Graphics: Difference between revisions

Pease acknowledges that even occlusion testing was too CPU-intensive until they lowered the number of rays being emitted and started altering their emission angles even when the camera remained still, in order to catch any polygons that the first emission of rays missed; this is why distant polygons, when suddenly revealed by the camera, sometimes are culled at first and then appear a moment later (pictured, right): because the rays didn't hit them on the first pass. More generally, a distant object can be accidentally culled if it's only visible through a narrow slit, because the rays have a low probability of passing through the slit and hitting the objects behind it. A similar problem occurs when modders experiment with outdoor levels that have uneven ground (natural terrain): many of the ground polygons will be culled, making the map look like there are holes everywhere.