btContactSolverInfo.h

Go to the documentation of this file.

/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/

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.
*/

#ifndef CONTACT_SOLVER_INFO
#define CONTACT_SOLVER_INFO

enum    btSolverMode
{
    SOLVER_RANDMIZE_ORDER = 1,
    SOLVER_FRICTION_SEPARATE = 2,
    SOLVER_USE_WARMSTARTING = 4,
    SOLVER_USE_FRICTION_WARMSTARTING = 8,
    SOLVER_USE_2_FRICTION_DIRECTIONS = 16,
    SOLVER_ENABLE_FRICTION_DIRECTION_CACHING = 32,
    SOLVER_DISABLE_VELOCITY_DEPENDENT_FRICTION_DIRECTION = 64,
    SOLVER_CACHE_FRIENDLY = 128,
    SOLVER_SIMD = 256,  //enabled for Windows, the solver innerloop is branchless SIMD, 40% faster than FPU/scalar version
    SOLVER_CUDA = 512   //will be open sourced during Game Developers Conference 2009. Much faster.
};

struct btContactSolverInfoData
{
    

    btScalar    m_tau;
    btScalar    m_damping;//global non-contact constraint damping, can be locally overridden by constraints during 'getInfo2'.
    btScalar    m_friction;
    btScalar    m_timeStep;
    btScalar    m_restitution;
    int     m_numIterations;
    btScalar    m_maxErrorReduction;
    btScalar    m_sor;
    btScalar    m_erp;//used as Baumgarte factor
    btScalar    m_erp2;//used in Split Impulse
    btScalar    m_globalCfm;//constraint force mixing
    int         m_splitImpulse;
    btScalar    m_splitImpulsePenetrationThreshold;
    btScalar    m_linearSlop;
    btScalar    m_warmstartingFactor;

    int         m_solverMode;
    int m_restingContactRestitutionThreshold;
    int         m_minimumSolverBatchSize;


};

struct btContactSolverInfo : public btContactSolverInfoData
{

    

    inline btContactSolverInfo()
    {
        m_tau = btScalar(0.6);
        m_damping = btScalar(1.0);
        m_friction = btScalar(0.3);
        m_restitution = btScalar(0.);
        m_maxErrorReduction = btScalar(20.);
        m_numIterations = 10;
        m_erp = btScalar(0.2);
        m_erp2 = btScalar(0.1);
        m_globalCfm = btScalar(0.);
        m_sor = btScalar(1.);
        m_splitImpulse = false;
        m_splitImpulsePenetrationThreshold = -0.02f;
        m_linearSlop = btScalar(0.0);
        m_warmstartingFactor=btScalar(0.85);
        m_solverMode = SOLVER_USE_WARMSTARTING | SOLVER_SIMD;// | SOLVER_RANDMIZE_ORDER;
        m_restingContactRestitutionThreshold = 2;//resting contact lifetime threshold to disable restitution
        m_minimumSolverBatchSize = 128; //try to combine islands until the amount of constraints reaches this limit
    }
};

#endif //CONTACT_SOLVER_INFO