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

Bullet Collision Detection & Physics Library

btWheelInfo.cpp
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1 /*
2 * Copyright (c) 2005 Erwin Coumans http://continuousphysics.com/Bullet/
3 *
4 * Permission to use, copy, modify, distribute and sell this software
5 * and its documentation for any purpose is hereby granted without fee,
6 * provided that the above copyright notice appear in all copies.
7 * Erwin Coumans makes no representations about the suitability
8 * of this software for any purpose.
9 * It is provided "as is" without express or implied warranty.
10 */
11 #include "btWheelInfo.h"
12 #include "BulletDynamics/Dynamics/btRigidBody.h" // for pointvelocity
13
14
15 btScalar btWheelInfo::getSuspensionRestLength() const
16 {
17
18 return m_suspensionRestLength1;
19
20 }
21
22 void btWheelInfo::updateWheel(const btRigidBody& chassis,RaycastInfo& raycastInfo)
23 {
24 (void)raycastInfo;
25
26
27 if (m_raycastInfo.m_isInContact)
28
29 {
30 btScalar project= m_raycastInfo.m_contactNormalWS.dot( m_raycastInfo.m_wheelDirectionWS );
31 btVector3 chassis_velocity_at_contactPoint;
32 btVector3 relpos = m_raycastInfo.m_contactPointWS - chassis.getCenterOfMassPosition();
33 chassis_velocity_at_contactPoint = chassis.getVelocityInLocalPoint( relpos );
34 btScalar projVel = m_raycastInfo.m_contactNormalWS.dot( chassis_velocity_at_contactPoint );
35 if ( project >= btScalar(-0.1))
36 {
37 m_suspensionRelativeVelocity = btScalar(0.0);
38 m_clippedInvContactDotSuspension = btScalar(1.0) / btScalar(0.1);
39 }
40 else
41 {
42 btScalar inv = btScalar(-1.) / project;
43 m_suspensionRelativeVelocity = projVel * inv;
44 m_clippedInvContactDotSuspension = inv;
45 }
46
47 }
48
49 else // Not in contact : position wheel in a nice (rest length) position
50 {
51 m_raycastInfo.m_suspensionLength = this->getSuspensionRestLength();
52 m_suspensionRelativeVelocity = btScalar(0.0);
53 m_raycastInfo.m_contactNormalWS = -m_raycastInfo.m_wheelDirectionWS;
54 m_clippedInvContactDotSuspension = btScalar(1.0);
55 }
56 }
btWheelInfo::RaycastInfo::m_wheelDirectionWS
btVector3 m_wheelDirectionWS
Definition: btWheelInfo.h:47
btWheelInfo::m_suspensionRelativeVelocity
btScalar m_suspensionRelativeVelocity
Definition: btWheelInfo.h:113
btWheelInfo::RaycastInfo
Definition: btWheelInfo.h:40
btWheelInfo::RaycastInfo::m_isInContact
bool m_isInContact
Definition: btWheelInfo.h:49
btRigidBody.h
btVector3::dot
btScalar dot(const btVector3 &v) const
Return the dot product.
Definition: btVector3.h:235
btRigidBody
The btRigidBody is the main class for rigid body objects.
Definition: btRigidBody.h:62
btVector3
btVector3 can be used to represent 3D points and vectors.
Definition: btVector3.h:83
btRigidBody::getVelocityInLocalPoint
btVector3 getVelocityInLocalPoint(const btVector3 &rel_pos) const
Definition: btRigidBody.h:382
btRigidBody::getCenterOfMassPosition
const btVector3 & getCenterOfMassPosition() const
Definition: btRigidBody.h:354
btWheelInfo::m_raycastInfo
RaycastInfo m_raycastInfo
Definition: btWheelInfo.h:53
btWheelInfo::m_clippedInvContactDotSuspension
btScalar m_clippedInvContactDotSuspension
Definition: btWheelInfo.h:112
btWheelInfo::updateWheel
void updateWheel(const btRigidBody &chassis, RaycastInfo &raycastInfo)
Definition: btWheelInfo.cpp:22
btWheelInfo::m_suspensionRestLength1
btScalar m_suspensionRestLength1
Definition: btWheelInfo.h:60
btWheelInfo::RaycastInfo::m_contactNormalWS
btVector3 m_contactNormalWS
Definition: btWheelInfo.h:43
btWheelInfo::getSuspensionRestLength
btScalar getSuspensionRestLength() const
Definition: btWheelInfo.cpp:15
btWheelInfo.h
btWheelInfo::RaycastInfo::m_contactPointWS
btVector3 m_contactPointWS
Definition: btWheelInfo.h:44
btScalar
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition: btScalar.h:292
btWheelInfo::RaycastInfo::m_suspensionLength
btScalar m_suspensionLength
Definition: btWheelInfo.h:45