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 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 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 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 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
