Hello all, I'm working on coding a program that tracks photons based on Compton Scattering. However, I'm having an issue on how to deal with photons with multiple scatters. So, phi (polar) and theta (azimuthal) range from 0-pi/2 and 0-2pi, respectively, based on a random number generator. How do I calculate the new dx, dy, and dz after the first scatter. I guess I'm just not sure how to represent the incident vector and its effect on the vector after collision.