Reduce Memory Usage with Ocean Mesh

[Joelaff]

I have a 6K render using Ocean mesh, and I need to get the subdivs higher, but am running into memory issues. I am only rendering a portion of the image (the shot is cropped in post). Is there a way to limit the visible area that is tessellated for Ocean Mesh mode (for the distant ocean)?

Is a Cutter processed first, or after the distant polygons are already created? (Could it be handled first if it is not??)

We are already rendering in standalone because it uses less memory than rendering in Max, and lets us get higher Ocean Subdivs.

Would a VRayDisplacement on a big plane be more efficient? For this shot we do not have any actual simulation, just ocean.

Would Max render regions help? Jigsaw with Deadline? I tried these briefly, but I think neither reduced memory usage. However, I had some other issues at the time; so the test is not really valid.

Any thoughts? Thanks.

I suppose zooming the lens in would help, but the shot is 3d tracked, and anamorphic too

[Svetlin.Nikolov]

Oh yes, I suggest that you go with displacement on a plane - it should be much more efficient. The cutter in mesh mode just removes voxels from the grid before meshing, so in ocean mesh mode the content inside the grid will be cut, but the full ocean would still be created. And this would also be the case with a Simulator + V-Ray Clipper - the full mesh will be generated first and then clipped. So I think the V-Ray displacement on a plane would be the best approach.

Cheers!

[Joelaff]

Thanks for the reply. That is rendering a lot faster. There is one shot where we will still need the simulation and the ocean mesh horizon. Any tips for optimizing that? That one will be full frame at least (or nearly).

Is there any way that the clipping could happen before the tessellation? That could save a lot of memory and processing time, no?

[Svetlin.Nikolov]

Not without a change in the code I'm afraid - let me try to do a quick patch - will try to reduce the polygons outside the cutter geometry for the ocean so the cutter (still) wouldn't be working correctly for the ocean extension, but will use much less memory and then you would be able clip it with the V-Ray Clipper. Would this work for this shot?

[Joelaff]

I'm not sure I fully understand, but reduced memory would be amazing! Thanks.

I think you are saying it wouldn't keep the extension from rendering outside the cutter, but it would use less polys in the area outside the cutter. That is no problem.

[Joelaff]

If you are able to do this please let me know if it will be safe to animate the cutter by locking the cutter to the camera frustrum (with some slack). In other words, sill it produce nasty artifacts if I clip it to the visible area only? Thanks again. You are a life saver.

[Svetlin.Nikolov]

Aha, I got something more than I thought with a quick hack - the idea is that you would need to use Cutter AND Clipper, but the memory usage should be much much lower:



This will be in tomorrow's nightlies.