Hello,
Sorry for stupid question but recently I palyed with sphere environment mapping and found out some interesting effects.
So the question is: How sphere environment mapping is caclulating? Do I need vertex normals at the object where I would like to apply env.mapping?
Reflect the view vector about the normal, add the z axis (+1 to v.z), normalise. Your texture coordinates are then:
u = v.x * 0.5 + 0.5
v = v.y * 0.5 + 0.5
Obviously, this is all in eye space.
At what point are texture matrices applied in this process?
I’ve never been able to get anything useful to happen when I try to apply a texture matrix to an environment map. It always ended up as garbage.
The texture matrix is applied after texgen so trying to rotate a conventional spherical reflection map isn’t going to work.
Texcoord rotation with a texture cube map would work fine though.
-Brian