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source: trunk/VUT/GtpVisibilityPreprocessor/src/ViewCellBsp.cpp @ 490

Revision 490, 66.3 KB checked in by mattausch, 19 years ago (diff)
added loading and storing rays capability

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

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