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

Bullet Collision Detection & Physics Library

btHinge2Constraint.cpp
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1 /*
2 Bullet Continuous Collision Detection and Physics Library, http://bulletphysics.org
3 Copyright (C) 2006, 2007 Sony Computer Entertainment Inc.
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
17
18 #include "btHinge2Constraint.h"
19 #include "BulletDynamics/Dynamics/btRigidBody.h"
20 #include "LinearMath/btTransformUtil.h"
21
22
23
24 // constructor
25 // anchor, axis1 and axis2 are in world coordinate system
26 // axis1 must be orthogonal to axis2
27 btHinge2Constraint::btHinge2Constraint(btRigidBody& rbA, btRigidBody& rbB, btVector3& anchor, btVector3& axis1, btVector3& axis2)
28 : btGeneric6DofSpring2Constraint(rbA, rbB, btTransform::getIdentity(), btTransform::getIdentity(),RO_XYZ),
29 m_anchor(anchor),
30 m_axis1(axis1),
31 m_axis2(axis2)
32 {
33 // build frame basis
34 // 6DOF constraint uses Euler angles and to define limits
35 // it is assumed that rotational order is :
36 // Z - first, allowed limits are (-PI,PI);
37 // new position of Y - second (allowed limits are (-PI/2 + epsilon, PI/2 - epsilon), where epsilon is a small positive number
38 // used to prevent constraint from instability on poles;
39 // new position of X, allowed limits are (-PI,PI);
40 // So to simulate ODE Universal joint we should use parent axis as Z, child axis as Y and limit all other DOFs
41 // Build the frame in world coordinate system first
42 btVector3 zAxis = axis1.normalize();
43 btVector3 xAxis = axis2.normalize();
44 btVector3 yAxis = zAxis.cross(xAxis); // we want right coordinate system
45 btTransform frameInW;
46 frameInW.setIdentity();
47 frameInW.getBasis().setValue( xAxis[0], yAxis[0], zAxis[0],
48 xAxis[1], yAxis[1], zAxis[1],
49 xAxis[2], yAxis[2], zAxis[2]);
50 frameInW.setOrigin(anchor);
51 // now get constraint frame in local coordinate systems
52 m_frameInA = rbA.getCenterOfMassTransform().inverse() * frameInW;
53 m_frameInB = rbB.getCenterOfMassTransform().inverse() * frameInW;
54 // sei limits
55 setLinearLowerLimit(btVector3(0.f, 0.f, -1.f));
56 setLinearUpperLimit(btVector3(0.f, 0.f, 1.f));
57 // like front wheels of a car
58 setAngularLowerLimit(btVector3(1.f, 0.f, -SIMD_HALF_PI * 0.5f));
59 setAngularUpperLimit(btVector3(-1.f, 0.f, SIMD_HALF_PI * 0.5f));
60 // enable suspension
61 enableSpring(2, true);
62 setStiffness(2, SIMD_PI * SIMD_PI * 4.f);
63 setDamping(2, 0.01f);
64 setEquilibriumPoint();
65 }
66
btTransform::setOrigin
void setOrigin(const btVector3 &origin)
Set the translational element.
Definition: btTransform.h:150
btTransformUtil.h
btRigidBody::getCenterOfMassTransform
const btTransform & getCenterOfMassTransform() const
Definition: btRigidBody.h:359
btTransform::setIdentity
void setIdentity()
Set this transformation to the identity.
Definition: btTransform.h:172
btHinge2Constraint.h
btRigidBody.h
SIMD_HALF_PI
#define SIMD_HALF_PI
Definition: btScalar.h:479
btGeneric6DofSpring2Constraint
Definition: btGeneric6DofSpring2Constraint.h:277
btVector3::normalize
btVector3 & normalize()
Normalize this vector x^2 + y^2 + z^2 = 1.
Definition: btVector3.h:307
btGeneric6DofSpring2Constraint::m_frameInA
btTransform m_frameInA
Definition: btGeneric6DofSpring2Constraint.h:281
SIMD_PI
#define SIMD_PI
Definition: btScalar.h:477
btVector3::cross
btVector3 cross(const btVector3 &v) const
Return the cross product between this and another vector.
Definition: btVector3.h:387
btTransform::getBasis
btMatrix3x3 & getBasis()
Return the basis matrix for the rotation.
Definition: btTransform.h:112
btMatrix3x3::setValue
void setValue(const btScalar &xx, const btScalar &xy, const btScalar &xz, const btScalar &yx, const btScalar &yy, const btScalar &yz, const btScalar &zx, const btScalar &zy, const btScalar &zz)
Set the values of the matrix explicitly (row major)
Definition: btMatrix3x3.h:198
btRigidBody
The btRigidBody is the main class for rigid body objects.
Definition: btRigidBody.h:62
btGeneric6DofSpring2Constraint::setEquilibriumPoint
void setEquilibriumPoint()
Definition: btGeneric6DofSpring2Constraint.cpp:1052
btGeneric6DofSpring2Constraint::setLinearUpperLimit
void setLinearUpperLimit(const btVector3 &linearUpper)
Definition: btGeneric6DofSpring2Constraint.h:366
btGeneric6DofSpring2Constraint::setLinearLowerLimit
void setLinearLowerLimit(const btVector3 &linearLower)
Definition: btGeneric6DofSpring2Constraint.h:364
btGeneric6DofSpring2Constraint::setAngularLowerLimit
void setAngularLowerLimit(const btVector3 &angularLower)
Definition: btGeneric6DofSpring2Constraint.h:369
btVector3
btVector3 can be used to represent 3D points and vectors.
Definition: btVector3.h:83
btHinge2Constraint::btHinge2Constraint
btHinge2Constraint(btRigidBody &rbA, btRigidBody &rbB, btVector3 &anchor, btVector3 &axis1, btVector3 &axis2)
Definition: btHinge2Constraint.cpp:27
btTransform
The btTransform class supports rigid transforms with only translation and rotation and no scaling/she...
Definition: btTransform.h:34
btGeneric6DofSpring2Constraint::setStiffness
void setStiffness(int index, btScalar stiffness, bool limitIfNeeded=true)
Definition: btGeneric6DofSpring2Constraint.cpp:1028
btGeneric6DofSpring2Constraint::enableSpring
void enableSpring(int index, bool onOff)
Definition: btGeneric6DofSpring2Constraint.cpp:1019
btGeneric6DofSpring2Constraint::setAngularUpperLimit
void setAngularUpperLimit(const btVector3 &angularUpper)
Definition: btGeneric6DofSpring2Constraint.h:393
btGeneric6DofSpring2Constraint::m_frameInB
btTransform m_frameInB
Definition: btGeneric6DofSpring2Constraint.h:282
btGeneric6DofSpring2Constraint::setDamping
void setDamping(int index, btScalar damping, bool limitIfNeeded=true)
Definition: btGeneric6DofSpring2Constraint.cpp:1040
btTransform::inverse
btTransform inverse() const
Return the inverse of this transform.
Definition: btTransform.h:188
RO_XYZ
Definition: btGeneric6DofSpring2Constraint.h:61