mirror of
https://github.com/godotengine/godot.git
synced 2025-11-03 23:21:15 +00:00
67 lines
3 KiB
C++
67 lines
3 KiB
C++
|
/*
|
||
|
|
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 "btHinge2Constraint.h"
|
||
|
|
#include "BulletDynamics/Dynamics/btRigidBody.h"
|
||
|
|
#include "LinearMath/btTransformUtil.h"
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
// constructor
|
||
|
|
// anchor, axis1 and axis2 are in world coordinate system
|
||
|
|
// axis1 must be orthogonal to axis2
|
||
|
|
btHinge2Constraint::btHinge2Constraint(btRigidBody& rbA, btRigidBody& rbB, btVector3& anchor, btVector3& axis1, btVector3& axis2)
|
||
|
|
: btGeneric6DofSpring2Constraint(rbA, rbB, btTransform::getIdentity(), btTransform::getIdentity(),RO_XYZ),
|
||
|
|
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 = axis1.normalize();
|
||
|
|
btVector3 xAxis = axis2.normalize();
|
||
|
|
btVector3 yAxis = zAxis.cross(xAxis); // 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.f, 0.f, -1.f));
|
||
|
|
setLinearUpperLimit(btVector3(0.f, 0.f, 1.f));
|
||
|
|
// like front wheels of a car
|
||
|
|
setAngularLowerLimit(btVector3(1.f, 0.f, -SIMD_HALF_PI * 0.5f));
|
||
|
|
setAngularUpperLimit(btVector3(-1.f, 0.f, SIMD_HALF_PI * 0.5f));
|
||
|
|
// enable suspension
|
||
|
|
enableSpring(2, true);
|
||
|
|
setStiffness(2, SIMD_PI * SIMD_PI * 4.f);
|
||
|
|
setDamping(2, 0.01f);
|
||
|
|
setEquilibriumPoint();
|
||
|
|
}
|
||
|
|
|