Bullet Collision Detection & Physics Library: btConvexPlaneCollisionAlgorithm.cpp Source File

Bullet Collision Detection & Physics Library

btConvexPlaneCollisionAlgorithm.cpp
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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 "btConvexPlaneCollisionAlgorithm.h"
17
18 #include "BulletCollision/CollisionDispatch/btCollisionDispatcher.h"
19 #include "BulletCollision/CollisionDispatch/btCollisionObject.h"
20 #include "BulletCollision/CollisionShapes/btConvexShape.h"
21 #include "BulletCollision/CollisionShapes/btStaticPlaneShape.h"
22 #include "BulletCollision/CollisionDispatch/btCollisionObjectWrapper.h"
23
24 //#include <stdio.h>
25
26 btConvexPlaneCollisionAlgorithm::btConvexPlaneCollisionAlgorithm(btPersistentManifold* mf,const btCollisionAlgorithmConstructionInfo& ci,const btCollisionObjectWrapper* col0Wrap,const btCollisionObjectWrapper* col1Wrap, bool isSwapped, int numPerturbationIterations,int minimumPointsPerturbationThreshold)
27 : btCollisionAlgorithm(ci),
28 m_ownManifold(false),
29 m_manifoldPtr(mf),
30 m_isSwapped(isSwapped),
31 m_numPerturbationIterations(numPerturbationIterations),
32 m_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 {
39 m_manifoldPtr = m_dispatcher->getNewManifold(convexObjWrap->getCollisionObject(),planeObjWrap->getCollisionObject());
40 m_ownManifold = true;
41 }
42 }
43
44
45 btConvexPlaneCollisionAlgorithm::~btConvexPlaneCollisionAlgorithm()
46 {
47 if (m_ownManifold)
48 {
49 if (m_manifoldPtr)
50 m_dispatcher->releaseManifold(m_manifoldPtr);
51 }
52 }
53
54 void btConvexPlaneCollisionAlgorithm::collideSingleContact (const btQuaternion& perturbeRot, const btCollisionObjectWrapper* body0Wrap,const btCollisionObjectWrapper* body1Wrap,const btDispatcherInfo& dispatchInfo,btManifoldResult* resultOut)
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();
83 resultOut->setPersistentManifold(m_manifoldPtr);
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
94 void btConvexPlaneCollisionAlgorithm::processCollision (const btCollisionObjectWrapper* body0Wrap,const btCollisionObjectWrapper* body1Wrap,const btDispatcherInfo& dispatchInfo,btManifoldResult* resultOut)
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();
122 resultOut->setPersistentManifold(m_manifoldPtr);
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)
134 if (convexShape->isPolyhedral() && resultOut->getPersistentManifold()->getNumContacts()<m_minimumPointsPerturbationThreshold)
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 {
150 btScalar iterationAngle = i*(SIMD_2_PI/btScalar(m_numPerturbationIterations));
151 btQuaternion rotq(planeNormal,iterationAngle);
152 collideSingleContact(rotq.inverse()*perturbeRot*rotq,body0Wrap,body1Wrap,dispatchInfo,resultOut);
153 }
154 }
155
156 if (m_ownManifold)
157 {
158 if (m_manifoldPtr->getNumContacts())
159 {
160 resultOut->refreshContactPoints();
161 }
162 }
163 }
164
165 btScalar btConvexPlaneCollisionAlgorithm::calculateTimeOfImpact(btCollisionObject* col0,btCollisionObject* col1,const btDispatcherInfo& dispatchInfo,btManifoldResult* resultOut)
166 {
167 (void)resultOut;
168 (void)dispatchInfo;
169 (void)col0;
170 (void)col1;
171
172 //not yet
173 return btScalar(1.);
174 }
btDispatcher::releaseManifold
virtual void releaseManifold(btPersistentManifold *manifold)=0
btPersistentManifold
btPersistentManifold is a contact point cache, it stays persistent as long as objects are overlapping...
Definition: btPersistentManifold.h:63
btPersistentManifold::getContactBreakingThreshold
btScalar getContactBreakingThreshold() const
Definition: btPersistentManifold.cpp:242
btConvexShape::localGetSupportingVertex
virtual btVector3 localGetSupportingVertex(const btVector3 &vec) const =0
btConvexPlaneCollisionAlgorithm::processCollision
virtual void processCollision(const btCollisionObjectWrapper *body0Wrap, const btCollisionObjectWrapper *body1Wrap, const btDispatcherInfo &dispatchInfo, btManifoldResult *resultOut)
Definition: btConvexPlaneCollisionAlgorithm.cpp:94
btStaticPlaneShape::getPlaneConstant
const btScalar & getPlaneConstant() const
Definition: btStaticPlaneShape.h:55
btManifoldResult::setPersistentManifold
void setPersistentManifold(btPersistentManifold *manifoldPtr)
Definition: btManifoldResult.h:72
btPersistentManifold::getNumContacts
int getNumContacts() const
Definition: btPersistentManifold.h:117
btPlaneSpace1
void btPlaneSpace1(const T &n, T &p, T &q)
Definition: btVector3.h:1283
btStaticPlaneShape.h
btManifoldResult::refreshContactPoints
void refreshContactPoints()
Definition: btManifoldResult.h:101
btConvexPlaneCollisionAlgorithm::~btConvexPlaneCollisionAlgorithm
virtual ~btConvexPlaneCollisionAlgorithm()
Definition: btConvexPlaneCollisionAlgorithm.cpp:45
btManifoldResult
btManifoldResult is a helper class to manage contact results.
Definition: btManifoldResult.h:39
btCollisionObjectWrapper::getCollisionShape
const btCollisionShape * getCollisionShape() const
Definition: btCollisionObjectWrapper.h:40
btConvexPlaneCollisionAlgorithm::m_numPerturbationIterations
int m_numPerturbationIterations
Definition: btConvexPlaneCollisionAlgorithm.h:34
btConvexShape.h
btCollisionAlgorithm::m_dispatcher
btDispatcher * m_dispatcher
Definition: btCollisionAlgorithm.h:60
btConvexPlaneCollisionAlgorithm::calculateTimeOfImpact
virtual btScalar calculateTimeOfImpact(btCollisionObject *body0, btCollisionObject *body1, const btDispatcherInfo &dispatchInfo, btManifoldResult *resultOut)
Definition: btConvexPlaneCollisionAlgorithm.cpp:165
btConvexShape
The btConvexShape is an abstract shape interface, implemented by all convex shapes such as btBoxShape...
Definition: btConvexShape.h:31
btConvexPlaneCollisionAlgorithm::m_manifoldPtr
btPersistentManifold * m_manifoldPtr
Definition: btConvexPlaneCollisionAlgorithm.h:32
btManifoldResult::addContactPoint
virtual void addContactPoint(const btVector3 &normalOnBInWorld, const btVector3 &pointInWorld, btScalar depth)
Definition: btManifoldResult.cpp:104
SIMD_PI
#define SIMD_PI
Definition: btScalar.h:504
SIMD_2_PI
#define SIMD_2_PI
Definition: btScalar.h:505
btConvexPlaneCollisionAlgorithm::m_isSwapped
bool m_isSwapped
Definition: btConvexPlaneCollisionAlgorithm.h:33
btConvexPlaneCollisionAlgorithm.h
btVector3::dot
btScalar dot(const btVector3 &v) const
Return the dot product.
Definition: btVector3.h:235
btCollisionObjectWrapper::getCollisionObject
const btCollisionObject * getCollisionObject() const
Definition: btCollisionObjectWrapper.h:39
btCollisionObject
btCollisionObject can be used to manage collision detection objects.
Definition: btCollisionObject.h:49
btTransform::getBasis
btMatrix3x3 & getBasis()
Return the basis matrix for the rotation.
Definition: btTransform.h:112
btDispatcher::getNewManifold
virtual btPersistentManifold * getNewManifold(const btCollisionObject *b0, const btCollisionObject *b1)=0
btCollisionObjectWrapper.h
btConvexPlaneCollisionAlgorithm::btConvexPlaneCollisionAlgorithm
btConvexPlaneCollisionAlgorithm(btPersistentManifold *mf, const btCollisionAlgorithmConstructionInfo &ci, const btCollisionObjectWrapper *body0Wrap, const btCollisionObjectWrapper *body1Wrap, bool isSwapped, int numPerturbationIterations, int minimumPointsPerturbationThreshold)
Definition: btConvexPlaneCollisionAlgorithm.cpp:26
btVector3
btVector3 can be used to represent 3D points and vectors.
Definition: btVector3.h:83
btConvexPlaneCollisionAlgorithm::collideSingleContact
void collideSingleContact(const btQuaternion &perturbeRot, const btCollisionObjectWrapper *body0Wrap, const btCollisionObjectWrapper *body1Wrap, const btDispatcherInfo &dispatchInfo, btManifoldResult *resultOut)
Definition: btConvexPlaneCollisionAlgorithm.cpp:54
btConvexPlaneCollisionAlgorithm::m_ownManifold
bool m_ownManifold
Definition: btConvexPlaneCollisionAlgorithm.h:31
btCollisionShape::isPolyhedral
bool isPolyhedral() const
Definition: btCollisionShape.h:63
btTransform
The btTransform class supports rigid transforms with only translation and rotation and no scaling/she...
Definition: btTransform.h:34
btStaticPlaneShape::getPlaneNormal
const btVector3 & getPlaneNormal() const
Definition: btStaticPlaneShape.h:50
btCollisionDispatcher.h
btCollisionObjectWrapper::getWorldTransform
const btTransform & getWorldTransform() const
Definition: btCollisionObjectWrapper.h:38
btCollisionObject.h
btConvexPlaneCollisionAlgorithm::m_minimumPointsPerturbationThreshold
int m_minimumPointsPerturbationThreshold
Definition: btConvexPlaneCollisionAlgorithm.h:35
btMatrix3x3
The btMatrix3x3 class implements a 3x3 rotation matrix, to perform linear algebra in combination with...
Definition: btMatrix3x3.h:48
btCollisionShape::getAngularMotionDisc
virtual btScalar getAngularMotionDisc() const
getAngularMotionDisc returns the maximum radius needed for Conservative Advancement to handle time-of...
Definition: btCollisionShape.cpp:50
btQuaternion
The btQuaternion implements quaternion to perform linear algebra rotations in combination with btMatr...
Definition: btQuaternion.h:55
btDispatcherInfo
Definition: btDispatcher.h:30
btStaticPlaneShape
The btStaticPlaneShape simulates an infinite non-moving (static) collision plane. ...
Definition: btStaticPlaneShape.h:23
btDispatcher::needsCollision
virtual bool needsCollision(const btCollisionObject *body0, const btCollisionObject *body1)=0
btCollisionAlgorithmConstructionInfo
Definition: btCollisionAlgorithm.h:32
btCollisionAlgorithm
btCollisionAlgorithm is an collision interface that is compatible with the Broadphase and btDispatche...
Definition: btCollisionAlgorithm.h:55
btManifoldResult::getPersistentManifold
const btPersistentManifold * getPersistentManifold() const
Definition: btManifoldResult.h:77
gContactBreakingThreshold
btScalar gContactBreakingThreshold
Definition: btPersistentManifold.cpp:21
btCollisionObjectWrapper
Definition: btCollisionObjectWrapper.h:17
btTransform::inverse
btTransform inverse() const
Return the inverse of this transform.
Definition: btTransform.h:188
btScalar
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition: btScalar.h:292