View Full Version : Mesh freezing crash - LW 2015

03-22-2018, 05:07 AM
Hi Forum,

I have one scene with a subD plane at 800.000 polys (base mesh) and Render SubPatch level 20.0. The mesh has displacements added. It render just fine despite polycount going very high.

Now, however,
If I make a sphere in modeler, tesselation 4, subD and load it into layout and set Render Subpatch level 10.0, when rendering LW uses up ALL available ram while freezing mesh, in this case more than 50Gb of ram, and then it crashes.
How can this be with a relatively simple mesh compared to the scene first mentioned?

It's completely reproducable, making such a sphere and using factory default Layout scene setup.

03-22-2018, 05:20 AM
I figured it out, the spheres were CC patches instead of SubPatch. Apparently that doesn't go well with that type of mesh.

03-22-2018, 07:04 AM
I think it's the numbers that became the problem: you ran out of ram.
CC patches have higher subdivision than subds.

Load a subd and a cc patched ball into layout to see the different ram requirements. CC patches are generally prohibitive above 5 while subds can go beyond 100. (In layout.)

03-22-2018, 08:28 AM
Yeah that was it. There's quite a big difference between the types considering Layout swallowed up 50+ GB of ram for a single sphere and would have continued eating more if available. But simple to avoid now knowing that!

03-28-2018, 01:03 PM
Somewhat related: Before submitting a scene to render, set your Subpatch Level and Render Subpatch Level to the same value. This should speed up rendering by skipping the 'Freezing' step.

Back when I was with Rhythm, we had an option in our custom render controller to match the Subpatch settings on Submit. I've always felt LightWave should have that option natively because the time savings can be significant even if you have only a few dense meshes in your scene. This might help with memory related crashing too.