVolume();
980
981
982	mTotalCost += costDecr;
983	mTotalPvsSize += tFrontData.mPvs + tBackData.mPvs - pvsData;
984
985	mSubdivisionStats
986	<< "#ViewCells\n" << mStat.Leaves() << endl
987	<< "#RenderCostDecrease\n" << -costDecr << endl
988	<< "#TotalRenderCost\n" << mTotalCost << endl
989	<< "#AvgRenderCost\n" << mTotalPvsSize / mStat.Leaves() << endl;
990	}
991
992	// extract view cells from coincident polygons according to plane normal
993	// only if front or back polygons are empty
994	if (!mGenerateViewCells)
995	{
996	ExtractViewCells(tFrontData,
997	tBackData,
998	coincident,
999	interior->mPlane);
1000	}
1001
1002	// don't need coincident polygons anymory
1003	CLEAR_CONTAINER(coincident);
1004
1005	// push the children on the stack
1006	tStack.push(tFrontData);
1007	tStack.push(tBackData);
1008
1009	// cleanup
1010	DEL_PTR(tData.mNode);
1011
1012	DEL_PTR(tData.mPolygons);
1013	DEL_PTR(tData.mRays);
1014	DEL_PTR(tData.mGeometry);
1015
1016	return interior;
1017	}
1018
1019	void BspTree::ExtractViewCells(BspTraversalData &frontData,
1020	BspTraversalData &backData,
1021	const PolygonContainer &coincident,
1022	const Plane3 &splitPlane) const
1023	{
1024	// if not empty, tree is further subdivided => don't have to find view cell
1025	bool foundFront = !frontData.mPolygons->empty();
1026	bool foundBack = !frontData.mPolygons->empty();
1027
1028	PolygonContainer::const_iterator it =
1029	coincident.begin(), it_end = coincident.end();
1030
1031	//-- find first view cells in front and back leafs
1032	for (; !(foundFront && foundBack) && (it != it_end); ++ it)
1033	{
1034	if (DotProd((*it)->GetNormal(), splitPlane.mNormal) > 0)
1035	{
1036	backData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
1037	foundBack = true;
1038	}
1039	else
1040	{
1041	frontData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
1042	foundFront = true;
1043	}
1044	}
1045	}
1046
1047	BspInterior *BspTree::SubdivideNode(BspTraversalData &tData,
1048	BspTraversalData &frontData,
1049	BspTraversalData &backData,
1050	PolygonContainer &coincident)
1051	{
1052	mStat.nodes += 2;
1053
1054	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
1055
1056
1057
1058	// select subdivision plane
1059	BspInterior *interior =
1060	new BspInterior(SelectPlane(leaf, tData));
1061
1062
1063	#ifdef _DEBUG
1064	Debug << interior << endl;
1065	#endif
1066
1067
1068	// subdivide rays into front and back rays
1069	SplitRays(interior->mPlane, tData.mRays, frontData.mRays, *backData.mRays);
1070
1071
1072
1073	// subdivide polygons with plane
1074	mStat.polySplits += SplitPolygons(interior->GetPlane(),
1075	*tData.mPolygons,
1076	*frontData.mPolygons,
1077	*backData.mPolygons,
1078	coincident);
1079
1080
1081
1082	// compute pvs
1083	frontData.mPvs = ComputePvsSize(*frontData.mRays);
1084	backData.mPvs = ComputePvsSize(*backData.mRays);
1085
1086	// split geometry and compute area
1087	if (1)
1088	{
1089	tData.mGeometry->SplitGeometry(*frontData.mGeometry,
1090	*backData.mGeometry,
1091	interior->mPlane,
1092	mBox,
1093	mEpsilon);
1094
1095
1096	if (mUseAreaForPvs)
1097	{
1098	frontData.mProbability = frontData.mGeometry->GetArea();
1099	backData.mProbability = backData.mGeometry->GetArea();
1100	}
1101	else
1102	{
1103	frontData.mProbability = frontData.mGeometry->GetVolume();
1104	backData.mProbability = tData.mProbability - frontData.mProbability;
1105	}
1106	}
1107
1108	//-- create front and back leaf
1109
1110	BspInterior *parent = leaf->GetParent();
1111
1112	// replace a link from node's parent
1113	if (!leaf->IsRoot())
1114	{
1115	parent->ReplaceChildLink(leaf, interior);
1116	interior->SetParent(parent);
1117	}
1118	else // new root
1119	{
1120	mRoot = interior;
1121	}
1122
1123	// and setup child links
1124	interior->SetupChildLinks(new BspLeaf(interior), new BspLeaf(interior));
1125
1126	frontData.mNode = interior->GetFront();
1127	backData.mNode = interior->GetBack();
1128
1129	frontData.mNode->mTimeStamp = mTimeStamp;
1130	backData.mNode->mTimeStamp = mTimeStamp ++;
1131
1132	//DEL_PTR(leaf);
1133	return interior;
1134	}
1135
1136
1137	void BspTree::SortSplitCandidates(const PolygonContainer &polys,
1138	const int axis,
1139	vector<SortableEntry> &splitCandidates) const
1140	{
1141	splitCandidates.clear();
1142
1143	int requestedSize = 2 * (int)polys.size();
1144	// creates a sorted split candidates array
1145	splitCandidates.reserve(requestedSize);
1146
1147	PolygonContainer::const_iterator it, it_end = polys.end();
1148
1149	AxisAlignedBox3 box;
1150
1151	// insert all queries
1152	for(it = polys.begin(); it != it_end; ++ it)
1153	{
1154	box.Initialize();
1155	box.Include((it));
1156
1157	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MIN, box.Min(axis), *it));
1158	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MAX, box.Max(axis), *it));
1159	}
1160
1161	stable_sort(splitCandidates.begin(), splitCandidates.end());
1162	}
1163
1164
1165	float BspTree::BestCostRatio(const PolygonContainer &polys,
1166	const AxisAlignedBox3 &box,
1167	const int axis,
1168	float &position,
1169	int &objectsBack,
1170	int &objectsFront) const
1171	{
1172	vector<SortableEntry> splitCandidates;
1173
1174	SortSplitCandidates(polys, axis, splitCandidates);
1175
1176	// go through the lists, count the number of objects left and right
1177	// and evaluate the following cost funcion:
1178	// C = ct_div_ci + (ol + or)/queries
1179
1180	int objectsLeft = 0, objectsRight = (int)polys.size();
1181
1182	float minBox = box.Min(axis);
1183	float maxBox = box.Max(axis);
1184	float boxArea = box.SurfaceArea();
1185
1186	float minBand = minBox + mSplitBorder * (maxBox - minBox);
1187	float maxBand = minBox + (1.0f - mSplitBorder) * (maxBox - minBox);
1188
1189	float minSum = 1e20f;
1190	vector<SortableEntry>::const_iterator ci, ci_end = splitCandidates.end();
1191
1192	for(ci = splitCandidates.begin(); ci != ci_end; ++ ci)
1193	{
1194	switch ((*ci).type)
1195	{
1196	case SortableEntry::POLY_MIN:
1197	++ objectsLeft;
1198	break;
1199	case SortableEntry::POLY_MAX:
1200	-- objectsRight;
1201	break;
1202	default:
1203	break;
1204	}
1205
1206	if ((ci).value > minBand && (ci).value < maxBand)
1207	{
1208	AxisAlignedBox3 lbox = box;
1209	AxisAlignedBox3 rbox = box;
1210	lbox.SetMax(axis, (*ci).value);
1211	rbox.SetMin(axis, (*ci).value);
1212
1213	const float sum = objectsLeft * lbox.SurfaceArea() +
1214	objectsRight * rbox.SurfaceArea();
1215
1216	if (sum < minSum)
1217	{
1218	minSum = sum;
1219	position = (*ci).value;
1220
1221	objectsBack = objectsLeft;
1222	objectsFront = objectsRight;
1223	}
1224	}
1225	}
1226
1227	const float oldCost = (float)polys.size();
1228	const float newCost = mAxisAlignedCtDivCi + minSum / boxArea;
1229	const float ratio = newCost / oldCost;
1230
1231
1232	#if 0
1233	Debug << "====================" << endl;
1234	Debug << "costRatio=" << ratio << " pos=" << position<<" t=" << (position - minBox)/(maxBox - minBox)
1235	<< "\t o=(" << objectsBack << "," << objectsFront << ")" << endl;
1236	#endif
1237	return ratio;
1238	}
1239
1240	bool BspTree::SelectAxisAlignedPlane(Plane3 &plane,
1241	const PolygonContainer &polys) const
1242	{
1243	AxisAlignedBox3 box;
1244	box.Initialize();
1245
1246	// create bounding box of region
1247	Polygon3::IncludeInBox(polys, box);
1248
1249	int objectsBack = 0, objectsFront = 0;
1250	int axis = 0;
1251	float costRatio = MAX_FLOAT;
1252	Vector3 position;
1253
1254	//-- area subdivision
1255	for (int i = 0; i < 3; ++ i)
1256	{
1257	float p = 0;
1258	float r = BestCostRatio(polys, box, i, p, objectsBack, objectsFront);
1259
1260	if (r < costRatio)
1261	{
1262	costRatio = r;
1263	axis = i;
1264	position = p;
1265	}
1266	}
1267
1268	if (costRatio >= mMaxCostRatio)
1269	return false;
1270
1271	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1272	plane = Plane3(norm, position);
1273
1274	return true;
1275	}
1276
1277
1278	Plane3 BspTree::SelectPlane(BspLeaf *leaf, BspTraversalData &data)
1279	{
1280	if (data.mPolygons->empty() && data.mRays->empty())
1281	{
1282	Debug << "Warning: No autopartition polygon candidate available\n";
1283
1284	// return axis aligned split
1285	AxisAlignedBox3 box;
1286	box.Initialize();
1287
1288	// create bounding box of region
1289	Polygon3::IncludeInBox(*data.mPolygons, box);
1290
1291	const int axis = box.Size().DrivingAxis();
1292	const Vector3 position = (box.Min()[axis] + box.Max()[axis]) * 0.5f;
1293
1294	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1295	return Plane3(norm, position);
1296	}
1297
1298	if ((mSplitPlaneStrategy & AXIS_ALIGNED) &&
1299	((int)data.mPolygons->size() > mTermMinPolysForAxisAligned) &&
1300	((int)data.mRays->size() > mTermMinRaysForAxisAligned) &&
1301	((mTermMinObjectsForAxisAligned < 0) \|\|
1302	(Polygon3::ParentObjectsSize(*data.mPolygons) > mTermMinObjectsForAxisAligned)))
1303	{
1304	Plane3 plane;
1305	if (SelectAxisAlignedPlane(plane, *data.mPolygons))
1306	return plane;
1307	}
1308
1309	// simplest strategy: just take next polygon
1310	if (mSplitPlaneStrategy & RANDOM_POLYGON)
1311	{
1312	if (!data.mPolygons->empty())
1313	{
1314	Polygon3 *nextPoly =
1315	(*data.mPolygons)[(int)RandomValue(0, (Real)((int)data.mPolygons->size() - 1))];
1316	return nextPoly->GetSupportingPlane();
1317	}
1318	else
1319	{
1320	const int candidateIdx = (int)RandomValue(0, (Real)((int)data.mRays->size() - 1));
1321	BoundedRay bRay = (data.mRays)[candidateIdx];
1322
1323	Ray *ray = bRay->mRay;
1324
1325	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1326	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1327
1328	const Vector3 pt = (maxPt + minPt) * 0.5;
1329
1330	const Vector3 normal = ray->GetDir();
1331
1332	return Plane3(normal, pt);
1333	}
1334
1335	return Plane3();
1336	}
1337
1338	// use heuristics to find appropriate plane
1339	return SelectPlaneHeuristics(leaf, data);
1340	}
1341
1342
1343	Plane3 BspTree::ChooseCandidatePlane(const BoundedRayContainer &rays) const
1344	{
1345	const int candidateIdx = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1346	BoundedRay *bRay = rays[candidateIdx];
1347	Ray *ray = bRay->mRay;
1348
1349	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1350	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1351
1352	const Vector3 pt = (maxPt + minPt) * 0.5;
1353
1354	const Vector3 normal = ray->GetDir();
1355
1356	return Plane3(normal, pt);
1357	}
1358
1359	Plane3 BspTree::ChooseCandidatePlane2(const BoundedRayContainer &rays) const
1360	{
1361	Vector3 pt[3];
1362	int idx[3];
1363	int cmaxT = 0;
1364	int cminT = 0;
1365	bool chooseMin = false;
1366
1367	for (int j = 0; j < 3; j ++)
1368	{
1369	idx[j] = (int)RandomValue(0, Real((int)rays.size() * 2 - 1));
1370
1371	if (idx[j] >= (int)rays.size())
1372	{
1373	idx[j] -= (int)rays.size();
1374	chooseMin = (cminT < 2);
1375	}
1376	else
1377	chooseMin = (cmaxT < 2);
1378
1379	BoundedRay *bRay = rays[idx[j]];
1380	pt[j] = chooseMin ? bRay->mRay->Extrap(bRay->mMinT) :
1381	bRay->mRay->Extrap(bRay->mMaxT);
1382	}
1383
1384	return Plane3(pt[0], pt[1], pt[2]);
1385	}
1386
1387	Plane3 BspTree::ChooseCandidatePlane3(const BoundedRayContainer &rays) const
1388	{
1389	Vector3 pt[3];
1390
1391	int idx1 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1392	int idx2 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1393
1394	// check if rays different
1395	if (idx1 == idx2)
1396	idx2 = (idx2 + 1) % (int)rays.size();
1397
1398	const BoundedRay *ray1 = rays[idx1];
1399	const BoundedRay *ray2 = rays[idx2];
1400
1401	// normal vector of the plane parallel to both lines
1402	const Vector3 norm =
1403	Normalize(CrossProd(ray1->mRay->GetDir(), ray2->mRay->GetDir()));
1404
1405	const Vector3 orig1 = ray1->mRay->Extrap(ray1->mMinT);
1406	const Vector3 orig2 = ray2->mRay->Extrap(ray2->mMinT);
1407
1408	// vector from line 1 to line 2
1409	const Vector3 vd = orig1 - orig2;
1410
1411	// project vector on normal to get distance
1412	const float dist = DotProd(vd, norm);
1413
1414	// point on plane lies halfway between the two planes
1415	const Vector3 planePt = orig1 + norm * dist * 0.5;
1416
1417	return Plane3(norm, planePt);
1418	}
1419
1420
1421	Plane3 BspTree::SelectPlaneHeuristics(BspLeaf *leaf, BspTraversalData &data)
1422	{
1423	float lowestCost = MAX_FLOAT;
1424	Plane3 bestPlane;
1425	// intermediate plane
1426	Plane3 plane;
1427
1428	const int limit = Min((int)data.mPolygons->size(), mMaxPolyCandidates);
1429	int maxIdx = (int)data.mPolygons->size();
1430
1431	for (int i = 0; i < limit; ++ i)
1432	{
1433	// assure that no index is taken twice
1434	const int candidateIdx = (int)RandomValue(0, (Real)(-- maxIdx));
1435
1436	Polygon3 poly = (data.mPolygons)[candidateIdx];
1437
1438	// swap candidate to the end to avoid testing same plane
1439	std::swap((data.mPolygons)[maxIdx], (data.mPolygons)[candidateIdx]);
1440	//Polygon3 poly = (data.mPolygons)[(int)RandomValue(0, (int)polys.size() - 1)];
1441
1442	// evaluate current candidate
1443	const float candidateCost =
1444	SplitPlaneCost(poly->GetSupportingPlane(), data);
1445
1446	if (candidateCost < lowestCost)
1447	{
1448	bestPlane = poly->GetSupportingPlane();
1449	lowestCost = candidateCost;
1450	}
1451	}
1452
1453	//-- choose candidate planes extracted from rays
1454	for (int i = 0; i < mMaxRayCandidates; ++ i)
1455	{
1456	plane = ChooseCandidatePlane3(*data.mRays);
1457	const float candidateCost = SplitPlaneCost(plane, data);
1458
1459	if (candidateCost < lowestCost)
1460	{
1461	bestPlane = plane;
1462	lowestCost = candidateCost;
1463	}
1464	}
1465
1466	#ifdef _DEBUG
1467	Debug << "plane lowest cost: " << lowestCost << endl;
1468	#endif
1469
1470	return bestPlane;
1471	}
1472
1473
1474	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1475	const PolygonContainer &polys) const
1476	{
1477	float val = 0;
1478
1479	float sumBalancedPolys = 0;
1480	float sumSplits = 0;
1481	float sumPolyArea = 0;
1482	float sumBalancedViewCells = 0;
1483	float sumBlockedRays = 0;
1484	float totalBlockedRays = 0;
1485	//float totalArea = 0;
1486	int totalViewCells = 0;
1487
1488	// need three unique ids for each type of view cell
1489	// for balanced view cells criterium
1490	ViewCell::NewMail();
1491	const int backId = ViewCell::sMailId;
1492	ViewCell::NewMail();
1493	const int frontId = ViewCell::sMailId;
1494	ViewCell::NewMail();
1495	const int frontAndBackId = ViewCell::sMailId;
1496
1497	bool useRand;;
1498	int limit;
1499
1500	// choose test polyongs randomly if over threshold
1501	if ((int)polys.size() > mMaxTests)
1502	{
1503	useRand = true;
1504	limit = mMaxTests;
1505	}
1506	else
1507	{
1508	useRand = false;
1509	limit = (int)polys.size();
1510	}
1511
1512	for (int i = 0; i < limit; ++ i)
1513	{
1514	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1515
1516	Polygon3 *poly = polys[testIdx];
1517
1518	const int classification =
1519	poly->ClassifyPlane(candidatePlane, mEpsilon);
1520
1521	if (mSplitPlaneStrategy & BALANCED_POLYS)
1522	sumBalancedPolys += sBalancedPolysTable[classification];
1523
1524	if (mSplitPlaneStrategy & LEAST_SPLITS)
1525	sumSplits += sLeastPolySplitsTable[classification];
1526
1527	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1528	{
1529	if (classification == Polygon3::COINCIDENT)
1530	sumPolyArea += poly->GetArea();
1531	//totalArea += area;
1532	}
1533
1534	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1535	{
1536	const float blockedRays = (float)poly->mPiercingRays.size();
1537
1538	if (classification == Polygon3::COINCIDENT)
1539	sumBlockedRays += blockedRays;
1540
1541	totalBlockedRays += blockedRays;
1542	}
1543
1544	// assign view cells to back or front according to classificaion
1545	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1546	{
1547	MeshInstance *viewCell = poly->mParent;
1548
1549	// assure that we only count a view cell
1550	// once for the front and once for the back side of the plane
1551	if (classification == Polygon3::FRONT_SIDE)
1552	{
1553	if ((viewCell->mMailbox != frontId) &&
1554	(viewCell->mMailbox != frontAndBackId))
1555	{
1556	sumBalancedViewCells += 1.0;
1557
1558	if (viewCell->mMailbox != backId)
1559	viewCell->mMailbox = frontId;
1560	else
1561	viewCell->mMailbox = frontAndBackId;
1562
1563	++ totalViewCells;
1564	}
1565	}
1566	else if (classification == Polygon3::BACK_SIDE)
1567	{
1568	if ((viewCell->mMailbox != backId) &&
1569	(viewCell->mMailbox != frontAndBackId))
1570	{
1571	sumBalancedViewCells -= 1.0;
1572
1573	if (viewCell->mMailbox != frontId)
1574	viewCell->mMailbox = backId;
1575	else
1576	viewCell->mMailbox = frontAndBackId;
1577
1578	++ totalViewCells;
1579	}
1580	}
1581	}
1582	}
1583
1584	const float polysSize = (float)polys.size() + Limits::Small;
1585
1586	// all values should be approx. between 0 and 1 so they can be combined
1587	// and scaled with the factors according to their importance
1588	if (mSplitPlaneStrategy & BALANCED_POLYS)
1589	val += mBalancedPolysFactor * fabs(sumBalancedPolys) / polysSize;
1590
1591	if (mSplitPlaneStrategy & LEAST_SPLITS)
1592	val += mLeastSplitsFactor * sumSplits / polysSize;
1593
1594	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1595	// HACK: polys.size should be total area so scaling is between 0 and 1
1596	val += mLargestPolyAreaFactor * (float)polys.size() / sumPolyArea;
1597
1598	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1599	if (totalBlockedRays != 0)
1600	val += mBlockedRaysFactor * (totalBlockedRays - sumBlockedRays) / totalBlockedRays;
1601
1602	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1603	val += mBalancedViewCellsFactor * fabs(sumBalancedViewCells) /
1604	((float)totalViewCells + Limits::Small);
1605
1606	return val;
1607	}
1608
1609
1610	inline void BspTree::GenerateUniqueIdsForPvs()
1611	{
1612	ViewCell::NewMail(); sBackId = ViewCell::sMailId;
1613	ViewCell::NewMail(); sFrontId = ViewCell::sMailId;
1614	ViewCell::NewMail(); sFrontAndBackId = ViewCell::sMailId;
1615	}
1616
1617
1618	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1619	const BoundedRayContainer &rays,
1620	const int pvs,
1621	const float probability,
1622	const BspNodeGeometry &cell) const
1623	{
1624	float val = 0;
1625
1626	float sumBalancedRays = 0;
1627	float sumRaySplits = 0;
1628
1629	int frontPvs = 0;
1630	int backPvs = 0;
1631
1632	// probability that view point lies in child
1633	float pOverall = 0;
1634	float pFront = 0;
1635	float pBack = 0;
1636
1637	const bool pvsUseLen = false;
1638
1639	if (mSplitPlaneStrategy & PVS)
1640	{
1641	// create unique ids for pvs heuristics
1642	GenerateUniqueIdsForPvs();
1643
1644	// construct child geometry with regard to the candidate split plane
1645	BspNodeGeometry frontCell;
1646	BspNodeGeometry backCell;
1647
1648	cell.SplitGeometry(frontCell,
1649	backCell,
1650	candidatePlane,
1651	mBox,
1652	mEpsilon);
1653
1654	if (mUseAreaForPvs)
1655	{
1656	pFront = frontCell.GetArea();
1657	pBack = backCell.GetArea();
1658	}
1659	else
1660	{
1661	pFront = frontCell.GetVolume();
1662	pBack = pOverall - pFront;
1663	}
1664
1665
1666	pOverall = probability;
1667	}
1668
1669	bool useRand;
1670	int limit;
1671
1672	// choose test polyongs randomly if over threshold
1673	if ((int)rays.size() > mMaxTests)
1674	{
1675	useRand = true;
1676	limit = mMaxTests;
1677	}
1678	else
1679	{
1680	useRand = false;
1681	limit = (int)rays.size();
1682	}
1683
1684	for (int i = 0; i < limit; ++ i)
1685	{
1686	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1687
1688	BoundedRay *bRay = rays[testIdx];
1689
1690	Ray *ray = bRay->mRay;
1691	const float minT = bRay->mMinT;
1692	const float maxT = bRay->mMaxT;
1693
1694	Vector3 entP, extP;
1695
1696	const int cf =
1697	ray->ClassifyPlane(candidatePlane, minT, maxT, entP, extP);
1698
1699	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1700	{
1701	sumBalancedRays += sBalancedRaysTable[cf];
1702	}
1703
1704	if (mSplitPlaneStrategy & BALANCED_RAYS)
1705	{
1706	sumRaySplits += sLeastRaySplitsTable[cf];
1707	}
1708
1709	if (mSplitPlaneStrategy & PVS)
1710	{
1711	// in case the ray intersects an object
1712	// assure that we only count the object
1713	// once for the front and once for the back side of the plane
1714
1715	// add the termination object
1716	if (!ray->intersections.empty())
1717	AddObjToPvs(ray->intersections[0].mObject, cf, frontPvs, backPvs);
1718
1719	// add the source object
1720	AddObjToPvs(ray->sourceObject.mObject, cf, frontPvs, backPvs);
1721	}
1722	}
1723
1724	const float raysSize = (float)rays.size() + Limits::Small;
1725
1726	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1727	val += mLeastRaySplitsFactor * sumRaySplits / raysSize;
1728
1729	if (mSplitPlaneStrategy & BALANCED_RAYS)
1730	val += mBalancedRaysFactor * fabs(sumBalancedRays) / raysSize;
1731
1732	const float denom = pOverall * (float)pvs * 2.0f + Limits::Small;
1733
1734	if (mSplitPlaneStrategy & PVS)
1735	{
1736	val += mPvsFactor * (frontPvs * pFront + (backPvs * pBack)) / denom;
1737
1738	// give penalty to unbalanced split
1739	if (0)
1740	if (((pFront * 0.2 + Limits::Small) > pBack) \|\|
1741	(pFront < (pBack * 0.2 + Limits::Small)))
1742	val += 0.5;
1743	}
1744
1745
1746	#ifdef _DEBUG
1747	Debug << "totalpvs: " << pvs << " ptotal: " << pOverall
1748	<< " frontpvs: " << frontPvs << " pFront: " << pFront
1749	<< " backpvs: " << backPvs << " pBack: " << pBack << endl << endl;
1750	#endif
1751
1752	return val;
1753	}
1754
1755	void BspTree::AddObjToPvs(Intersectable *obj,
1756	const int cf,
1757	int &frontPvs,
1758	int &backPvs) const
1759	{
1760	if (!obj)
1761	return;
1762	// TODO: does this really belong to no pvs?
1763	//if (cf == Ray::COINCIDENT) return;
1764
1765	// object belongs to both PVS
1766	const bool bothSides = (cf == Ray::FRONT_BACK) \|\|
1767	(cf == Ray::BACK_FRONT) \|\|
1768	(cf == Ray::COINCIDENT);
1769
1770	if ((cf == Ray::FRONT) \|\| bothSides)
1771	{
1772	if ((obj->mMailbox != sFrontId) &&
1773	(obj->mMailbox != sFrontAndBackId))
1774	{
1775	++ frontPvs;
1776
1777	if (obj->mMailbox == sBackId)
1778	obj->mMailbox = sFrontAndBackId;
1779	else
1780	obj->mMailbox = sFrontId;
1781	}
1782	}
1783
1784	if ((cf == Ray::BACK) \|\| bothSides)
1785	{
1786	if ((obj->mMailbox != sBackId) &&
1787	(obj->mMailbox != sFrontAndBackId))
1788	{
1789	++ backPvs;
1790
1791	if (obj->mMailbox == sFrontId)
1792	obj->mMailbox = sFrontAndBackId;
1793	else
1794	obj->mMailbox = sBackId;
1795	}
1796	}
1797	}
1798
1799	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1800	BspTraversalData &data) const
1801	{
1802	float val = 0;
1803
1804	if (mSplitPlaneStrategy & VERTICAL_AXIS)
1805	{
1806	Vector3 tinyAxis(0,0,0); tinyAxis[mBox.Size().TinyAxis()] = 1.0f;
1807	// we put a penalty on the dot product between the "tiny" vertical axis
1808	// and the split plane axis
1809	val += mVerticalSplitsFactor *
1810	fabs(DotProd(candidatePlane.mNormal, tinyAxis));
1811	}
1812
1813	// the following criteria loop over all polygons to find the cost value
1814	if ((mSplitPlaneStrategy & BALANCED_POLYS) \|\|
1815	(mSplitPlaneStrategy & LEAST_SPLITS) \|\|
1816	(mSplitPlaneStrategy & LARGEST_POLY_AREA) \|\|
1817	(mSplitPlaneStrategy & BALANCED_VIEW_CELLS) \|\|
1818	(mSplitPlaneStrategy & BLOCKED_RAYS))
1819	{
1820	val += SplitPlaneCost(candidatePlane, *data.mPolygons);
1821	}
1822
1823	// the following criteria loop over all rays to find the cost value
1824	if ((mSplitPlaneStrategy & BALANCED_RAYS) \|\|
1825	(mSplitPlaneStrategy & LEAST_RAY_SPLITS) \|\|
1826	(mSplitPlaneStrategy & PVS))
1827	{
1828	val += SplitPlaneCost(candidatePlane, *data.mRays, data.mPvs,
1829	data.mProbability, *data.mGeometry);
1830	}
1831
1832	// return linear combination of the sums
1833	return val;
1834	}
1835
1836	void BspTree::CollectLeaves(vector<BspLeaf *> &leaves) const
1837	{
1838	stack<BspNode *> nodeStack;
1839	nodeStack.push(mRoot);
1840
1841	while (!nodeStack.empty())
1842	{
1843	BspNode *node = nodeStack.top();
1844
1845	nodeStack.pop();
1846
1847	if (node->IsLeaf())
1848	{
1849	BspLeaf leaf = (BspLeaf )node;
1850	leaves.push_back(leaf);
1851	}
1852	else
1853	{
1854	BspInterior interior = dynamic_cast<BspInterior >(node);
1855
1856	nodeStack.push(interior->GetBack());
1857	nodeStack.push(interior->GetFront());
1858	}
1859	}
1860	}
1861
1862
1863	AxisAlignedBox3 BspTree::GetBoundingBox() const
1864	{
1865	return mBox;
1866	}
1867
1868
1869	void BspTree::EvaluateLeafStats(const BspTraversalData &data)
1870	{
1871	// the node became a leaf -> evaluate stats for leafs
1872	BspLeaf leaf = dynamic_cast<BspLeaf >(data.mNode);
1873
1874	// store maximal and minimal depth
1875	if (data.mDepth > mStat.maxDepth)
1876	mStat.maxDepth = data.mDepth;
1877
1878	if (data.mDepth < mStat.minDepth)
1879	mStat.minDepth = data.mDepth;
1880
1881	// accumulate depth to compute average depth
1882	mStat.accumDepth += data.mDepth;
1883	// accumulate rays to compute rays / leaf
1884	mStat.accumRays += (int)data.mRays->size();
1885
1886	if (data.mDepth >= mTermMaxDepth)
1887	++ mStat.maxDepthNodes;
1888
1889	if (data.mPvs < mTermMinPvs)
1890	++ mStat.minPvsNodes;
1891
1892	if ((int)data.mRays->size() < mTermMinRays)
1893	++ mStat.minRaysNodes;
1894
1895	if (data.GetAvgRayContribution() > mTermMaxRayContribution)
1896	++ mStat.maxRayContribNodes;
1897
1898	if (data.mProbability <= mTermMinProbability)
1899	++ mStat.minProbabilityNodes;
1900
1901	#ifdef _DEBUG
1902	Debug << "BSP stats: "
1903	<< "Depth: " << data.mDepth << " (max: " << mTermMaxDepth << "), "
1904	<< "PVS: " << data.mPvs << " (min: " << mTermMinPvs << "), "
1905	<< "Probability: " << data.mProbability << " (min: " << mTermMinProbability << "), "
1906	<< "#polygons: " << (int)data.mPolygons->size() << " (max: " << mTermMinPolys << "), "
1907	<< "#rays: " << (int)data.mRays->size() << " (max: " << mTermMinRays << "), "
1908	<< "#pvs: " << leaf->GetViewCell()->GetPvs().GetSize() << "=, "
1909	<< "#avg ray contrib (pvs): " << (float)data.mPvs / (float)data.mRays->size() << endl;
1910	#endif
1911	}
1912
1913	int
1914	BspTree::_CastRay(Ray &ray)
1915	{
1916	int hits = 0;
1917
1918	stack<BspRayTraversalData> tStack;
1919
1920	float maxt, mint;
1921
1922	if (!mBox.GetRaySegment(ray, mint, maxt))
1923	return 0;
1924
1925	ViewCell::NewMail();
1926
1927	Vector3 entp = ray.Extrap(mint);
1928	Vector3 extp = ray.Extrap(maxt);
1929
1930	BspNode *node = mRoot;
1931	BspNode *farChild = NULL;
1932
1933	while (1)
1934	{
1935	if (!node->IsLeaf())
1936	{
1937	BspInterior in = dynamic_cast<BspInterior >(node);
1938
1939	Plane3 splitPlane = in->GetPlane();
1940	const int entSide = splitPlane.Side(entp);
1941	const int extSide = splitPlane.Side(extp);
1942
1943	if (entSide < 0)
1944	{
1945	node = in->GetBack();
1946
1947	if(extSide <= 0) // plane does not split ray => no far child
1948	continue;
1949
1950	farChild = in->GetFront(); // plane splits ray
1951
1952	} else if (entSide > 0)
1953	{
1954	node = in->GetFront();
1955
1956	if (extSide >= 0) // plane does not split ray => no far child
1957	continue;
1958
1959	farChild = in->GetBack(); // plane splits ray
1960	}
1961	else // ray and plane are coincident
1962	{
1963	// WHAT TO DO IN THIS CASE ?
1964	//break;
1965	node = in->GetFront();
1966	continue;
1967	}
1968
1969	// push data for far child
1970	tStack.push(BspRayTraversalData(farChild, extp, maxt));
1971
1972	// find intersection of ray segment with plane
1973	float t;
1974	extp = splitPlane.FindIntersection(ray.GetLoc(), extp, &t);
1975	maxt *= t;
1976
1977	} else // reached leaf => intersection with view cell
1978	{
1979	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
1980
1981	if (!leaf->mViewCell->Mailed())
1982	{
1983	// ray.bspIntersections.push_back(Ray::BspIntersection(maxt, leaf));
1984	leaf->mViewCell->Mail();
1985	++ hits;
1986	}
1987
1988	//-- fetch the next far child from the stack
1989	if (tStack.empty())
1990	break;
1991
1992	entp = extp;
1993	mint = maxt; // NOTE: need this?
1994
1995	if (ray.GetType() == Ray::LINE_SEGMENT && mint > 1.0f)
1996	break;
1997
1998	BspRayTraversalData &s = tStack.top();
1999
2000	node = s.mNode;
2001	extp = s.mExitPoint;
2002	maxt = s.mMaxT;
2003
2004	tStack.pop();
2005	}
2006	}
2007
2008	return hits;
2009	}
2010
2011
2012	int BspTree::CastLineSegment(const Vector3 &origin,
2013	const Vector3 &termination,
2014	vector<ViewCell *> &viewcells)
2015	{
2016	int hits = 0;
2017	stack<BspRayTraversalData> tStack;
2018
2019	float mint = 0.0f, maxt = 1.0f;
2020
2021	Intersectable::NewMail();
2022	ViewCell::NewMail();
2023
2024	Vector3 entp = origin;
2025	Vector3 extp = termination;
2026
2027	BspNode *node = mRoot;
2028	BspNode *farChild = NULL;
2029
2030	while (1)
2031	{
2032	if (!node->IsLeaf())
2033	{
2034	BspInterior in = dynamic_cast<BspInterior >(node);
2035
2036	Plane3 splitPlane = in->GetPlane();
2037
2038	const int entSide = splitPlane.Side(entp);
2039	const int extSide = splitPlane.Side(extp);
2040
2041	if (entSide < 0)
2042	{
2043	node = in->GetBack();
2044
2045	if(extSide <= 0) // plane does not split ray => no far child
2046	continue;
2047
2048	farChild = in->GetFront(); // plane splits ray
2049
2050	}
2051	else if (entSide > 0)
2052	{
2053	node = in->GetFront();
2054
2055	if (extSide >= 0) // plane does not split ray => no far child
2056	continue;
2057
2058	farChild = in->GetBack(); // plane splits ray
2059	}
2060	else // ray and plane are coincident
2061	{
2062	// WHAT TO DO IN THIS CASE ?
2063	//break;
2064	node = in->GetFront();
2065	continue;
2066	}
2067
2068	// push data for far child
2069	tStack.push(BspRayTraversalData(farChild, extp, maxt));
2070
2071	// find intersection of ray segment with plane
2072	float t;
2073	extp = splitPlane.FindIntersection(origin, extp, &t);
2074	maxt *= t;
2075	}
2076	else
2077	{
2078	// reached leaf => intersection with view cell
2079	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
2080
2081	if (!leaf->mViewCell->Mailed())
2082	{
2083	viewcells.push_back(leaf->mViewCell);
2084	leaf->mViewCell->Mail();
2085	hits++;
2086	}
2087
2088	//-- fetch the next far child from the stack
2089	if (tStack.empty())
2090	break;
2091
2092	entp = extp;
2093	mint = maxt; // NOTE: need this?
2094
2095	BspRayTraversalData &s = tStack.top();
2096
2097	node = s.mNode;
2098	extp = s.mExitPoint;
2099	maxt = s.mMaxT;
2100
2101	tStack.pop();
2102	}
2103	}
2104	return hits;
2105	}
2106
2107
2108	void BspTree::CollectViewCells(ViewCellContainer &viewCells) const
2109	{
2110	stack<BspNode *> nodeStack;
2111	nodeStack.push(mRoot);
2112
2113	ViewCell::NewMail();
2114
2115	while (!nodeStack.empty())
2116	{
2117	BspNode *node = nodeStack.top();
2118	nodeStack.pop();
2119
2120	if (node->IsLeaf())
2121	{
2122	ViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
2123
2124	if (!viewCell->Mailed())
2125	{
2126	viewCell->Mail();
2127	viewCells.push_back(viewCell);
2128	}
2129	}
2130	else
2131	{
2132	BspInterior interior = dynamic_cast<BspInterior >(node);
2133
2134	nodeStack.push(interior->GetFront());
2135	nodeStack.push(interior->GetBack());
2136	}
2137	}
2138	}
2139
2140
2141	BspTreeStatistics &BspTree::GetStat()
2142	{
2143	return mStat;
2144	}
2145
2146
2147	float BspTree::AccumulatedRayLength(BoundedRayContainer &rays) const
2148	{
2149	float len = 0;
2150
2151	BoundedRayContainer::const_iterator it, it_end = rays.end();
2152
2153	for (it = rays.begin(); it != it_end; ++ it)
2154	{
2155	len += SqrDistance((it)->mRay->Extrap((it)->mMinT),
2156	(it)->mRay->Extrap((it)->mMaxT));
2157	}
2158
2159	return len;
2160	}
2161
2162
2163	int BspTree::SplitRays(const Plane3 &plane,
2164	BoundedRayContainer &rays,
2165	BoundedRayContainer &frontRays,
2166	BoundedRayContainer &backRays)
2167	{
2168	int splits = 0;
2169
2170	while (!rays.empty())
2171	{
2172	BoundedRay *bRay = rays.back();
2173	Ray *ray = bRay->mRay;
2174	float minT = bRay->mMinT;
2175	float maxT = bRay->mMaxT;
2176
2177	rays.pop_back();
2178
2179	Vector3 entP, extP;
2180
2181	const int cf =
2182	ray->ClassifyPlane(plane, minT, maxT, entP, extP);
2183
2184	// set id to ray classification
2185	ray->SetId(cf);
2186
2187	switch (cf)
2188	{
2189	case Ray::COINCIDENT: // TODO: should really discard ray?
2190	frontRays.push_back(bRay);
2191	//DEL_PTR(bRay);
2192	break;
2193	case Ray::BACK:
2194	backRays.push_back(bRay);
2195	break;
2196	case Ray::FRONT:
2197	frontRays.push_back(bRay);
2198	break;
2199	case Ray::FRONT_BACK:
2200	{
2201	// find intersection of ray segment with plane
2202	const float t = plane.FindT(ray->GetLoc(), extP);
2203
2204	const float newT = t * maxT;
2205
2206	frontRays.push_back(new BoundedRay(ray, minT, newT));
2207	backRays.push_back(new BoundedRay(ray, newT, maxT));
2208
2209	DEL_PTR(bRay);
2210	}
2211	break;
2212	case Ray::BACK_FRONT:
2213	{
2214	// find intersection of ray segment with plane
2215	const float t = plane.FindT(ray->GetLoc(), extP);
2216	const float newT = t * bRay->mMaxT;
2217
2218	backRays.push_back(new BoundedRay(ray, minT, newT));
2219	frontRays.push_back(new BoundedRay(ray, newT, maxT));
2220
2221	DEL_PTR(bRay);
2222
2223	++ splits;
2224	}
2225	break;
2226	default:
2227	Debug << "Should not come here 4" << endl;
2228	break;
2229	}
2230	}
2231
2232	return splits;
2233	}
2234
2235	void BspTree::ExtractHalfSpaces(BspNode *n, vector<Plane3> &halfSpaces) const
2236	{
2237	BspNode *lastNode;
2238	do
2239	{
2240	lastNode = n;
2241
2242	// want to get planes defining geometry of this node => don't take
2243	// split plane of node itself
2244	n = n->GetParent();
2245
2246	if (n)
2247	{
2248	BspInterior interior = dynamic_cast<BspInterior >(n);
2249	Plane3 halfSpace = dynamic_cast<BspInterior *>(interior)->GetPlane();
2250
2251	if (interior->GetFront() != lastNode)
2252	halfSpace.ReverseOrientation();
2253
2254	halfSpaces.push_back(halfSpace);
2255	}
2256	}
2257	while (n);
2258	}
2259
2260
2261
2262	void BspTree::ConstructGeometry(ViewCell *vc,
2263	BspNodeGeometry &vcGeom) const
2264	{
2265	ViewCellContainer leaves;
2266	mViewCellsTree->CollectLeaves(vc, leaves);
2267
2268	ViewCellContainer::const_iterator it, it_end = leaves.end();
2269
2270	for (it = leaves.begin(); it != it_end; ++ it)
2271	{
2272	BspLeaf l = dynamic_cast<BspViewCell >(*it)->mLeaf;
2273	ConstructGeometry(l, vcGeom);
2274	}
2275	}
2276
2277
2278	void BspTree::SetViewCellsManager(ViewCellsManager *vcm)
2279	{
2280	mViewCellsManager = vcm;
2281	}
2282
2283
2284	void BspTree::ConstructGeometry(BspNode *n, BspNodeGeometry &geom) const
2285	{
2286	vector<Plane3> halfSpaces;
2287	ExtractHalfSpaces(n, halfSpaces);
2288
2289	PolygonContainer candidates;
2290
2291	// bounded planes are added to the polygons (reverse polygons
2292	// as they have to be outfacing
2293	for (int i = 0; i < (int)halfSpaces.size(); ++ i)
2294	{
2295	Polygon3 *p = GetBoundingBox().CrossSection(halfSpaces[i]);
2296
2297	if (p->Valid(mEpsilon))
2298	{
2299	candidates.push_back(p->CreateReversePolygon());
2300	DEL_PTR(p);
2301	}
2302	}
2303
2304	// add faces of bounding box (also could be faces of the cell)
2305	for (int i = 0; i < 6; ++ i)
2306	{
2307	VertexContainer vertices;
2308
2309	for (int j = 0; j < 4; ++ j)
2310	vertices.push_back(mBox.GetFace(i).mVertices[j]);
2311
2312	candidates.push_back(new Polygon3(vertices));
2313	}
2314
2315	for (int i = 0; i < (int)candidates.size(); ++ i)
2316	{
2317	// polygon is split by all other planes
2318	for (int j = 0; (j < (int)halfSpaces.size()) && candidates[i]; ++ j)
2319	{
2320	if (i == j) // polygon and plane are coincident
2321	continue;
2322
2323	VertexContainer splitPts;
2324	Polygon3 frontPoly, backPoly;
2325
2326	const int cf = candidates[i]->
2327	ClassifyPlane(halfSpaces[j], mEpsilon);
2328
2329	switch (cf)
2330	{
2331	case Polygon3::SPLIT:
2332	frontPoly = new Polygon3();
2333	backPoly = new Polygon3();
2334
2335	candidates[i]->Split(halfSpaces[j],
2336	*frontPoly,
2337	*backPoly,
2338	mEpsilon);
2339
2340	DEL_PTR(candidates[i]);
2341
2342	if (frontPoly->Valid(mEpsilon))
2343	candidates[i] = frontPoly;
2344	else
2345	DEL_PTR(frontPoly);
2346
2347	DEL_PTR(backPoly);
2348	break;
2349	case Polygon3::BACK_SIDE:
2350	DEL_PTR(candidates[i]);
2351	break;
2352	// just take polygon as it is
2353	case Polygon3::FRONT_SIDE:
2354	case Polygon3::COINCIDENT:
2355	default:
2356	break;
2357	}
2358	}
2359
2360	if (candidates[i])
2361	geom.mPolys.push_back(candidates[i]);
2362	}
2363	}
2364
2365
2366	typedef pair<BspNode , BspNodeGeometry > bspNodePair;
2367
2368
2369	int BspTree::FindNeighbors(BspNode n, vector<BspLeaf > &neighbors,
2370	const bool onlyUnmailed) const
2371	{
2372	stack<bspNodePair> nodeStack;
2373
2374	BspNodeGeometry nodeGeom;
2375	ConstructGeometry(n, nodeGeom);
2376
2377	// split planes from the root to this node
2378	// needed to verify that we found neighbor leaf
2379	// TODO: really needed?
2380	vector<Plane3> halfSpaces;
2381	ExtractHalfSpaces(n, halfSpaces);
2382
2383
2384	BspNodeGeometry *rgeom = new BspNodeGeometry();
2385	ConstructGeometry(mRoot, *rgeom);
2386
2387	nodeStack.push(bspNodePair(mRoot, rgeom));
2388
2389	while (!nodeStack.empty())
2390	{
2391	BspNode *node = nodeStack.top().first;
2392	BspNodeGeometry *geom = nodeStack.top().second;
2393
2394	nodeStack.pop();
2395
2396	if (node->IsLeaf())
2397	{
2398	// test if this leaf is in valid view space
2399	if (node->TreeValid() &&
2400	(node != n) &&
2401	(!onlyUnmailed \|\| !node->Mailed()))
2402	{
2403	bool isAdjacent = true;
2404
2405	if (1)
2406	{
2407	// test all planes of current node if still adjacent
2408	for (int i = 0; (i < halfSpaces.size()) && isAdjacent; ++ i)
2409	{
2410	const int cf =
2411	Polygon3::ClassifyPlane(geom->mPolys,
2412	halfSpaces[i],
2413	mEpsilon);
2414
2415	if (cf == Polygon3::BACK_SIDE)
2416	{
2417	isAdjacent = false;
2418	}
2419	}
2420	}
2421	else
2422	{
2423	// TODO: why is this wrong??
2424	// test all planes of current node if still adjacent
2425	for (int i = 0; (i < (int)nodeGeom.mPolys.size()) && isAdjacent; ++ i)
2426	{
2427	Polygon3 *poly = nodeGeom.mPolys[i];
2428
2429	const int cf =
2430	Polygon3::ClassifyPlane(geom->mPolys,
2431	poly->GetSupportingPlane(),
2432	mEpsilon);
2433
2434	if (cf == Polygon3::BACK_SIDE)
2435	{
2436	isAdjacent = false;
2437	}
2438	}
2439	}
2440	// neighbor was found
2441	if (isAdjacent)
2442	{
2443	neighbors.push_back(dynamic_cast<BspLeaf *>(node));
2444	}
2445	}
2446	}
2447	else
2448	{
2449	BspInterior interior = dynamic_cast<BspInterior >(node);
2450
2451	const int cf = Polygon3::ClassifyPlane(nodeGeom.mPolys,
2452	interior->GetPlane(),
2453	mEpsilon);
2454
2455	BspNode *front = interior->GetFront();
2456	BspNode *back = interior->GetBack();
2457
2458	BspNodeGeometry *fGeom = new BspNodeGeometry();
2459	BspNodeGeometry *bGeom = new BspNodeGeometry();
2460
2461	geom->SplitGeometry(*fGeom,
2462	*bGeom,
2463	interior->GetPlane(),
2464	mBox,
2465	mEpsilon);
2466
2467	if (cf == Polygon3::FRONT_SIDE)
2468	{
2469	nodeStack.push(bspNodePair(interior->GetFront(), fGeom));
2470	DEL_PTR(bGeom);
2471	}
2472	else
2473	{
2474	if (cf == Polygon3::BACK_SIDE)
2475	{
2476	nodeStack.push(bspNodePair(interior->GetBack(), bGeom));
2477	DEL_PTR(fGeom);
2478	}
2479	else
2480	{ // random decision
2481	nodeStack.push(bspNodePair(front, fGeom));
2482	nodeStack.push(bspNodePair(back, bGeom));
2483	}
2484	}
2485	}
2486
2487	DEL_PTR(geom);
2488	}
2489
2490	return (int)neighbors.size();
2491	}
2492
2493
2494	BspLeaf *BspTree::GetRandomLeaf(const Plane3 &halfspace)
2495	{
2496	stack<BspNode *> nodeStack;
2497	nodeStack.push(mRoot);
2498
2499	int mask = rand();
2500
2501	while (!nodeStack.empty())
2502	{
2503	BspNode *node = nodeStack.top();
2504	nodeStack.pop();
2505
2506	if (node->IsLeaf())
2507	{
2508	return dynamic_cast<BspLeaf *>(node);
2509	}
2510	else
2511	{
2512	BspInterior interior = dynamic_cast<BspInterior >(node);
2513	BspNode *next;
2514
2515	BspNodeGeometry geom;
2516	// todo: not very efficient: constructs full cell everytime
2517	ConstructGeometry(interior, geom);
2518
2519	const int cf = Polygon3::ClassifyPlane(geom.mPolys,
2520	halfspace,
2521	mEpsilon);
2522
2523	if (cf == Polygon3::BACK_SIDE)
2524	next = interior->GetFront();
2525	else
2526	if (cf == Polygon3::FRONT_SIDE)
2527	next = interior->GetFront();
2528	else
2529	{
2530	// random decision
2531	if (mask & 1)
2532	next = interior->GetBack();
2533	else
2534	next = interior->GetFront();
2535	mask = mask >> 1;
2536	}
2537
2538	nodeStack.push(next);
2539	}
2540	}
2541
2542	return NULL;
2543	}
2544
2545
2546	BspLeaf *BspTree::GetRandomLeaf(const bool onlyUnmailed)
2547	{
2548	stack<BspNode *> nodeStack;
2549
2550	nodeStack.push(mRoot);
2551
2552	int mask = rand();
2553
2554	while (!nodeStack.empty())
2555	{
2556	BspNode *node = nodeStack.top();
2557	nodeStack.pop();
2558
2559	if (node->IsLeaf())
2560	{
2561	if ( (!onlyUnmailed \|\| !node->Mailed()) )
2562	return dynamic_cast<BspLeaf *>(node);
2563	}
2564	else
2565	{
2566	BspInterior interior = dynamic_cast<BspInterior >(node);
2567
2568	// random decision
2569	if (mask & 1)
2570	nodeStack.push(interior->GetBack());
2571	else
2572	nodeStack.push(interior->GetFront());
2573
2574	mask = mask >> 1;
2575	}
2576	}
2577
2578	return NULL;
2579	}
2580
2581
2582	void BspTree::AddToPvs(BspLeaf *leaf,
2583	const BoundedRayContainer &rays,
2584	int &sampleContributions,
2585	int &contributingSamples)
2586	{
2587	sampleContributions = 0;
2588	contributingSamples = 0;
2589
2590	BoundedRayContainer::const_iterator it, it_end = rays.end();
2591
2592	ViewCell *vc = leaf->GetViewCell();
2593
2594	// add contributions from samples to the PVS
2595	for (it = rays.begin(); it != it_end; ++ it)
2596	{
2597	int contribution = 0;
2598	Ray ray = (it)->mRay;
2599	float relContribution;
2600	if (!ray->intersections.empty())
2601	contribution += vc->GetPvs().AddSample(ray->intersections[0].mObject,
2602	1.0f,
2603	relContribution);
2604
2605	if (ray->sourceObject.mObject)
2606	contribution += vc->GetPvs().AddSample(ray->sourceObject.mObject,
2607	1.0f,
2608	relContribution);
2609
2610	if (contribution)
2611	{
2612	sampleContributions += contribution;
2613	++ contributingSamples;
2614	}
2615
2616	//if (ray->mFlags & Ray::STORE_BSP_INTERSECTIONS)
2617	// ray->bspIntersections.push_back(Ray::BspIntersection((*it)->mMinT, this));
2618	}
2619	}
2620
2621
2622	int BspTree::ComputePvsSize(const BoundedRayContainer &rays) const
2623	{
2624	int pvsSize = 0;
2625
2626	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
2627
2628	Intersectable::NewMail();
2629
2630	for (rit = rays.begin(); rit != rays.end(); ++ rit)
2631	{
2632	Ray ray = (rit)->mRay;
2633
2634	if (!ray->intersections.empty())
2635	{
2636	if (!ray->intersections[0].mObject->Mailed())
2637	{
2638	ray->intersections[0].mObject->Mail();
2639	++ pvsSize;
2640	}
2641	}
2642	if (ray->sourceObject.mObject)
2643	{
2644	if (!ray->sourceObject.mObject->Mailed())
2645	{
2646	ray->sourceObject.mObject->Mail();
2647	++ pvsSize;
2648	}
2649	}
2650	}
2651
2652	return pvsSize;
2653	}
2654
2655
2656	float BspTree::GetEpsilon() const
2657	{
2658	return mEpsilon;
2659	}
2660
2661
2662	int BspTree::CollectMergeCandidates(const vector<BspLeaf *> leaves,
2663	vector<MergeCandidate> &candidates)
2664	{
2665	BspLeaf::NewMail();
2666
2667	vector<BspLeaf *>::const_iterator it, it_end = leaves.end();
2668
2669	int numCandidates = 0;
2670
2671	// find merge candidates and push them into queue
2672	for (it = leaves.begin(); it != it_end; ++ it)
2673	{
2674	BspLeaf leaf = it;
2675
2676	// the same leaves must not be part of two merge candidates
2677	leaf->Mail();
2678	vector<BspLeaf *> neighbors;
2679	FindNeighbors(leaf, neighbors, true);
2680
2681	vector<BspLeaf *>::const_iterator nit, nit_end = neighbors.end();
2682
2683	// TODO: test if at least one ray goes from one leaf to the other
2684	for (nit = neighbors.begin(); nit != nit_end; ++ nit)
2685	{
2686	if ((*nit)->GetViewCell() != leaf->GetViewCell())
2687	{
2688	MergeCandidate mc(leaf->GetViewCell(), (*nit)->GetViewCell());
2689	candidates.push_back(mc);
2690
2691	++ numCandidates;
2692	if ((numCandidates % 1000) == 0)
2693	{
2694	cout << "collected " << numCandidates << " merge candidates" << endl;
2695	}
2696	}
2697	}
2698	}
2699
2700	Debug << "merge queue: " << (int)candidates.size() << endl;
2701	Debug << "leaves in queue: " << numCandidates << endl;
2702
2703
2704	return (int)leaves.size();
2705	}
2706
2707
2708	int BspTree::CollectMergeCandidates(const VssRayContainer &rays,
2709	vector<MergeCandidate> &candidates)
2710	{
2711	ViewCell::NewMail();
2712	long startTime = GetTime();
2713
2714	map<BspLeaf , vector<BspLeaf> > neighborMap;
2715	ViewCellContainer::const_iterator iit;
2716
2717	int numLeaves = 0;
2718
2719	BspLeaf::NewMail();
2720
2721	for (int i = 0; i < (int)rays.size(); ++ i)
2722	{
2723	VssRay *ray = rays[i];
2724
2725	// traverse leaves stored in the rays and compare and
2726	// merge consecutive leaves (i.e., the neighbors in the tree)
2727	if (ray->mViewCells.size() < 2)
2728	continue;
2729
2730	iit = ray->mViewCells.begin();
2731	BspViewCell bspVc = dynamic_cast<BspViewCell >(*(iit ++));
2732	BspLeaf *leaf = bspVc->mLeaf;
2733
2734	// traverse intersections
2735	// consecutive leaves are neighbors => add them to queue
2736	for (; iit != ray->mViewCells.end(); ++ iit)
2737	{
2738	// next pair
2739	BspLeaf *prevLeaf = leaf;
2740	bspVc = dynamic_cast<BspViewCell >(iit);
2741	leaf = bspVc->mLeaf;
2742
2743	// view space not valid or same view cell
2744	if (!leaf->TreeValid() \|\| !prevLeaf->TreeValid() \|\|
2745	(leaf->GetViewCell() == prevLeaf->GetViewCell()))
2746	continue;
2747
2748	vector<BspLeaf *> &neighbors = neighborMap[leaf];
2749
2750	bool found = false;
2751
2752	// both leaves inserted in queue already =>
2753	// look if double pair already exists
2754	if (leaf->Mailed() && prevLeaf->Mailed())
2755	{
2756	vector<BspLeaf *>::const_iterator it, it_end = neighbors.end();
2757
2758	for (it = neighbors.begin(); !found && (it != it_end); ++ it)
2759	if (*it == prevLeaf)
2760	found = true; // already in queue
2761	}
2762
2763	if (!found)
2764	{
2765	// this pair is not in map yet
2766	// => insert into the neighbor map and the queue
2767	neighbors.push_back(prevLeaf);
2768	neighborMap[prevLeaf].push_back(leaf);
2769
2770	leaf->Mail();
2771	prevLeaf->Mail();
2772
2773	MergeCandidate mc(leaf->GetViewCell(), prevLeaf->GetViewCell());
2774
2775	candidates.push_back(mc);
2776
2777	if (((int)candidates.size() % 1000) == 0)
2778	{
2779	cout << "collected " << (int)candidates.size() << " merge candidates" << endl;
2780	}
2781	}
2782	}
2783	}
2784
2785	Debug << "neighbormap size: " << (int)neighborMap.size() << endl;
2786	Debug << "merge queue: " << (int)candidates.size() << endl;
2787	Debug << "leaves in queue: " << numLeaves << endl;
2788
2789
2790	//-- collect the leaves which haven't been found by ray casting
2791	#if 0
2792	cout << "finding additional merge candidates using geometry" << endl;
2793	vector<BspLeaf *> leaves;
2794	CollectLeaves(leaves, true);
2795	Debug << "found " << (int)leaves.size() << " new leaves" << endl << endl;
2796	CollectMergeCandidates(leaves, candidates);
2797	#endif
2798
2799	return numLeaves;
2800	}
2801
2802
2803
2804
2805	/***************************************************************/
2806	/* BspNodeGeometry Implementation */
2807	/***************************************************************/
2808
2809
2810	BspNodeGeometry::BspNodeGeometry(const BspNodeGeometry &rhs)
2811	{
2812	mPolys.reserve(rhs.mPolys.size());
2813
2814	PolygonContainer::const_iterator it, it_end = rhs.mPolys.end();
2815	for (it = rhs.mPolys.begin(); it != it_end; ++ it)
2816	{
2817	Polygon3 poly = it;
2818	mPolys.push_back(new Polygon3(*poly));
2819	}
2820	}
2821
2822
2823	BspNodeGeometry::~BspNodeGeometry()
2824	{
2825	CLEAR_CONTAINER(mPolys);
2826	}
2827
2828
2829	float BspNodeGeometry::GetArea() const
2830	{
2831	return Polygon3::GetArea(mPolys);
2832	}
2833
2834
2835	float BspNodeGeometry::GetVolume() const
2836	{
2837	//-- compute volume using tetrahedralization of the geometry
2838	// and adding the volume of the single tetrahedrons
2839	float volume = 0;
2840	const float f = 1.0f / 6.0f;
2841
2842	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2843
2844	// note: can take arbitrary point, e.g., the origin. However,
2845	// we rather take the center of mass to prevents precision errors
2846	const Vector3 center = CenterOfMass();
2847
2848	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2849	{
2850	Polygon3 poly = pit;
2851	const Vector3 v0 = poly->mVertices[0] - center;
2852
2853	for (int i = 1; i < (int)poly->mVertices.size() - 1; ++ i)
2854	{
2855	const Vector3 v1 = poly->mVertices[i] - center;
2856	const Vector3 v2 = poly->mVertices[i + 1] - center;
2857
2858	volume += f * (DotProd(v0, CrossProd(v1, v2)));
2859	}
2860	}
2861
2862	return volume;
2863	}
2864
2865
2866	Vector3 BspNodeGeometry::CenterOfMass() const
2867	{
2868	int n = 0;
2869
2870	Vector3 center(0,0,0);
2871
2872	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2873
2874	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2875	{
2876	Polygon3 poly = pit;
2877
2878	VertexContainer::const_iterator vit, vit_end = poly->mVertices.end();
2879
2880	for(vit = poly->mVertices.begin(); vit != vit_end; ++ vit)
2881	{
2882	center += *vit;
2883	++ n;
2884	}
2885	}
2886
2887	return center / (float)n;
2888	}
2889
2890
2891	void BspNodeGeometry::AddToMesh(Mesh &mesh)
2892	{
2893	PolygonContainer::const_iterator it, it_end = mPolys.end();
2894
2895	for (it = mPolys.begin(); it != mPolys.end(); ++ it)
2896	{
2897	(*it)->AddToMesh(mesh);
2898	}
2899	}
2900
2901
2902	void BspNodeGeometry::SplitGeometry(BspNodeGeometry &front,
2903	BspNodeGeometry &back,
2904	const Plane3 &splitPlane,
2905	const AxisAlignedBox3 &box,
2906	const float epsilon) const
2907	{
2908	// get cross section of new polygon
2909	Polygon3 *planePoly = box.CrossSection(splitPlane);
2910
2911	// split polygon with all other polygons
2912	planePoly = SplitPolygon(planePoly, epsilon);
2913
2914	//-- new polygon splits all other polygons
2915	for (int i = 0; i < (int)mPolys.size(); ++ i)
2916	{
2917	/// don't use epsilon here to get exact split planes
2918	const int cf =
2919	mPolys[i]->ClassifyPlane(splitPlane, Limits::Small);
2920
2921	switch (cf)
2922	{
2923	case Polygon3::SPLIT:
2924	{
2925	Polygon3 *poly = new Polygon3(mPolys[i]->mVertices);
2926
2927	Polygon3 *frontPoly = new Polygon3();
2928	Polygon3 *backPoly = new Polygon3();
2929
2930	poly->Split(splitPlane,
2931	*frontPoly,
2932	*backPoly,
2933	epsilon);
2934
2935	DEL_PTR(poly);
2936
2937	if (frontPoly->Valid(epsilon))
2938	front.mPolys.push_back(frontPoly);
2939	else
2940	DEL_PTR(frontPoly);
2941
2942	if (backPoly->Valid(epsilon))
2943	back.mPolys.push_back(backPoly);
2944	else
2945	DEL_PTR(backPoly);
2946	}
2947
2948	break;
2949	case Polygon3::BACK_SIDE:
2950	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2951	break;
2952	case Polygon3::FRONT_SIDE:
2953	front.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2954	break;
2955	case Polygon3::COINCIDENT:
2956	//front.mPolys.push_back(CreateReversePolygon(mPolys[i]));
2957	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2958	break;
2959	default:
2960	break;
2961	}
2962	}
2963
2964	//-- finally add the new polygon to the child node geometries
2965	if (planePoly)
2966	{
2967	// add polygon with normal pointing into positive half space to back cell
2968	back.mPolys.push_back(planePoly);
2969	// add polygon with reverse orientation to front cell
2970	front.mPolys.push_back(planePoly->CreateReversePolygon());
2971	}
2972	}
2973
2974
2975	Polygon3 BspNodeGeometry::SplitPolygon(Polygon3 planePoly,
2976	const float epsilon) const
2977	{
2978	if (!planePoly->Valid(epsilon))
2979	DEL_PTR(planePoly);
2980
2981	// polygon is split by all other planes
2982	for (int i = 0; (i < (int)mPolys.size()) && planePoly; ++ i)
2983	{
2984	Plane3 plane = mPolys[i]->GetSupportingPlane();
2985
2986	/// don't use epsilon here to get exact split planes
2987	const int cf =
2988	planePoly->ClassifyPlane(plane, Limits::Small);
2989
2990	// split new polygon with all previous planes
2991	switch (cf)
2992	{
2993	case Polygon3::SPLIT:
2994	{
2995	Polygon3 *frontPoly = new Polygon3();
2996	Polygon3 *backPoly = new Polygon3();
2997
2998	planePoly->Split(plane,
2999	*frontPoly,
3000	*backPoly,
3001	epsilon);
3002
3003	// don't need anymore
3004	DEL_PTR(planePoly);
3005	DEL_PTR(frontPoly);
3006
3007	// back polygon is belonging to geometry
3008	if (backPoly->Valid(epsilon))
3009	planePoly = backPoly;
3010	else
3011	DEL_PTR(backPoly);
3012	}
3013	break;
3014	case Polygon3::FRONT_SIDE:
3015	DEL_PTR(planePoly);
3016	break;
3017	// polygon is taken as it is
3018	case Polygon3::BACK_SIDE:
3019	case Polygon3::COINCIDENT:
3020	default:
3021	break;
3022	}
3023	}
3024
3025	return planePoly;
3026	}
3027
3028
3029	ViewCell *
3030	BspTree::GetViewCell(const Vector3 &point)
3031	{
3032	if (mRoot == NULL)
3033	return NULL;
3034
3035
3036	stack<BspNode *> nodeStack;
3037	nodeStack.push(mRoot);
3038
3039	ViewCell *viewcell = NULL;
3040
3041	while (!nodeStack.empty()) {
3042	BspNode *node = nodeStack.top();
3043	nodeStack.pop();
3044
3045	if (node->IsLeaf()) {
3046	viewcell = dynamic_cast<BspLeaf *>(node)->mViewCell;
3047	break;
3048	} else {
3049
3050	BspInterior interior = dynamic_cast<BspInterior >(node);
3051
3052	// random decision
3053	if (interior->GetPlane().Side(point) < 0)
3054	nodeStack.push(interior->GetBack());
3055	else
3056	nodeStack.push(interior->GetFront());
3057	}
3058	}
3059
3060	return viewcell;
3061	}
3062
3063
3064	void BspNodeGeometry::IncludeInBox(AxisAlignedBox3 &box)
3065	{
3066	Polygon3::IncludeInBox(mPolys, box);
3067	}
3068
3069
3070	bool BspTree::Export(ofstream &stream)
3071	{
3072	ExportNode(mRoot, stream);
3073
3074	return true;
3075	}
3076
3077
3078	void BspTree::ExportNode(BspNode *node, ofstream &stream)
3079	{
3080	if (node->IsLeaf())
3081	{
3082	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
3083
3084	int id = -1;
3085	if (leaf->GetViewCell() != mOutOfBoundsCell)
3086	id = leaf->GetViewCell()->GetId();
3087
3088	stream << "<Leaf viewCellId=\"" << id << "\" />" << endl;
3089	}
3090	else
3091	{
3092	BspInterior interior = dynamic_cast<BspInterior >(node);
3093
3094	Plane3 plane = interior->GetPlane();
3095	stream << "<Interior plane=\"" << plane.mNormal.x << " "
3096	<< plane.mNormal.y << " " << plane.mNormal.z << " "
3097	<< plane.mD << "\">" << endl;
3098
3099	ExportNode(interior->GetBack(), stream);
3100	ExportNode(interior->GetFront(), stream);
3101
3102	stream << "</Interior>" << endl;
3103	}
3104	}

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source: GTP/trunk/Lib/Vis/Preprocessing/src/ViewCellBsp.cpp @ 611

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