I know I need to project the vertices of my polyhedra on a whole bunch of axes, i've read these axes are the normals to each of the faces of one polyhedra (or is it both?). I've also read i use the cross product of each edge of one collidable with each edge of the other collidable. So lets say i have 2 polyhedra each with 8 faces and 12 edges. Therefore there would be 8 + (12*12) = 152 axes to project and then subsequently test? Is that correct?
Also since i dont know whether my faces are CW or CCW, my normals could be pointing inside or outside, does this matter? For example lets say i project onto an axis that is a normal from one of the shapes facing inwards, as long as both polyhedra are projected using this same normal, will this effect the algorithm?
Thanks for any input!
In short, the only planes you need to check are those that are defined by the faces of your objects; that is, the normal of the faces is the normal of the planes to check. The direction of the normal doesn't matter, since you're just projecting the vertices anyway.
Also note that this only works for convex meshes, and isn't necessarily the quickest way to do these kinds of checks. You might want to look into XenoCollide or GJK instead; those are becoming standard.