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Diffstat (limited to 'thirdparty/bullet/BulletDynamics/ConstraintSolver/btUniversalConstraint.cpp')
| -rw-r--r-- | thirdparty/bullet/BulletDynamics/ConstraintSolver/btUniversalConstraint.cpp | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/thirdparty/bullet/BulletDynamics/ConstraintSolver/btUniversalConstraint.cpp b/thirdparty/bullet/BulletDynamics/ConstraintSolver/btUniversalConstraint.cpp new file mode 100644 index 0000000000..b009f41aec --- /dev/null +++ b/thirdparty/bullet/BulletDynamics/ConstraintSolver/btUniversalConstraint.cpp @@ -0,0 +1,87 @@ +/* +Bullet Continuous Collision Detection and Physics Library, http://bulletphysics.org +Copyright (C) 2006, 2007 Sony Computer Entertainment Inc. + +This software is provided 'as-is', without any express or implied warranty. +In no event will the authors be held liable for any damages arising from the use of this software. +Permission is granted to anyone to use this software for any purpose, +including commercial applications, and to alter it and redistribute it freely, +subject to the following restrictions: + +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. +2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. +3. This notice may not be removed or altered from any source distribution. +*/ + + + +#include "btUniversalConstraint.h" +#include "BulletDynamics/Dynamics/btRigidBody.h" +#include "LinearMath/btTransformUtil.h" + + + +#define UNIV_EPS btScalar(0.01f) + + +// constructor +// anchor, axis1 and axis2 are in world coordinate system +// axis1 must be orthogonal to axis2 +btUniversalConstraint::btUniversalConstraint(btRigidBody& rbA, btRigidBody& rbB, const btVector3& anchor, const btVector3& axis1, const btVector3& axis2) +: btGeneric6DofConstraint(rbA, rbB, btTransform::getIdentity(), btTransform::getIdentity(), true), + m_anchor(anchor), + m_axis1(axis1), + m_axis2(axis2) +{ + // build frame basis + // 6DOF constraint uses Euler angles and to define limits + // it is assumed that rotational order is : + // Z - first, allowed limits are (-PI,PI); + // new position of Y - second (allowed limits are (-PI/2 + epsilon, PI/2 - epsilon), where epsilon is a small positive number + // used to prevent constraint from instability on poles; + // new position of X, allowed limits are (-PI,PI); + // So to simulate ODE Universal joint we should use parent axis as Z, child axis as Y and limit all other DOFs + // Build the frame in world coordinate system first + btVector3 zAxis = m_axis1.normalize(); + btVector3 yAxis = m_axis2.normalize(); + btVector3 xAxis = yAxis.cross(zAxis); // we want right coordinate system + btTransform frameInW; + frameInW.setIdentity(); + frameInW.getBasis().setValue( xAxis[0], yAxis[0], zAxis[0], + xAxis[1], yAxis[1], zAxis[1], + xAxis[2], yAxis[2], zAxis[2]); + frameInW.setOrigin(anchor); + // now get constraint frame in local coordinate systems + m_frameInA = rbA.getCenterOfMassTransform().inverse() * frameInW; + m_frameInB = rbB.getCenterOfMassTransform().inverse() * frameInW; + // sei limits + setLinearLowerLimit(btVector3(0., 0., 0.)); + setLinearUpperLimit(btVector3(0., 0., 0.)); + setAngularLowerLimit(btVector3(0.f, -SIMD_HALF_PI + UNIV_EPS, -SIMD_PI + UNIV_EPS)); + setAngularUpperLimit(btVector3(0.f, SIMD_HALF_PI - UNIV_EPS, SIMD_PI - UNIV_EPS)); +} + +void btUniversalConstraint::setAxis(const btVector3& axis1,const btVector3& axis2) +{ + m_axis1 = axis1; + m_axis2 = axis2; + + btVector3 zAxis = axis1.normalized(); + btVector3 yAxis = axis2.normalized(); + btVector3 xAxis = yAxis.cross(zAxis); // we want right coordinate system + + btTransform frameInW; + frameInW.setIdentity(); + frameInW.getBasis().setValue( xAxis[0], yAxis[0], zAxis[0], + xAxis[1], yAxis[1], zAxis[1], + xAxis[2], yAxis[2], zAxis[2]); + frameInW.setOrigin(m_anchor); + + // now get constraint frame in local coordinate systems + m_frameInA = m_rbA.getCenterOfMassTransform().inverse() * frameInW; + m_frameInB = m_rbB.getCenterOfMassTransform().inverse() * frameInW; + + calculateTransforms(); +} + + |