Method ApplyForcesAndFriction

engine/Poseidon/World/Simulation/Simul.cpp:673–812

#endif

void Entity::ApplyForcesAndFriction(float deltaT, Vector3Par force, Vector3Par torque, const FrictionPoint* fric,
                                    int nFric)
{
    float frictionCoef = 10;
    float angularFrictionCoef = 1.0f;

    Vector3 wAccel = force * GetInvMass();
    Vector3 oldSpeed = _speed;

    _angMomentum += torque * deltaT;
    _speed += wAccel * deltaT;

    float rigid = Rigid();

    _speed += _impulseForce * (GetInvMass() * rigid);
    _angMomentum += _impulseTorque * rigid;

    _impulseTorque = VZero;
    _impulseForce = VZero;

    Matrix3Val orientation0 = Transform().Orientation();
    Matrix3Val invOrientation0 = InvTransform().Orientation();
    if (_shape)
    {
        _invAngInertia = orientation0 * InvInertia() * invOrientation0;
    }
    else
    {
        _invAngInertia = M3Zero;
    }

    _angVelocity = _invAngInertia * _angMomentum;

#if 1
    if (nFric > 0)
    {
        AUTO_STATIC_ARRAY(Vector3, pVelChange, 128);
        pVelChange.Resize(nFric);

        Vector3 velChange(VZero);
        Vector3 angMomChange(VZero);
        float mass = GetMass();

        Vector3 wCenter(VFastTransform, ModelToWorld(), GetCenterOfMass());
        float sumFricCoef = 0;
        for (int f = 0; f < nFric; f++)
        {
            const FrictionPoint& fp = fric[f];
            sumFricCoef += fp.frictionCoef;
        }
        // sum may exceed 1 when in water; keep combined force in range
        float invSumFricCoef = sumFricCoef > 1 ? 1.0f / sumFricCoef : 1;

        float angMomFriction = 0;
        for (int f = 0; f < nFric; f++)
        {
            const FrictionPoint& fp = fric[f];
            Vector3 pCenter = fp.pos - wCenter;