public WheelContactPoint(RigidBody body0, RigidBody body1, ref IndexedVector3 frictionPosWorld, ref IndexedVector3 frictionDirectionWorld, float maxImpulse)
{
m_body0 = body0;
m_body1 = body1;
m_frictionPositionWorld = frictionPosWorld;
m_frictionDirectionWorld = frictionDirectionWorld;
m_maxImpulse = maxImpulse;
float denom0 = body0.ComputeImpulseDenominator(ref frictionPosWorld, ref frictionDirectionWorld);
float denom1 = body1.ComputeImpulseDenominator(ref frictionPosWorld, ref frictionDirectionWorld);
float relaxation = 1f;
m_jacDiagABInv = relaxation / (denom0 + denom1);
}
//response between two dynamic objects without friction, assuming 0 penetration depth
public static float ResolveSingleCollision(
RigidBody body1,
CollisionObject colObj2,
ref IndexedVector3 contactPositionWorld,
ref IndexedVector3 contactNormalOnB,
ContactSolverInfo solverInfo,
float distance)
{
RigidBody body2 = RigidBody.Upcast(colObj2);
IndexedVector3 normal = contactNormalOnB;
IndexedVector3 rel_pos1 = contactPositionWorld - body1.GetWorldTransform()._origin;
IndexedVector3 rel_pos2 = contactPositionWorld - colObj2.GetWorldTransform()._origin;
IndexedVector3 vel1 = body1.GetVelocityInLocalPoint(ref rel_pos1);
IndexedVector3 vel2 = body2 != null?body2.GetVelocityInLocalPoint(ref rel_pos2) : IndexedVector3.Zero;
IndexedVector3 vel = vel1 - vel2;
float rel_vel = normal.Dot(ref vel);
float combinedRestitution = body1.GetRestitution() * colObj2.GetRestitution();
float restitution = combinedRestitution * -rel_vel;
float positionalError = solverInfo.m_erp * -distance / solverInfo.m_timeStep;
float velocityError = -(1.0f + restitution) * rel_vel; // * damping;
float denom0 = body1.ComputeImpulseDenominator(ref contactPositionWorld, ref normal);
float denom1 = body2 != null?body2.ComputeImpulseDenominator(ref contactPositionWorld, ref normal) : 0.0f;
float relaxation = 1.0f;
float jacDiagABInv = relaxation / (denom0 + denom1);
float penetrationImpulse = positionalError * jacDiagABInv;
float velocityImpulse = velocityError * jacDiagABInv;
float normalImpulse = penetrationImpulse + velocityImpulse;
normalImpulse = 0.0f > normalImpulse ? 0.0f : normalImpulse;
body1.ApplyImpulse(normal * (normalImpulse), rel_pos1);
if (body2 != null)
{
body2.ApplyImpulse(-normal * (normalImpulse), rel_pos2);
}
return(normalImpulse);
}
