There must have been some cleverness in representing this data in a compact way, esp as it would have competed with the 150 kB/sec CD-ROM bandwidth streaming other asset data?
[1] https://all-things-andy-gavin.com/2011/02/02/making-crash-ba... Especially part 3.
> Our occlusion worked on a texture level. That is, if we had a giant polygon with a fern texture on it (think many leaves but lots of empty space) the occlusion could actually get rid of polygons behind the leaf part of the texture but leave the polygons seen through the alpha channel holes. No other game had that kind of detail in occlusion, and it paid off immensely. Given how small ground polygons could be in the distance, a little fern action went a long way.