The console could only draw so many shapes at once, and in Andy Gavin's words "the Playstation had no z-buffer, and hence no easy way to sort polygons". Show too much and the game started getting "hitchy".

So Naughty Dog did the looking the night before. The camera moved "on a “track” through the world", so Gavin and Dave Baggett pre-calculated "the visibility and sort" for every spot on that track "ahead of time on the SGI workstations the artists used". "As long as you could never SEE more than a set number of polygons (800 for Crash 1, 1300 for Crash 2 or 3) from any given position we could have perfect occlusion and sort, with no runtime cost." Levels "often took several hours to process", built "over night (really 4am-11am, the only times the office was ever empty)". "Wherever we had too many polygons we'd add some leaves or whatever to occlude some distance. Wherever there were more polygons available to draw we'd pull leaves out."

The jungle, the ball and the counts in this film are our own simplified version, built in code.

Which game's hidden trick should we cut open next?

Source: Andy Gavin, "Making Crash Bandicoot – part 3", all-things-andy-gavin.com, 4 Feb 2011.
Unofficial. Not affiliated with or endorsed by Sony Interactive Entertainment, Naughty Dog or Activision.