by Nadnerb » Fri Jun 13, 2008 7:01 pm
Okay, as the one who pointed this issue out in the first place, and seeing that it still doesn't appear to have been accurately communicated, I'll clarify further. Plasma uses the bounding box of an object to determine whether it is within the field of view, and therefore, whether to render it. If the bounding box of an object is not within the view frustum, it will not be rendered.
This bounding box is written to the prp file by the plugin and is not calculated or modified by the engine at runtime. This means that if the bounding box were written incorrectly, the object in question would appear and disappear, at random. (while actually being based on whether whatever bounding box, as actually written, was visible or not)
The problem with wavesets is that the geometry affected by them is moved. In the case of a waveset which is flat, and therefore has no vertices at water level, the surface of the water is actually rendered outside of the object's bounding box. When this difference is pronounced, the waveset will appear to vanish at the edges of the view as the bounding box leaves the frustum.
There is another, slightly less obvious use for the bounding boxes. They are used in plasma's runtime z-sorting, when enabled, and if the bounding box does not accurately represent the rendered object, it may be sorted incorrectly. (causing the well known z sorting issues such as far objects appearing in front of near ones, and the "x-ray" effect, caused by incorrectly sorted transparent textures)