CGTalk - Subdivision surfaces crashing render

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fango

01-19-2003, 12:29 PM

hello there,

i m running somewhat into a little problem, i converted my poly cage into subd and when i try to render, it crashes (i think it might be a low memory issue, 512m ram , swap file 1.2gig on separate partition).

i searched and only find Steven stahlberg's thread about random crashes when rendering textured subd's (his not being a memory issue obviously). i wondered how he got it fixed, i think they solved the issue by making a bot file out of his textures, though on my scene file, there is just basic procedural shaders.

now when i keep everything in polys and just hit smooth, everything's fine. the problem is i plan on trucking quite close to the model and it tesselates quite strongly the closer i get (thus the subd solution). that and polysmooth's smoothing algorithm is weaker thant subd's (obviously).

i m thinking converting to subd and then convert back to poly adaptative, though this won t help with close up shots.

i m using maya's default renderer, not mray.

the scene file's rather big... about 140k quad, not including nurbs for the chainmail and hair. that should average to the mill tris. (again, polysmoothing renders fine.)

any suggestions deeply appreciated.

Stahlberg

01-20-2003, 01:20 AM

Sorry, I have no solution, making bots wasn't it... nothing I did helped, except when I started deleting stuff. Deleting the shaders helped remove the crashing, or make them come less frequently. Deleting the biggest textures helped. Deleting the SubD helped. Deleting lights... etc. Obviously some kind of cumulative problem, a memory leak or something. It will render a few frames then crash (same amount of frames no matter which frame is the first one). A weaker machine will render less frames, a stronger more. Rotating the camera over to the opposite side of the model would make the same scene crash after 20 frames on my fastest machine, that didn't crash at all from the front.

The way I see it is this is just another proof that the Maya renderer sucks, hope they fix it soon. :annoyed:

fango

01-20-2003, 11:52 AM

aarrgghh so no subD topology for me :surprised

thanks for the answer steven, i think i ll add your thread and this one to the maya faq (even if there s no solution.)

i found quite ironic that maya's own renderer isn t bulletproof supporting it s own subds... :P

sp0rk3d

02-19-2003, 02:59 AM

yeah i have run into this problem a lot also.... maya has some problems with subdivs..... i crashed maya trying to edit the UV's of a subdiv the resource manger said i was using 2 GB ram to try and move ONE UV!!!!!..... hahahaha.... well rendering textures always seems to be a problem with subdivs also... i tend to model useing subdivs to check progres but i don't use hierarchitcal subs like steven does... then texture, rig, animate, the poly and ad a poly smooth to the history of the poly and turn up the divisions as needed by the shot.... have yet to figure out how to make the textured subdivs render better.... a couple friends at pixar who use subs say use renderman to render.... :( but i haven't learned renderman yet so... smooth polys for me :/

cbroquard

11-30-2004, 07:13 AM

Some new thoughts:
1. In the Maya help files, it mentions without great detail that "on some 32bit machines, (irix, windows etc.) it is not possible to have a process exceed 1.6Gb." It even conversationally mentions that it doesnt matter how many gigs of space the machine has, a process cannot exceed this amount. I have a huge number of lights in my scene (simulated broadway lights), all instanced to save space, with procedural textures; I render without raytracing with Maya software render, and it's fine, but with raytracing turned on, it crashes with the free memory exception thrown. Interestingly, the Maya help file does not mention the 64bit machine possibilities, my machine is a dual 64bit Opteron with 2Gb of RAM. I need to render files that are large like this, but can't due to the render crashes and free memory exceptions. ANy clues to solve this would be much appreciated.

Obviously, I know that a scene with 600 or so lightbulbs all raytraced is going to be a rendering nightmare, but certainly ther'e got to be a way.

Best, Jacques Broquard

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