Bullet Collision Detection & Physics Library: btHinge2Constraint.cpp Source File

Bullet Collision Detection & Physics Library

btHinge2Constraint.cpp
Go to the documentation of this file.
1/*
2Bullet Continuous Collision Detection and Physics Library, http://bulletphysics.org
3Copyright (C) 2006, 2007 Sony Computer Entertainment Inc.
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
16#include "btHinge2Constraint.h"
17#include "BulletDynamics/Dynamics/btRigidBody.h"
18#include "LinearMath/btTransformUtil.h"
19
20// constructor
21// anchor, axis1 and axis2 are in world coordinate system
22// axis1 must be orthogonal to axis2
23btHinge2Constraint::btHinge2Constraint(btRigidBody& rbA, btRigidBody& rbB, btVector3& anchor, btVector3& axis1, btVector3& axis2)
24 : btGeneric6DofSpring2Constraint(rbA, rbB, btTransform::getIdentity(), btTransform::getIdentity(), RO_XYZ),
25 m_anchor(anchor),
26 m_axis1(axis1),
27 m_axis2(axis2)
28{
29 // build frame basis
30 // 6DOF constraint uses Euler angles and to define limits
31 // it is assumed that rotational order is :
32 // Z - first, allowed limits are (-PI,PI);
33 // new position of Y - second (allowed limits are (-PI/2 + epsilon, PI/2 - epsilon), where epsilon is a small positive number
34 // used to prevent constraint from instability on poles;
35 // new position of X, allowed limits are (-PI,PI);
36 // So to simulate ODE Universal joint we should use parent axis as Z, child axis as Y and limit all other DOFs
37 // Build the frame in world coordinate system first
38 btVector3 zAxis = axis1.normalize();
39 btVector3 xAxis = axis2.normalize();
40 btVector3 yAxis = zAxis.cross(xAxis); // we want right coordinate system
41 btTransform frameInW;
42 frameInW.setIdentity();
43 frameInW.getBasis().setValue(xAxis[0], yAxis[0], zAxis[0],
44 xAxis[1], yAxis[1], zAxis[1],
45 xAxis[2], yAxis[2], zAxis[2]);
46 frameInW.setOrigin(anchor);
47 // now get constraint frame in local coordinate systems
48 m_frameInA = rbA.getCenterOfMassTransform().inverse() * frameInW;
49 m_frameInB = rbB.getCenterOfMassTransform().inverse() * frameInW;
50 // sei limits
51 setLinearLowerLimit(btVector3(0.f, 0.f, -1.f));
52 setLinearUpperLimit(btVector3(0.f, 0.f, 1.f));
53 // like front wheels of a car
54 setAngularLowerLimit(btVector3(1.f, 0.f, -SIMD_HALF_PI * 0.5f));
55 setAngularUpperLimit(btVector3(-1.f, 0.f, SIMD_HALF_PI * 0.5f));
56 // enable suspension
57 enableSpring(2, true);
58 setStiffness(2, SIMD_PI * SIMD_PI * 4.f);
59 setDamping(2, 0.01f);
60 setEquilibriumPoint();
61}
RO_XYZ
@ RO_XYZ
Definition btGeneric6DofSpring2Constraint.h:59
btHinge2Constraint.h
inverse
btQuaternion inverse(const btQuaternion &q)
Return the inverse of a quaternion.
Definition btQuaternion.h:909
btRigidBody.h
SIMD_PI
#define SIMD_PI
Definition btScalar.h:526
SIMD_HALF_PI
#define SIMD_HALF_PI
Definition btScalar.h:528
btTransformUtil.h
btGeneric6DofSpring2Constraint::setStiffness
void setStiffness(int index, btScalar stiffness, bool limitIfNeeded=true)
Definition btGeneric6DofSpring2Constraint.cpp:1139
btGeneric6DofSpring2Constraint::m_frameInB
btTransform m_frameInB
Definition btGeneric6DofSpring2Constraint.h:277
btGeneric6DofSpring2Constraint::setDamping
void setDamping(int index, btScalar damping, bool limitIfNeeded=true)
Definition btGeneric6DofSpring2Constraint.cpp:1154
btGeneric6DofSpring2Constraint::m_frameInA
btTransform m_frameInA
Definition btGeneric6DofSpring2Constraint.h:276
btGeneric6DofSpring2Constraint::setLinearUpperLimit
void setLinearUpperLimit(const btVector3 &linearUpper)
Definition btGeneric6DofSpring2Constraint.h:359
btGeneric6DofSpring2Constraint::enableSpring
void enableSpring(int index, bool onOff)
Definition btGeneric6DofSpring2Constraint.cpp:1130
btGeneric6DofSpring2Constraint::setAngularUpperLimit
void setAngularUpperLimit(const btVector3 &angularUpper)
Definition btGeneric6DofSpring2Constraint.h:386
btGeneric6DofSpring2Constraint::setAngularLowerLimit
void setAngularLowerLimit(const btVector3 &angularLower)
Definition btGeneric6DofSpring2Constraint.h:362
btGeneric6DofSpring2Constraint::setLinearLowerLimit
void setLinearLowerLimit(const btVector3 &linearLower)
Definition btGeneric6DofSpring2Constraint.h:357
btGeneric6DofSpring2Constraint::setEquilibriumPoint
void setEquilibriumPoint()
Definition btGeneric6DofSpring2Constraint.cpp:1169
btGeneric6DofSpring2Constraint::btGeneric6DofSpring2Constraint
btGeneric6DofSpring2Constraint(btRigidBody &rbA, btRigidBody &rbB, const btTransform &frameInA, const btTransform &frameInB, RotateOrder rotOrder=RO_XYZ)
2009 March: btGeneric6DofConstraint refactored by Roman Ponomarev Added support for generic constrain...
Definition btGeneric6DofSpring2Constraint.cpp:46
btHinge2Constraint::m_anchor
btVector3 m_anchor
Definition btHinge2Constraint.h:32
btHinge2Constraint::m_axis2
btVector3 m_axis2
Definition btHinge2Constraint.h:34
btHinge2Constraint::btHinge2Constraint
btHinge2Constraint(btRigidBody &rbA, btRigidBody &rbB, btVector3 &anchor, btVector3 &axis1, btVector3 &axis2)
Definition btHinge2Constraint.cpp:23
btHinge2Constraint::m_axis1
btVector3 m_axis1
Definition btHinge2Constraint.h:33
btRigidBody
The btRigidBody is the main class for rigid body objects.
Definition btRigidBody.h:60
btRigidBody::getCenterOfMassTransform
const btTransform & getCenterOfMassTransform() const
Definition btRigidBody.h:429
btTransform
The btTransform class supports rigid transforms with only translation and rotation and no scaling/she...
Definition btTransform.h:30
btTransform::getBasis
btMatrix3x3 & getBasis()
Return the basis matrix for the rotation.
Definition btTransform.h:109
btTransform::setIdentity
void setIdentity()
Set this transformation to the identity.
Definition btTransform.h:167
btTransform::setOrigin
void setOrigin(const btVector3 &origin)
Set the translational element.
Definition btTransform.h:147
btVector3
btVector3 can be used to represent 3D points and vectors.
Definition btVector3.h:82
btVector3::cross
btVector3 cross(const btVector3 &v) const
Return the cross product between this and another vector.
Definition btVector3.h:380
btVector3::normalize
btVector3 & normalize()
Normalize this vector x^2 + y^2 + z^2 = 1.
Definition btVector3.h:303