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
17 #include "btContinuousConvexCollision.h"
18 #include "BulletCollision/CollisionShapes/btConvexShape.h"
19 #include "BulletCollision/NarrowPhaseCollision/btSimplexSolverInterface.h"
20 #include "LinearMath/btTransformUtil.h"
21 #include "BulletCollision/CollisionShapes/btSphereShape.h"
22
23 #include "btGjkPairDetector.h"
24 #include "btPointCollector.h"
25 #include "BulletCollision/CollisionShapes/btStaticPlaneShape.h"
26
27
28
btContinuousConvexCollision(const btConvexShape * convexA,const btConvexShape * convexB,btSimplexSolverInterface * simplexSolver,btConvexPenetrationDepthSolver * penetrationDepthSolver)29 btContinuousConvexCollision::btContinuousConvexCollision ( const btConvexShape* convexA,const btConvexShape* convexB,btSimplexSolverInterface* simplexSolver, btConvexPenetrationDepthSolver* penetrationDepthSolver)
30 :m_simplexSolver(simplexSolver),
31 m_penetrationDepthSolver(penetrationDepthSolver),
32 m_convexA(convexA),m_convexB1(convexB),m_planeShape(0)
33 {
34 }
35
36
btContinuousConvexCollision(const btConvexShape * convexA,const btStaticPlaneShape * plane)37 btContinuousConvexCollision::btContinuousConvexCollision( const btConvexShape* convexA,const btStaticPlaneShape* plane)
38 :m_simplexSolver(0),
39 m_penetrationDepthSolver(0),
40 m_convexA(convexA),m_convexB1(0),m_planeShape(plane)
41 {
42 }
43
44
45 /// This maximum should not be necessary. It allows for untested/degenerate cases in production code.
46 /// You don't want your game ever to lock-up.
47 #define MAX_ITERATIONS 64
48
computeClosestPoints(const btTransform & transA,const btTransform & transB,btPointCollector & pointCollector)49 void btContinuousConvexCollision::computeClosestPoints( const btTransform& transA, const btTransform& transB,btPointCollector& pointCollector)
50 {
51 if (m_convexB1)
52 {
53 m_simplexSolver->reset();
54 btGjkPairDetector gjk(m_convexA,m_convexB1,m_convexA->getShapeType(),m_convexB1->getShapeType(),m_convexA->getMargin(),m_convexB1->getMargin(),m_simplexSolver,m_penetrationDepthSolver);
55 btGjkPairDetector::ClosestPointInput input;
56 input.m_transformA = transA;
57 input.m_transformB = transB;
58 gjk.getClosestPoints(input,pointCollector,0);
59 } else
60 {
61 //convex versus plane
62 const btConvexShape* convexShape = m_convexA;
63 const btStaticPlaneShape* planeShape = m_planeShape;
64
65 const btVector3& planeNormal = planeShape->getPlaneNormal();
66 const btScalar& planeConstant = planeShape->getPlaneConstant();
67
68 btTransform convexWorldTransform = transA;
69 btTransform convexInPlaneTrans;
70 convexInPlaneTrans= transB.inverse() * convexWorldTransform;
71 btTransform planeInConvex;
72 planeInConvex= convexWorldTransform.inverse() * transB;
73
74 btVector3 vtx = convexShape->localGetSupportingVertex(planeInConvex.getBasis()*-planeNormal);
75
76 btVector3 vtxInPlane = convexInPlaneTrans(vtx);
77 btScalar distance = (planeNormal.dot(vtxInPlane) - planeConstant);
78
79 btVector3 vtxInPlaneProjected = vtxInPlane - distance*planeNormal;
80 btVector3 vtxInPlaneWorld = transB * vtxInPlaneProjected;
81 btVector3 normalOnSurfaceB = transB.getBasis() * planeNormal;
82
83 pointCollector.addContactPoint(
84 normalOnSurfaceB,
85 vtxInPlaneWorld,
86 distance);
87 }
88 }
89
calcTimeOfImpact(const btTransform & fromA,const btTransform & toA,const btTransform & fromB,const btTransform & toB,CastResult & result)90 bool btContinuousConvexCollision::calcTimeOfImpact(
91 const btTransform& fromA,
92 const btTransform& toA,
93 const btTransform& fromB,
94 const btTransform& toB,
95 CastResult& result)
96 {
97
98
99 /// compute linear and angular velocity for this interval, to interpolate
100 btVector3 linVelA,angVelA,linVelB,angVelB;
101 btTransformUtil::calculateVelocity(fromA,toA,btScalar(1.),linVelA,angVelA);
102 btTransformUtil::calculateVelocity(fromB,toB,btScalar(1.),linVelB,angVelB);
103
104
105 btScalar boundingRadiusA = m_convexA->getAngularMotionDisc();
106 btScalar boundingRadiusB = m_convexB1?m_convexB1->getAngularMotionDisc():0.f;
107
108 btScalar maxAngularProjectedVelocity = angVelA.length() * boundingRadiusA + angVelB.length() * boundingRadiusB;
109 btVector3 relLinVel = (linVelB-linVelA);
110
111 btScalar relLinVelocLength = (linVelB-linVelA).length();
112
113 if ((relLinVelocLength+maxAngularProjectedVelocity) == 0.f)
114 return false;
115
116
117
118 btScalar lambda = btScalar(0.);
119 btVector3 v(1,0,0);
120
121 int maxIter = MAX_ITERATIONS;
122
123 btVector3 n;
124 n.setValue(btScalar(0.),btScalar(0.),btScalar(0.));
125 bool hasResult = false;
126 btVector3 c;
127
128 btScalar lastLambda = lambda;
129 //btScalar epsilon = btScalar(0.001);
130
131 int numIter = 0;
132 //first solution, using GJK
133
134
135 btScalar radius = 0.001f;
136 // result.drawCoordSystem(sphereTr);
137
138 btPointCollector pointCollector1;
139
140 {
141
142 computeClosestPoints(fromA,fromB,pointCollector1);
143
144 hasResult = pointCollector1.m_hasResult;
145 c = pointCollector1.m_pointInWorld;
146 }
147
148 if (hasResult)
149 {
150 btScalar dist;
151 dist = pointCollector1.m_distance + result.m_allowedPenetration;
152 n = pointCollector1.m_normalOnBInWorld;
153 btScalar projectedLinearVelocity = relLinVel.dot(n);
154 if ((projectedLinearVelocity+ maxAngularProjectedVelocity)<=SIMD_EPSILON)
155 return false;
156
157 //not close enough
158 while (dist > radius)
159 {
160 if (result.m_debugDrawer)
161 {
162 result.m_debugDrawer->drawSphere(c,0.2f,btVector3(1,1,1));
163 }
164 btScalar dLambda = btScalar(0.);
165
166 projectedLinearVelocity = relLinVel.dot(n);
167
168
169 //don't report time of impact for motion away from the contact normal (or causes minor penetration)
170 if ((projectedLinearVelocity+ maxAngularProjectedVelocity)<=SIMD_EPSILON)
171 return false;
172
173 dLambda = dist / (projectedLinearVelocity+ maxAngularProjectedVelocity);
174
175
176
177 lambda = lambda + dLambda;
178
179 if (lambda > btScalar(1.))
180 return false;
181
182 if (lambda < btScalar(0.))
183 return false;
184
185
186 //todo: next check with relative epsilon
187 if (lambda <= lastLambda)
188 {
189 return false;
190 //n.setValue(0,0,0);
191 break;
192 }
193 lastLambda = lambda;
194
195
196
197 //interpolate to next lambda
198 btTransform interpolatedTransA,interpolatedTransB,relativeTrans;
199
200 btTransformUtil::integrateTransform(fromA,linVelA,angVelA,lambda,interpolatedTransA);
201 btTransformUtil::integrateTransform(fromB,linVelB,angVelB,lambda,interpolatedTransB);
202 relativeTrans = interpolatedTransB.inverseTimes(interpolatedTransA);
203
204 if (result.m_debugDrawer)
205 {
206 result.m_debugDrawer->drawSphere(interpolatedTransA.getOrigin(),0.2f,btVector3(1,0,0));
207 }
208
209 result.DebugDraw( lambda );
210
211 btPointCollector pointCollector;
212 computeClosestPoints(interpolatedTransA,interpolatedTransB,pointCollector);
213
214 if (pointCollector.m_hasResult)
215 {
216 dist = pointCollector.m_distance+result.m_allowedPenetration;
217 c = pointCollector.m_pointInWorld;
218 n = pointCollector.m_normalOnBInWorld;
219 } else
220 {
221 result.reportFailure(-1, numIter);
222 return false;
223 }
224
225 numIter++;
226 if (numIter > maxIter)
227 {
228 result.reportFailure(-2, numIter);
229 return false;
230 }
231 }
232
233 result.m_fraction = lambda;
234 result.m_normal = n;
235 result.m_hitPoint = c;
236 return true;
237 }
238
239 return false;
240
241 }
242
243