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Diffstat (limited to 'thirdparty/bullet/BulletCollision/NarrowPhaseCollision/btComputeGjkEpaPenetration.h')
| -rw-r--r-- | thirdparty/bullet/BulletCollision/NarrowPhaseCollision/btComputeGjkEpaPenetration.h | 369 |
1 files changed, 369 insertions, 0 deletions
diff --git a/thirdparty/bullet/BulletCollision/NarrowPhaseCollision/btComputeGjkEpaPenetration.h b/thirdparty/bullet/BulletCollision/NarrowPhaseCollision/btComputeGjkEpaPenetration.h new file mode 100644 index 0000000000..9eb880b8df --- /dev/null +++ b/thirdparty/bullet/BulletCollision/NarrowPhaseCollision/btComputeGjkEpaPenetration.h @@ -0,0 +1,369 @@ +/* +Bullet Continuous Collision Detection and Physics Library +Copyright (c) 2003-2014 Erwin Coumans http://bulletphysics.org + +This software is provided 'as-is', without any express or implied warranty. +In no event will the authors be held liable for any damages arising from the use of this software. +Permission is granted to anyone to use this software for any purpose, +including commercial applications, and to alter it and redistribute it freely, +subject to the following restrictions: + +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. +2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. +3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef BT_GJK_EPA_PENETATION_CONVEX_COLLISION_H +#define BT_GJK_EPA_PENETATION_CONVEX_COLLISION_H + +#include "LinearMath/btTransform.h" // Note that btVector3 might be double precision... +#include "btGjkEpa3.h" +#include "btGjkCollisionDescription.h" +#include "BulletCollision/NarrowPhaseCollision/btVoronoiSimplexSolver.h" + + + + + + +template <typename btConvexTemplate> +bool btGjkEpaCalcPenDepth(const btConvexTemplate& a, const btConvexTemplate& b, + const btGjkCollisionDescription& colDesc, + btVector3& v, btVector3& wWitnessOnA, btVector3& wWitnessOnB) +{ + (void)v; + + // const btScalar radialmargin(btScalar(0.)); + + btVector3 guessVector(b.getWorldTransform().getOrigin()-a.getWorldTransform().getOrigin());//?? why not use the GJK input? + + btGjkEpaSolver3::sResults results; + + + if(btGjkEpaSolver3_Penetration(a,b,guessVector,results)) + + { + // debugDraw->drawLine(results.witnesses[1],results.witnesses[1]+results.normal,btVector3(255,0,0)); + //resultOut->addContactPoint(results.normal,results.witnesses[1],-results.depth); + wWitnessOnA = results.witnesses[0]; + wWitnessOnB = results.witnesses[1]; + v = results.normal; + return true; + } else + { + if(btGjkEpaSolver3_Distance(a,b,guessVector,results)) + { + wWitnessOnA = results.witnesses[0]; + wWitnessOnB = results.witnesses[1]; + v = results.normal; + return false; + } + } + return false; +} + +template <typename btConvexTemplate, typename btGjkDistanceTemplate> +int btComputeGjkEpaPenetration(const btConvexTemplate& a, const btConvexTemplate& b, const btGjkCollisionDescription& colDesc, btVoronoiSimplexSolver& simplexSolver, btGjkDistanceTemplate* distInfo) +{ + + bool m_catchDegeneracies = true; + btScalar m_cachedSeparatingDistance = 0.f; + + btScalar distance=btScalar(0.); + btVector3 normalInB(btScalar(0.),btScalar(0.),btScalar(0.)); + + btVector3 pointOnA,pointOnB; + btTransform localTransA = a.getWorldTransform(); + btTransform localTransB = b.getWorldTransform(); + + btScalar marginA = a.getMargin(); + btScalar marginB = b.getMargin(); + + int m_curIter = 0; + int gGjkMaxIter = colDesc.m_maxGjkIterations;//this is to catch invalid input, perhaps check for #NaN? + btVector3 m_cachedSeparatingAxis = colDesc.m_firstDir; + + bool isValid = false; + bool checkSimplex = false; + bool checkPenetration = true; + int m_degenerateSimplex = 0; + + int m_lastUsedMethod = -1; + + { + btScalar squaredDistance = BT_LARGE_FLOAT; + btScalar delta = btScalar(0.); + + btScalar margin = marginA + marginB; + + + + simplexSolver.reset(); + + for ( ; ; ) + //while (true) + { + + btVector3 seperatingAxisInA = (-m_cachedSeparatingAxis)* localTransA.getBasis(); + btVector3 seperatingAxisInB = m_cachedSeparatingAxis* localTransB.getBasis(); + + btVector3 pInA = a.getLocalSupportWithoutMargin(seperatingAxisInA); + btVector3 qInB = b.getLocalSupportWithoutMargin(seperatingAxisInB); + + btVector3 pWorld = localTransA(pInA); + btVector3 qWorld = localTransB(qInB); + + + + btVector3 w = pWorld - qWorld; + delta = m_cachedSeparatingAxis.dot(w); + + // potential exit, they don't overlap + if ((delta > btScalar(0.0)) && (delta * delta > squaredDistance * colDesc.m_maximumDistanceSquared)) + { + m_degenerateSimplex = 10; + checkSimplex=true; + //checkPenetration = false; + break; + } + + //exit 0: the new point is already in the simplex, or we didn't come any closer + if (simplexSolver.inSimplex(w)) + { + m_degenerateSimplex = 1; + checkSimplex = true; + break; + } + // are we getting any closer ? + btScalar f0 = squaredDistance - delta; + btScalar f1 = squaredDistance * colDesc.m_gjkRelError2; + + if (f0 <= f1) + { + if (f0 <= btScalar(0.)) + { + m_degenerateSimplex = 2; + } else + { + m_degenerateSimplex = 11; + } + checkSimplex = true; + break; + } + + //add current vertex to simplex + simplexSolver.addVertex(w, pWorld, qWorld); + btVector3 newCachedSeparatingAxis; + + //calculate the closest point to the origin (update vector v) + if (!simplexSolver.closest(newCachedSeparatingAxis)) + { + m_degenerateSimplex = 3; + checkSimplex = true; + break; + } + + if(newCachedSeparatingAxis.length2()<colDesc.m_gjkRelError2) + { + m_cachedSeparatingAxis = newCachedSeparatingAxis; + m_degenerateSimplex = 6; + checkSimplex = true; + break; + } + + btScalar previousSquaredDistance = squaredDistance; + squaredDistance = newCachedSeparatingAxis.length2(); +#if 0 + ///warning: this termination condition leads to some problems in 2d test case see Bullet/Demos/Box2dDemo + if (squaredDistance>previousSquaredDistance) + { + m_degenerateSimplex = 7; + squaredDistance = previousSquaredDistance; + checkSimplex = false; + break; + } +#endif // + + + //redundant m_simplexSolver->compute_points(pointOnA, pointOnB); + + //are we getting any closer ? + if (previousSquaredDistance - squaredDistance <= SIMD_EPSILON * previousSquaredDistance) + { + // m_simplexSolver->backup_closest(m_cachedSeparatingAxis); + checkSimplex = true; + m_degenerateSimplex = 12; + + break; + } + + m_cachedSeparatingAxis = newCachedSeparatingAxis; + + //degeneracy, this is typically due to invalid/uninitialized worldtransforms for a btCollisionObject + if (m_curIter++ > gGjkMaxIter) + { +#if defined(DEBUG) || defined (_DEBUG) + + printf("btGjkPairDetector maxIter exceeded:%i\n",m_curIter); + printf("sepAxis=(%f,%f,%f), squaredDistance = %f\n", + m_cachedSeparatingAxis.getX(), + m_cachedSeparatingAxis.getY(), + m_cachedSeparatingAxis.getZ(), + squaredDistance); +#endif + + break; + + } + + + bool check = (!simplexSolver.fullSimplex()); + //bool check = (!m_simplexSolver->fullSimplex() && squaredDistance > SIMD_EPSILON * m_simplexSolver->maxVertex()); + + if (!check) + { + //do we need this backup_closest here ? + // m_simplexSolver->backup_closest(m_cachedSeparatingAxis); + m_degenerateSimplex = 13; + break; + } + } + + if (checkSimplex) + { + simplexSolver.compute_points(pointOnA, pointOnB); + normalInB = m_cachedSeparatingAxis; + + btScalar lenSqr =m_cachedSeparatingAxis.length2(); + + //valid normal + if (lenSqr < 0.0001) + { + m_degenerateSimplex = 5; + } + if (lenSqr > SIMD_EPSILON*SIMD_EPSILON) + { + btScalar rlen = btScalar(1.) / btSqrt(lenSqr ); + normalInB *= rlen; //normalize + + btScalar s = btSqrt(squaredDistance); + + btAssert(s > btScalar(0.0)); + pointOnA -= m_cachedSeparatingAxis * (marginA / s); + pointOnB += m_cachedSeparatingAxis * (marginB / s); + distance = ((btScalar(1.)/rlen) - margin); + isValid = true; + + m_lastUsedMethod = 1; + } else + { + m_lastUsedMethod = 2; + } + } + + bool catchDegeneratePenetrationCase = + (m_catchDegeneracies && m_degenerateSimplex && ((distance+margin) < 0.01)); + + //if (checkPenetration && !isValid) + if (checkPenetration && (!isValid || catchDegeneratePenetrationCase )) + { + //penetration case + + //if there is no way to handle penetrations, bail out + + // Penetration depth case. + btVector3 tmpPointOnA,tmpPointOnB; + + m_cachedSeparatingAxis.setZero(); + + bool isValid2 = btGjkEpaCalcPenDepth(a,b, + colDesc, + m_cachedSeparatingAxis, tmpPointOnA, tmpPointOnB); + + if (isValid2) + { + btVector3 tmpNormalInB = tmpPointOnB-tmpPointOnA; + btScalar lenSqr = tmpNormalInB.length2(); + if (lenSqr <= (SIMD_EPSILON*SIMD_EPSILON)) + { + tmpNormalInB = m_cachedSeparatingAxis; + lenSqr = m_cachedSeparatingAxis.length2(); + } + + if (lenSqr > (SIMD_EPSILON*SIMD_EPSILON)) + { + tmpNormalInB /= btSqrt(lenSqr); + btScalar distance2 = -(tmpPointOnA-tmpPointOnB).length(); + //only replace valid penetrations when the result is deeper (check) + if (!isValid || (distance2 < distance)) + { + distance = distance2; + pointOnA = tmpPointOnA; + pointOnB = tmpPointOnB; + normalInB = tmpNormalInB; + + isValid = true; + m_lastUsedMethod = 3; + } else + { + m_lastUsedMethod = 8; + } + } else + { + m_lastUsedMethod = 9; + } + } else + + { + ///this is another degenerate case, where the initial GJK calculation reports a degenerate case + ///EPA reports no penetration, and the second GJK (using the supporting vector without margin) + ///reports a valid positive distance. Use the results of the second GJK instead of failing. + ///thanks to Jacob.Langford for the reproduction case + ///http://code.google.com/p/bullet/issues/detail?id=250 + + + if (m_cachedSeparatingAxis.length2() > btScalar(0.)) + { + btScalar distance2 = (tmpPointOnA-tmpPointOnB).length()-margin; + //only replace valid distances when the distance is less + if (!isValid || (distance2 < distance)) + { + distance = distance2; + pointOnA = tmpPointOnA; + pointOnB = tmpPointOnB; + pointOnA -= m_cachedSeparatingAxis * marginA ; + pointOnB += m_cachedSeparatingAxis * marginB ; + normalInB = m_cachedSeparatingAxis; + normalInB.normalize(); + + isValid = true; + m_lastUsedMethod = 6; + } else + { + m_lastUsedMethod = 5; + } + } + } + } + } + + + + if (isValid && ((distance < 0) || (distance*distance < colDesc.m_maximumDistanceSquared))) + { + + m_cachedSeparatingAxis = normalInB; + m_cachedSeparatingDistance = distance; + distInfo->m_distance = distance; + distInfo->m_normalBtoA = normalInB; + distInfo->m_pointOnB = pointOnB; + distInfo->m_pointOnA = pointOnB+normalInB*distance; + return 0; + } + return -m_lastUsedMethod; +} + + + + +#endif //BT_GJK_EPA_PENETATION_CONVEX_COLLISION_H |