High Resolution Voxel Remesh

Hey Steph, I was wondering if there is still a limit attributed to voxel remesh? That troublesome dragon sculpt of mine is currently 14.9m verts (3gb RAM) so I’ve tried remedying at a high level to reduce vert count while retaining detail and whether voxel res is set to 1500 or 2400 the remeshed model tops out at 1.48m verts (985MB RAM)
Any resolution above 2400 is instant crash!
Not sure if Nomad/iPadOS 15 is managing the extra ram RAM allowance very efficiently as I still have 75% available so wouldn’t expect such frequent crashes

Hope that makes sense

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Note that the output vertex count depends on the geometry, if you take a sphere the max is around 5.5M.
Ultimately, voxel remesher is not meant to be used with such high poly count.

So there’s two thing;

  • voxel has has a resolution limit of 1200 (there is a meaning behind the limit), so there is no difference between 2400 or 1200 (unless you used the “rebuild multires” slider).
    Higher values are allowed because the detail slider is shared with dyntopo (and dyntopo doesn’t have this limit).
    I’ll raise the value for the next release but the performance won’t scale well .
    A grid of 2000 means 9 billions cells, and there is no hierarchical support.
    Maybe you should switch to dyntopo (with masking)

  • your crash is not caused by the voxel resolution itself but rather by the reprojection pass, which depends on your base geometry (so the culprit is the 15M poly mesh).
    But that part is going to be improved a lot on next release, so the bottleneck will be on the voxel resolution again.

The memory peak happens during an algorithm so you don’t have the chance to see the value rising.
Your 75% gets eaten in an instant.
You see huge memory peak in 3d software such as blender when doing operations (much higher than in Nomad).
The thing that people ignore is memory swapping, on desktop if you exceed the RAM amount, the OS will simply use the disk space as if it was RAM. It’s very slow but it prevents an hard crash.
Mobile devices can’t do that (and probably won’t be).


Thanks for clarifying that Stephane, once I have this dragon to a manageable level I’ll make sure that future sculpts play nicer :wink:

Just my opinion from my experience with Nomad, but 15m is far too high for the current level of detail. You could easily reduce the count to 1-3m total (or less) and still keep the detail level roughly the same. At 15 million, I’d expect it to be showing individual scales all over the head, body, and wings.

I know my heads aren’t super detailed, but you can achieve details down to pore level with 2-3m on a head easily. The entire head, body, fingers, toes, and teeth of a recent sculpt (with no optimization since I was just doodling) was at only 850k with no smooth shading.

Having the ability to achieve these higher counts doesn’t always mean that it’s needed in every case with a program like Nomad. Usually, you can save those huge counts for higher frequency details. And even then, you can specifically target those areas with the dynamic topology on subdivide.

Like I said, just my opinion…lol. But, I still can’t wait to see how this guy turns out when you get done with it.

Hey Spork, yeah 15 is certainly hefty and it started out as a head sculpt (4m) and it literally grew arms and legs (and tail and wings) I will be adding a lot more detail for sure, I’ve processed through zremesher so I’ve got to a more manageable 7m total… now I can get back to the fun bit of sculpting horns and scales :wink: