Context Navigation

source: trunk/VUT/GtpVisibilityPreprocessor/src/ViewCellBsp.cpp @ 544

Revision 544, 68.7 KB checked in by mattausch, 18 years ago (diff)

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

Note: See TracBrowser for help on using the repository browser.

Download in other formats: