Bullet Collision Detection & Physics Library
btConvexPlaneCollisionAlgorithm.cpp
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1/*
2Bullet Continuous Collision Detection and Physics Library
3Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/
4
5This software is provided 'as-is', without any express or implied warranty.
6In no event will the authors be held liable for any damages arising from the use of this software.
7Permission is granted to anyone to use this software for any purpose,
8including commercial applications, and to alter it and redistribute it freely,
9subject to the following restrictions:
10
111. 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.
122. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
133. This notice may not be removed or altered from any source distribution.
14*/
15
17
23
24//#include <stdio.h>
25
26btConvexPlaneCollisionAlgorithm::btConvexPlaneCollisionAlgorithm(btPersistentManifold* mf,const btCollisionAlgorithmConstructionInfo& ci,const btCollisionObjectWrapper* col0Wrap,const btCollisionObjectWrapper* col1Wrap, bool isSwapped, int numPerturbationIterations,int minimumPointsPerturbationThreshold)
28m_ownManifold(false),
29m_manifoldPtr(mf),
30m_isSwapped(isSwapped),
31m_numPerturbationIterations(numPerturbationIterations),
32m_minimumPointsPerturbationThreshold(minimumPointsPerturbationThreshold)
33{
34 const btCollisionObjectWrapper* convexObjWrap = m_isSwapped? col1Wrap : col0Wrap;
35 const btCollisionObjectWrapper* planeObjWrap = m_isSwapped? col0Wrap : col1Wrap;
36
37 if (!m_manifoldPtr && m_dispatcher->needsCollision(convexObjWrap->getCollisionObject(),planeObjWrap->getCollisionObject()))
38 {
40 m_ownManifold = true;
41 }
42}
43
44
46{
47 if (m_ownManifold)
48 {
49 if (m_manifoldPtr)
51 }
52}
53
55{
56 const btCollisionObjectWrapper* convexObjWrap = m_isSwapped? body1Wrap : body0Wrap;
57 const btCollisionObjectWrapper* planeObjWrap = m_isSwapped? body0Wrap: body1Wrap;
58
59 btConvexShape* convexShape = (btConvexShape*) convexObjWrap->getCollisionShape();
60 btStaticPlaneShape* planeShape = (btStaticPlaneShape*) planeObjWrap->getCollisionShape();
61
62 bool hasCollision = false;
63 const btVector3& planeNormal = planeShape->getPlaneNormal();
64 const btScalar& planeConstant = planeShape->getPlaneConstant();
65
66 btTransform convexWorldTransform = convexObjWrap->getWorldTransform();
67 btTransform convexInPlaneTrans;
68 convexInPlaneTrans= planeObjWrap->getWorldTransform().inverse() * convexWorldTransform;
69 //now perturbe the convex-world transform
70 convexWorldTransform.getBasis()*=btMatrix3x3(perturbeRot);
71 btTransform planeInConvex;
72 planeInConvex= convexWorldTransform.inverse() * planeObjWrap->getWorldTransform();
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 = planeObjWrap->getWorldTransform() * vtxInPlaneProjected;
81
82 hasCollision = distance < m_manifoldPtr->getContactBreakingThreshold();
84 if (hasCollision)
85 {
87 btVector3 normalOnSurfaceB = planeObjWrap->getWorldTransform().getBasis() * planeNormal;
88 btVector3 pOnB = vtxInPlaneWorld;
89 resultOut->addContactPoint(normalOnSurfaceB,pOnB,distance);
90 }
91}
92
93
95{
96 (void)dispatchInfo;
97 if (!m_manifoldPtr)
98 return;
99
100 const btCollisionObjectWrapper* convexObjWrap = m_isSwapped? body1Wrap : body0Wrap;
101 const btCollisionObjectWrapper* planeObjWrap = m_isSwapped? body0Wrap: body1Wrap;
102
103 btConvexShape* convexShape = (btConvexShape*) convexObjWrap->getCollisionShape();
104 btStaticPlaneShape* planeShape = (btStaticPlaneShape*) planeObjWrap->getCollisionShape();
105
106 bool hasCollision = false;
107 const btVector3& planeNormal = planeShape->getPlaneNormal();
108 const btScalar& planeConstant = planeShape->getPlaneConstant();
109 btTransform planeInConvex;
110 planeInConvex= convexObjWrap->getWorldTransform().inverse() * planeObjWrap->getWorldTransform();
111 btTransform convexInPlaneTrans;
112 convexInPlaneTrans= planeObjWrap->getWorldTransform().inverse() * convexObjWrap->getWorldTransform();
113
114 btVector3 vtx = convexShape->localGetSupportingVertex(planeInConvex.getBasis()*-planeNormal);
115 btVector3 vtxInPlane = convexInPlaneTrans(vtx);
116 btScalar distance = (planeNormal.dot(vtxInPlane) - planeConstant);
117
118 btVector3 vtxInPlaneProjected = vtxInPlane - distance*planeNormal;
119 btVector3 vtxInPlaneWorld = planeObjWrap->getWorldTransform() * vtxInPlaneProjected;
120
121 hasCollision = distance < m_manifoldPtr->getContactBreakingThreshold();
123 if (hasCollision)
124 {
126 btVector3 normalOnSurfaceB = planeObjWrap->getWorldTransform().getBasis() * planeNormal;
127 btVector3 pOnB = vtxInPlaneWorld;
128 resultOut->addContactPoint(normalOnSurfaceB,pOnB,distance);
129 }
130
131 //the perturbation algorithm doesn't work well with implicit surfaces such as spheres, cylinder and cones:
132 //they keep on rolling forever because of the additional off-center contact points
133 //so only enable the feature for polyhedral shapes (btBoxShape, btConvexHullShape etc)
135 {
136 btVector3 v0,v1;
137 btPlaneSpace1(planeNormal,v0,v1);
138 //now perform 'm_numPerturbationIterations' collision queries with the perturbated collision objects
139
140 const btScalar angleLimit = 0.125f * SIMD_PI;
141 btScalar perturbeAngle;
142 btScalar radius = convexShape->getAngularMotionDisc();
143 perturbeAngle = gContactBreakingThreshold / radius;
144 if ( perturbeAngle > angleLimit )
145 perturbeAngle = angleLimit;
146
147 btQuaternion perturbeRot(v0,perturbeAngle);
148 for (int i=0;i<m_numPerturbationIterations;i++)
149 {
151 btQuaternion rotq(planeNormal,iterationAngle);
152 collideSingleContact(rotq.inverse()*perturbeRot*rotq,body0Wrap,body1Wrap,dispatchInfo,resultOut);
153 }
154 }
155
156 if (m_ownManifold)
157 {
159 {
160 resultOut->refreshContactPoints();
161 }
162 }
163}
164
166{
167 (void)resultOut;
168 (void)dispatchInfo;
169 (void)col0;
170 (void)col1;
171
172 //not yet
173 return btScalar(1.);
174}
btScalar gContactBreakingThreshold
#define SIMD_PI
Definition: btScalar.h:504
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition: btScalar.h:292
#define SIMD_2_PI
Definition: btScalar.h:505
void btPlaneSpace1(const T &n, T &p, T &q)
Definition: btVector3.h:1283
btCollisionAlgorithm is an collision interface that is compatible with the Broadphase and btDispatche...
btCollisionObject can be used to manage collision detection objects.
virtual btScalar getAngularMotionDisc() const
getAngularMotionDisc returns the maximum radius needed for Conservative Advancement to handle time-of...
bool isPolyhedral() const
btConvexPlaneCollisionAlgorithm(btPersistentManifold *mf, const btCollisionAlgorithmConstructionInfo &ci, const btCollisionObjectWrapper *body0Wrap, const btCollisionObjectWrapper *body1Wrap, bool isSwapped, int numPerturbationIterations, int minimumPointsPerturbationThreshold)
void collideSingleContact(const btQuaternion &perturbeRot, const btCollisionObjectWrapper *body0Wrap, const btCollisionObjectWrapper *body1Wrap, const btDispatcherInfo &dispatchInfo, btManifoldResult *resultOut)
virtual void processCollision(const btCollisionObjectWrapper *body0Wrap, const btCollisionObjectWrapper *body1Wrap, const btDispatcherInfo &dispatchInfo, btManifoldResult *resultOut)
virtual btScalar calculateTimeOfImpact(btCollisionObject *body0, btCollisionObject *body1, const btDispatcherInfo &dispatchInfo, btManifoldResult *resultOut)
The btConvexShape is an abstract shape interface, implemented by all convex shapes such as btBoxShape...
Definition: btConvexShape.h:32
virtual btVector3 localGetSupportingVertex(const btVector3 &vec) const =0
virtual void releaseManifold(btPersistentManifold *manifold)=0
virtual bool needsCollision(const btCollisionObject *body0, const btCollisionObject *body1)=0
virtual btPersistentManifold * getNewManifold(const btCollisionObject *b0, const btCollisionObject *b1)=0
btManifoldResult is a helper class to manage contact results.
const btPersistentManifold * getPersistentManifold() const
void setPersistentManifold(btPersistentManifold *manifoldPtr)
virtual void addContactPoint(const btVector3 &normalOnBInWorld, const btVector3 &pointInWorld, btScalar depth)
The btMatrix3x3 class implements a 3x3 rotation matrix, to perform linear algebra in combination with...
Definition: btMatrix3x3.h:48
btPersistentManifold is a contact point cache, it stays persistent as long as objects are overlapping...
btScalar getContactBreakingThreshold() const
The btQuaternion implements quaternion to perform linear algebra rotations in combination with btMatr...
Definition: btQuaternion.h:55
The btStaticPlaneShape simulates an infinite non-moving (static) collision plane.
const btScalar & getPlaneConstant() const
const btVector3 & getPlaneNormal() const
The btTransform class supports rigid transforms with only translation and rotation and no scaling/she...
Definition: btTransform.h:34
btTransform inverse() const
Return the inverse of this transform.
Definition: btTransform.h:188
btMatrix3x3 & getBasis()
Return the basis matrix for the rotation.
Definition: btTransform.h:112
btVector3 can be used to represent 3D points and vectors.
Definition: btVector3.h:84
btScalar dot(const btVector3 &v) const
Return the dot product.
Definition: btVector3.h:235
const btCollisionShape * getCollisionShape() const
const btCollisionObject * getCollisionObject() const
const btTransform & getWorldTransform() const