I'm trying to bounce a polygon that has both velocity and angular velocity off a (immovable) wall when one of the vertices collides with it. I can detect the collision, and I've worked out how to calculate the inputs and know what outputs I need, but haven't been able to find or work out an implementation for the response. Any help would be greatly appreciated. function collisionResponse( c, // object center of mass position v, // velocity of object a, // the angular velocity of the object p, // point of contact with line n // normalized normal of line ) { // Make a vector from center mass to contact point cp = p - c; // Total velocity at contact point (add angular effect) pv.x = v.x - cp.y * a; pv.y = v.y + cp.x * a; // Reflect point of contact velocity off the line (wall) rv = reflect( pv, n ); // magic happens.. result.v = ?? // resulting object velocity result.a = ?? // resulting object angular velocity return result; }