Using the given information, is it possible to solve the new travel direction of the smiley face? To clarify, I am casting a ray using the Möller–Trumbore ray-triangle intersection algorithm.http://http://en.wikipedia.org/wiki/M%C3%B6ller%E2%80%93Trumbore_intersection_algorithm by casting the ray in the travel direction of the smiley face, I can determine how far away from said plane I am. When I hit that point, is their a mathematical way to, in this specific case, stop the x axis from advancing, and advance the z axis at half the rate? If any clarification is needed please let me know. Thank you.