Mappers used to do that with games like Half-Life. A pipe would have a slight gap where it connects to a wall so there would be fewer polygons to draw. It had a big impact on frame rates back then.
Pfft. You could be better off func_walling the pipe. But yeah, basically you can imagine the engine (technically the visibility compiler in HL1's case) "tracing" all the 3D geometry, to calculate render culling. This would be broken up when it came in contact with obstructions on the floor/walls/ceiling, such as tables and hanging lights. Made optimization messier. Hopefully DaggerXL won't need to rely on these tricks and some talented modeller could some day remedy this and many other minor quirks with the game's original geometry.
In other news, the http://dftexture.webs.com/ is making more progress and the current prealpha allows you to try out texture replacers. Look for a "teaser" upload in the coming days.
Things are starting to slow down now that everybody's back to work and school, and I think we may need to bring another person onboard. Specifically for dungeon textures. Anybody interested in redoing Daggerfall's dungeon textures at double their original resolution - and maintaining the original feeling and shading of the originals, just overall crisper and more detailed, should post some examples in http://daggerxl.50.forumer.com/viewtopic.php?f=16&t=94 thread and drop me a line on that forum. Ideally, you should already know how Daggerfall's TEXTURE.### formats work, though I could always give a primer to anybody willing to learn. We'd love to have you!
One. Just one. :stare: