Building a torch

The lighting effects used in this episode are of course all faked. The use of alpha blending is what makes the lighting look so much more elaborate than it really is. There are four layers of alpha blending that are used. The alpha blending layers are all solid blocks who's purpose is to make the item beneath them darker. The layering of these layers are tied to the way that the painters algorithm based display draws the 3D view. The first layer is positioned over the tiles that make up the far view. Over top of this layer is the medium view followed by another alpha block. Over the medium tint is the near layer which then has a near alpha block. Finally we have the point blank view covered by a special torch layer.

Alpha layers are cumulative in how the darkening is applied so the result is the banding effect that has more distant walls appearing to be darker than nearer walls. As I mentioned, there is a special layer that is used for the torch. This layer has a varying level of alpha values that are randomly calculated every few frames to create the flickering effect. The code for this effect is as follows: