Tutti-frutti effect

The tutti-frutti effect occurs when an area of a wall has no wall texture defined that covers it and there is no game area directly behind it. In this case, junk shows through.

Tutti-frutti can be caused in several ways:
 * 1) If a wall is taller than its texture, then the texture is tiled vertically. But the Doom rendering engine starts new tiles only at 128, 256, 384, etc. If the texture is less than 128 units tall, horizontal bands will be left undefined.
 * 2) If a texture with transparent areas is used as an upper or lower texture on a two-sided wall, the content of the transparent areas is undefined. (By definition, only the middle can see through to the sector behind the wall.)
 * 3) If a texture with transparent areas is used as the texture on a one-sided wall, the content of the transparent areas is undefined.

This article is based on information in the Unofficial Doom Specs.