don't certain types of lighting (like reflections for example) depend on the angle we're looking at it from? So how would the precomputed offline lighting change as the camera (user in the video game) move around and change the angles and distances from which they observe the scene?
imm
what exactly does "baking" the lighting onto the map entail? And would we have to precompute the texture map for different angles of lighting/eye position?
prathikn
@jballouz not entirely sure but my guess is that since we have certain light sources at known positions we can calculate the shadows associated with it and that's where precomputed lighting comes into picture. Maybe for aspects like reflection (which are impacted by angle as you mentioned) we can do that online?
sarukkai
@imm the baking of the texture map involves precomputing a version of the texture map with aspects of the lighting that are independent of eye position—areas in shadow, intensity of light falling on an area, etc.
kencheng
@jballouz: Yes, the light from a point should change as we change the viewing angle as per the BRDF. However, most of these things are just hacks. In this case, we just assume that the BRDF for a point is equal in all directions (and it's probably not too far off from real life). For things where the BRDF must be non-equal (aka reflections), we use other hacks (like http://cs248.stanford.edu/winter19/lecture/modernrast/slide_037)
don't certain types of lighting (like reflections for example) depend on the angle we're looking at it from? So how would the precomputed offline lighting change as the camera (user in the video game) move around and change the angles and distances from which they observe the scene?
what exactly does "baking" the lighting onto the map entail? And would we have to precompute the texture map for different angles of lighting/eye position?
@jballouz not entirely sure but my guess is that since we have certain light sources at known positions we can calculate the shadows associated with it and that's where precomputed lighting comes into picture. Maybe for aspects like reflection (which are impacted by angle as you mentioned) we can do that online?
@imm the baking of the texture map involves precomputing a version of the texture map with aspects of the lighting that are independent of eye position—areas in shadow, intensity of light falling on an area, etc.
@jballouz: Yes, the light from a point should change as we change the viewing angle as per the BRDF. However, most of these things are just hacks. In this case, we just assume that the BRDF for a point is equal in all directions (and it's probably not too far off from real life). For things where the BRDF must be non-equal (aka reflections), we use other hacks (like http://cs248.stanford.edu/winter19/lecture/modernrast/slide_037)