Potential issues and how to address them

Although we aren't facing any of these issues at this very point, most 3D games will have to deal with them as soon as basic shadows are established using this method.

Shadow acne is a graphical artefact that can be summarized as horrible tearing, where lit areas are horribly defaced with dark and white lines closely nested together. This happens because shadow maps are of finite size and pixels that are right next to each other will end up spanning a small distance on actual, real geometry being shaded. It can be fixed by simply adding or subtracting a simple bias floating point value to or from the shadow map's depth sample inside the light pass shader. This floating point value would, ideally, not be a constant and instead depend on the slope between the point on the geometry and the light.

Peter panning can be described as shadows that appear to be floating away from the geometry that casts them. Adding the floating point bias to...