Scene renders at HD1080 - anything larger hangs at compiling geometry forever

[wizzackr]

We have a fairly complex scene (fur, lots of proxies) we urgently need to render but run into this problem: The scene renders just fine at HD1080 resolutions which we used for scene setups. When moving into production and trying to render the very same scene with exactly the same settings at 4k the translator is stuck at "Compiling Geometry" forever. RAM usage rises super slowly but sky-high until it eventually dies.

I cannot think of anything we use in the scene that would be resolution dependant when it comes to compiling the geometry... Anyone any idea? This is pressing...
J

[vfx_film_televsion]

Displacement may be resolution dependent!

[wizzackr]

Displacement may be resolution dependent!

Yeah, we turned it off in the globals to make sure that's not it. It's crazy really: 12gb RAM at 1920x1080 and renders just fine - but once we set output resolution to 3076 width for example it sucks up 64gb of memory, does not start to render at all and crashes. Oh man, long night of debugging ahead

[Morbid Angel]

Hey wizzackr, couple of things to try: turn off displacement / subdivision in globals (subdivision also not just displacement) Also fur can be dynamically tessellated. Depends on what fur you are using (yeti, xgen) whatever vray may subdivide the strands much like displacement. If you turn off the fur also in globals does the problem go away? If so this means the fur subdivs need to be reduced. Lastly you can render everything greyshaded and see if perhaps its texture related (though I doubt it) but if you for example have a large set of mip mapped (tiled) textures at large res they can eat up some ram...

[wizzackr]

Hey wizzackr, couple of things to try: turn off displacement / subdivision in globals (subdivision also not just displacement) Also fur can be dynamically tessellated. Depends on what fur you are using (yeti, xgen) whatever vray may subdivide the strands much like displacement. If you turn off the fur also in globals does the problem go away? If so this means the fur subdivs need to be reduced. Lastly you can render everything greyshaded and see if perhaps its texture related (though I doubt it) but if you for example have a large set of mip mapped (tiled) textures at large res they can eat up some ram...

Thanks for the suggestions, Dmitry - much appreciated. This really is super strange: We can render the scene normally at 1080p with everything turned on (RAM usage maxes out at 24GB), but even with everything globally turned off (displacements, textures, subdivision, proxies, particles and fur) anything above this res stalls the computers. RAM super slowly crawls up until it hits the ceiling (64GB in our case), then it crashes. Man... Super difficult to debug, too, as even full diagnostic messages don't reveal anything. It simply hangs on 'compiling geometry' until it runs our of RAM

[Morbid Angel]

Can you share the scene with me? I can take a look at it.

[vfx_film_televsion]

Hide group after group and Render. try to isolate the error as much as possible

[wizzackr]

Someone found the culprit - was a faulty NURBs surface that was tesselated at ridiculous levels. Man... Thanks for the help guys. Now 10 h to deadline - but we can actually render now, that helps

[Morbid Angel]

glad you sorted it out.