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1 /*
2 Bullet Continuous Collision Detection and Physics Library
3 Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/
4 
5 This software is provided 'as-is', without any express or implied warranty.
6 In no event will the authors be held liable for any damages arising from the use of this software.
7 Permission is granted to anyone to use this software for any purpose,
8 including commercial applications, and to alter it and redistribute it freely,
9 subject to the following restrictions:
10 
11 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
12 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
13 3. This notice may not be removed or altered from any source distribution.
14 */
15 
16 #include "btMinkowskiPenetrationDepthSolver.h"
17 #include "BulletCollision/NarrowPhaseCollision/btSubSimplexConvexCast.h"
18 #include "BulletCollision/NarrowPhaseCollision/btVoronoiSimplexSolver.h"
19 #include "BulletCollision/NarrowPhaseCollision/btGjkPairDetector.h"
20 #include "BulletCollision/CollisionShapes/btConvexShape.h"
21 
22 #define NUM_UNITSPHERE_POINTS 42
23 
24 
calcPenDepth(btSimplexSolverInterface & simplexSolver,const btConvexShape * convexA,const btConvexShape * convexB,const btTransform & transA,const btTransform & transB,btVector3 & v,btVector3 & pa,btVector3 & pb,class btIDebugDraw * debugDraw)25 bool btMinkowskiPenetrationDepthSolver::calcPenDepth(btSimplexSolverInterface& simplexSolver,
26 												   const btConvexShape* convexA,const btConvexShape* convexB,
27 												   const btTransform& transA,const btTransform& transB,
28 												   btVector3& v, btVector3& pa, btVector3& pb,
29 												   class btIDebugDraw* debugDraw
30 												   )
31 {
32 
33 	(void)v;
34 
35 	bool check2d= convexA->isConvex2d() && convexB->isConvex2d();
36 
37 	struct btIntermediateResult : public btDiscreteCollisionDetectorInterface::Result
38 	{
39 
40 		btIntermediateResult():m_hasResult(false)
41 		{
42 		}
43 
44 		btVector3 m_normalOnBInWorld;
45 		btVector3 m_pointInWorld;
46 		btScalar m_depth;
47 		bool	m_hasResult;
48 
49 		virtual void setShapeIdentifiersA(int partId0,int index0)
50 		{
51 			(void)partId0;
52 			(void)index0;
53 		}
54 		virtual void setShapeIdentifiersB(int partId1,int index1)
55 		{
56 			(void)partId1;
57 			(void)index1;
58 		}
59 		void addContactPoint(const btVector3& normalOnBInWorld,const btVector3& pointInWorld,btScalar depth)
60 		{
61 			m_normalOnBInWorld = normalOnBInWorld;
62 			m_pointInWorld = pointInWorld;
63 			m_depth = depth;
64 			m_hasResult = true;
65 		}
66 	};
67 
68 	//just take fixed number of orientation, and sample the penetration depth in that direction
69 	btScalar minProj = btScalar(BT_LARGE_FLOAT);
70 	btVector3 minNorm(btScalar(0.), btScalar(0.), btScalar(0.));
71 	btVector3 minA,minB;
72 	btVector3 seperatingAxisInA,seperatingAxisInB;
73 	btVector3 pInA,qInB,pWorld,qWorld,w;
74 
75 #ifndef __SPU__
76 #define USE_BATCHED_SUPPORT 1
77 #endif
78 #ifdef USE_BATCHED_SUPPORT
79 
80 	btVector3	supportVerticesABatch[NUM_UNITSPHERE_POINTS+MAX_PREFERRED_PENETRATION_DIRECTIONS*2];
81 	btVector3	supportVerticesBBatch[NUM_UNITSPHERE_POINTS+MAX_PREFERRED_PENETRATION_DIRECTIONS*2];
82 	btVector3	seperatingAxisInABatch[NUM_UNITSPHERE_POINTS+MAX_PREFERRED_PENETRATION_DIRECTIONS*2];
83 	btVector3	seperatingAxisInBBatch[NUM_UNITSPHERE_POINTS+MAX_PREFERRED_PENETRATION_DIRECTIONS*2];
84 	int i;
85 
86 	int numSampleDirections = NUM_UNITSPHERE_POINTS;
87 
88 	for (i=0;i<numSampleDirections;i++)
89 	{
90 		btVector3 norm = getPenetrationDirections()[i];
91 		seperatingAxisInABatch[i] =  (-norm) * transA.getBasis() ;
92 		seperatingAxisInBBatch[i] =  norm   * transB.getBasis() ;
93 	}
94 
95 	{
96 		int numPDA = convexA->getNumPreferredPenetrationDirections();
97 		if (numPDA)
98 		{
99 			for (int i=0;i<numPDA;i++)
100 			{
101 				btVector3 norm;
102 				convexA->getPreferredPenetrationDirection(i,norm);
103 				norm  = transA.getBasis() * norm;
104 				getPenetrationDirections()[numSampleDirections] = norm;
105 				seperatingAxisInABatch[numSampleDirections] = (-norm) * transA.getBasis();
106 				seperatingAxisInBBatch[numSampleDirections] = norm * transB.getBasis();
107 				numSampleDirections++;
108 			}
109 		}
110 	}
111 
112 	{
113 		int numPDB = convexB->getNumPreferredPenetrationDirections();
114 		if (numPDB)
115 		{
116 			for (int i=0;i<numPDB;i++)
117 			{
118 				btVector3 norm;
119 				convexB->getPreferredPenetrationDirection(i,norm);
120 				norm  = transB.getBasis() * norm;
121 				getPenetrationDirections()[numSampleDirections] = norm;
122 				seperatingAxisInABatch[numSampleDirections] = (-norm) * transA.getBasis();
123 				seperatingAxisInBBatch[numSampleDirections] = norm * transB.getBasis();
124 				numSampleDirections++;
125 			}
126 		}
127 	}
128 
129 
130 
131 
132 	convexA->batchedUnitVectorGetSupportingVertexWithoutMargin(seperatingAxisInABatch,supportVerticesABatch,numSampleDirections);
133 	convexB->batchedUnitVectorGetSupportingVertexWithoutMargin(seperatingAxisInBBatch,supportVerticesBBatch,numSampleDirections);
134 
135 	for (i=0;i<numSampleDirections;i++)
136 	{
137 		btVector3 norm = getPenetrationDirections()[i];
138 		if (check2d)
139 		{
140 			norm[2] = 0.f;
141 		}
142 		if (norm.length2()>0.01)
143 		{
144 
145 			seperatingAxisInA = seperatingAxisInABatch[i];
146 			seperatingAxisInB = seperatingAxisInBBatch[i];
147 
148 			pInA = supportVerticesABatch[i];
149 			qInB = supportVerticesBBatch[i];
150 
151 			pWorld = transA(pInA);
152 			qWorld = transB(qInB);
153 			if (check2d)
154 			{
155 				pWorld[2] = 0.f;
156 				qWorld[2] = 0.f;
157 			}
158 
159 			w	= qWorld - pWorld;
160 			btScalar delta = norm.dot(w);
161 			//find smallest delta
162 			if (delta < minProj)
163 			{
164 				minProj = delta;
165 				minNorm = norm;
166 				minA = pWorld;
167 				minB = qWorld;
168 			}
169 		}
170 	}
171 #else
172 
173 	int numSampleDirections = NUM_UNITSPHERE_POINTS;
174 
175 #ifndef __SPU__
176 	{
177 		int numPDA = convexA->getNumPreferredPenetrationDirections();
178 		if (numPDA)
179 		{
180 			for (int i=0;i<numPDA;i++)
181 			{
182 				btVector3 norm;
183 				convexA->getPreferredPenetrationDirection(i,norm);
184 				norm  = transA.getBasis() * norm;
185 				getPenetrationDirections()[numSampleDirections] = norm;
186 				numSampleDirections++;
187 			}
188 		}
189 	}
190 
191 	{
192 		int numPDB = convexB->getNumPreferredPenetrationDirections();
193 		if (numPDB)
194 		{
195 			for (int i=0;i<numPDB;i++)
196 			{
197 				btVector3 norm;
198 				convexB->getPreferredPenetrationDirection(i,norm);
199 				norm  = transB.getBasis() * norm;
200 				getPenetrationDirections()[numSampleDirections] = norm;
201 				numSampleDirections++;
202 			}
203 		}
204 	}
205 #endif // __SPU__
206 
207 	for (int i=0;i<numSampleDirections;i++)
208 	{
209 		const btVector3& norm = getPenetrationDirections()[i];
210 		seperatingAxisInA = (-norm)* transA.getBasis();
211 		seperatingAxisInB = norm* transB.getBasis();
212 		pInA = convexA->localGetSupportVertexWithoutMarginNonVirtual(seperatingAxisInA);
213 		qInB = convexB->localGetSupportVertexWithoutMarginNonVirtual(seperatingAxisInB);
214 		pWorld = transA(pInA);
215 		qWorld = transB(qInB);
216 		w	= qWorld - pWorld;
217 		btScalar delta = norm.dot(w);
218 		//find smallest delta
219 		if (delta < minProj)
220 		{
221 			minProj = delta;
222 			minNorm = norm;
223 			minA = pWorld;
224 			minB = qWorld;
225 		}
226 	}
227 #endif //USE_BATCHED_SUPPORT
228 
229 	//add the margins
230 
231 	minA += minNorm*convexA->getMarginNonVirtual();
232 	minB -= minNorm*convexB->getMarginNonVirtual();
233 	//no penetration
234 	if (minProj < btScalar(0.))
235 		return false;
236 
237 	btScalar extraSeparation = 0.5f;///scale dependent
238 	minProj += extraSeparation+(convexA->getMarginNonVirtual() + convexB->getMarginNonVirtual());
239 
240 
241 
242 
243 
244 //#define DEBUG_DRAW 1
245 #ifdef DEBUG_DRAW
246 	if (debugDraw)
247 	{
248 		btVector3 color(0,1,0);
249 		debugDraw->drawLine(minA,minB,color);
250 		color = btVector3 (1,1,1);
251 		btVector3 vec = minB-minA;
252 		btScalar prj2 = minNorm.dot(vec);
253 		debugDraw->drawLine(minA,minA+(minNorm*minProj),color);
254 
255 	}
256 #endif //DEBUG_DRAW
257 
258 
259 
260 	btGjkPairDetector gjkdet(convexA,convexB,&simplexSolver,0);
261 
262 	btScalar offsetDist = minProj;
263 	btVector3 offset = minNorm * offsetDist;
264 
265 
266 
267 	btGjkPairDetector::ClosestPointInput input;
268 
269 	btVector3 newOrg = transA.getOrigin() + offset;
270 
271 	btTransform displacedTrans = transA;
272 	displacedTrans.setOrigin(newOrg);
273 
274 	input.m_transformA = displacedTrans;
275 	input.m_transformB = transB;
276 	input.m_maximumDistanceSquared = btScalar(BT_LARGE_FLOAT);//minProj;
277 
278 	btIntermediateResult res;
279 	gjkdet.setCachedSeperatingAxis(-minNorm);
280 	gjkdet.getClosestPoints(input,res,debugDraw);
281 
282 	btScalar correctedMinNorm = minProj - res.m_depth;
283 
284 
285 	//the penetration depth is over-estimated, relax it
286 	btScalar penetration_relaxation= btScalar(1.);
287 	minNorm*=penetration_relaxation;
288 
289 
290 	if (res.m_hasResult)
291 	{
292 
293 		pa = res.m_pointInWorld - minNorm * correctedMinNorm;
294 		pb = res.m_pointInWorld;
295 		v = minNorm;
296 
297 #ifdef DEBUG_DRAW
298 		if (debugDraw)
299 		{
300 			btVector3 color(1,0,0);
301 			debugDraw->drawLine(pa,pb,color);
302 		}
303 #endif//DEBUG_DRAW
304 
305 
306 	}
307 	return res.m_hasResult;
308 }
309 
getPenetrationDirections()310 btVector3*	btMinkowskiPenetrationDepthSolver::getPenetrationDirections()
311 {
312 	static btVector3	sPenetrationDirections[NUM_UNITSPHERE_POINTS+MAX_PREFERRED_PENETRATION_DIRECTIONS*2] =
313 	{
314 	btVector3(btScalar(0.000000) , btScalar(-0.000000),btScalar(-1.000000)),
315 	btVector3(btScalar(0.723608) , btScalar(-0.525725),btScalar(-0.447219)),
316 	btVector3(btScalar(-0.276388) , btScalar(-0.850649),btScalar(-0.447219)),
317 	btVector3(btScalar(-0.894426) , btScalar(-0.000000),btScalar(-0.447216)),
318 	btVector3(btScalar(-0.276388) , btScalar(0.850649),btScalar(-0.447220)),
319 	btVector3(btScalar(0.723608) , btScalar(0.525725),btScalar(-0.447219)),
320 	btVector3(btScalar(0.276388) , btScalar(-0.850649),btScalar(0.447220)),
321 	btVector3(btScalar(-0.723608) , btScalar(-0.525725),btScalar(0.447219)),
322 	btVector3(btScalar(-0.723608) , btScalar(0.525725),btScalar(0.447219)),
323 	btVector3(btScalar(0.276388) , btScalar(0.850649),btScalar(0.447219)),
324 	btVector3(btScalar(0.894426) , btScalar(0.000000),btScalar(0.447216)),
325 	btVector3(btScalar(-0.000000) , btScalar(0.000000),btScalar(1.000000)),
326 	btVector3(btScalar(0.425323) , btScalar(-0.309011),btScalar(-0.850654)),
327 	btVector3(btScalar(-0.162456) , btScalar(-0.499995),btScalar(-0.850654)),
328 	btVector3(btScalar(0.262869) , btScalar(-0.809012),btScalar(-0.525738)),
329 	btVector3(btScalar(0.425323) , btScalar(0.309011),btScalar(-0.850654)),
330 	btVector3(btScalar(0.850648) , btScalar(-0.000000),btScalar(-0.525736)),
331 	btVector3(btScalar(-0.525730) , btScalar(-0.000000),btScalar(-0.850652)),
332 	btVector3(btScalar(-0.688190) , btScalar(-0.499997),btScalar(-0.525736)),
333 	btVector3(btScalar(-0.162456) , btScalar(0.499995),btScalar(-0.850654)),
334 	btVector3(btScalar(-0.688190) , btScalar(0.499997),btScalar(-0.525736)),
335 	btVector3(btScalar(0.262869) , btScalar(0.809012),btScalar(-0.525738)),
336 	btVector3(btScalar(0.951058) , btScalar(0.309013),btScalar(0.000000)),
337 	btVector3(btScalar(0.951058) , btScalar(-0.309013),btScalar(0.000000)),
338 	btVector3(btScalar(0.587786) , btScalar(-0.809017),btScalar(0.000000)),
339 	btVector3(btScalar(0.000000) , btScalar(-1.000000),btScalar(0.000000)),
340 	btVector3(btScalar(-0.587786) , btScalar(-0.809017),btScalar(0.000000)),
341 	btVector3(btScalar(-0.951058) , btScalar(-0.309013),btScalar(-0.000000)),
342 	btVector3(btScalar(-0.951058) , btScalar(0.309013),btScalar(-0.000000)),
343 	btVector3(btScalar(-0.587786) , btScalar(0.809017),btScalar(-0.000000)),
344 	btVector3(btScalar(-0.000000) , btScalar(1.000000),btScalar(-0.000000)),
345 	btVector3(btScalar(0.587786) , btScalar(0.809017),btScalar(-0.000000)),
346 	btVector3(btScalar(0.688190) , btScalar(-0.499997),btScalar(0.525736)),
347 	btVector3(btScalar(-0.262869) , btScalar(-0.809012),btScalar(0.525738)),
348 	btVector3(btScalar(-0.850648) , btScalar(0.000000),btScalar(0.525736)),
349 	btVector3(btScalar(-0.262869) , btScalar(0.809012),btScalar(0.525738)),
350 	btVector3(btScalar(0.688190) , btScalar(0.499997),btScalar(0.525736)),
351 	btVector3(btScalar(0.525730) , btScalar(0.000000),btScalar(0.850652)),
352 	btVector3(btScalar(0.162456) , btScalar(-0.499995),btScalar(0.850654)),
353 	btVector3(btScalar(-0.425323) , btScalar(-0.309011),btScalar(0.850654)),
354 	btVector3(btScalar(-0.425323) , btScalar(0.309011),btScalar(0.850654)),
355 	btVector3(btScalar(0.162456) , btScalar(0.499995),btScalar(0.850654))
356 	};
357 
358 	return sPenetrationDirections;
359 }
360 
361 
362