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View Full Version : Massive bug with subdivision surfaces & UV maps



Captain Obvious
01-08-2009, 04:56 AM
There is a huge bug in Lightwave when you're using subdivision surfaces in conjunction with lots of UV maps (by lots, I mean hundreds).

Basically, memory usage goes nuts whenever the subdiv polygons are tesselated into regular polygons. Rendering, loading the scene, changing the subdivion level, anything, they all cause the memory usage to climb and climb and climb, so that subdiv meshes use about ten times their usual amount of memory.

Here's a link to the gofbugz or whatever:
https://secure.newtek.com/FogBugz/default.asp?19704_tg5kb7ml

evenflcw
01-08-2009, 05:27 AM
You are likely to get no answer or something dissappointing like "by design" because likely that just the way it's implemented! Pointmaps mean extra data needs to be stored for each point. I'm assuming then also that LW not only interpolates and stores to memory the 3d position for all points of the subdivided mesh, but also all interpolated uv positions and interpolated weightvalues. Considering the pointcount increases by 3-4 times for every subpatch iteration, that quickly becomes alot more data. Not only to store but to calculate aswell.

Hope they can think of a smarter way to handle it, rather than brute force.

Captain Obvious
01-08-2009, 02:22 PM
Ah, yes, but that's not the case though. The memory usage drops to normal levels as soon as the tesselation is done.