internal static float GetJacVelocity(float3 linear, ContactJacobianAngular jacAngular, MotionVelocity velocityA, MotionVelocity velocityB)
        {
            float3 temp = (velocityA.LinearVelocity - velocityB.LinearVelocity) * linear;

            temp += velocityA.AngularVelocity * jacAngular.AngularA;
            temp += velocityB.AngularVelocity * jacAngular.AngularB;
            return(math.csum(temp));
        }
        internal static float GetJacVelocity(float3 linear, ContactJacobianAngular jacAngular,
                                             float3 linVelA, float3 angVelA, float3 linVelB, float3 angVelB)
        {
            float3 temp = (linVelA - linVelB) * linear;

            temp += angVelA * jacAngular.AngularA;
            temp += angVelB * jacAngular.AngularB;
            return(math.csum(temp));
        }