Get closest location to the grid, subtract this location position from the particle position, dot product to the location normal, depending on the value you can know if it's back face or front face. On Sep 10, 2015 8:58 AM, "Olivier Jeannel" <facialdel...@gmail.com> wrote:
> That's something I've wondered for while and since I'm waiting in a > starbuck... > Let's say you have a fied of particles. In the middle of the field you put > a grid. > How do I recognize the particles that are on the front side and the > particles that are on the back side of the grid ? > > :) >