Link to this picture
Severe texturing errors caused by use of non-power-of-two mip textures.
More severe texturing errors.
PVS demonstration. Nothing is around the corner...
PVS demonstration.
PVS demonstration. As we move around the corner, more geometry appears.
Surfaces without lightmaps are incorrectly drawn at full brightness.
Creating a 1 pixel square lightmap set to the surface's base light level is a quick and effective fix.
E1M1 model 0.
E1M1 model 1.
E1M1 model 2.
BSP models are also used for some pickups.
The Place of Two Deaths with BSP model pickups.