Isotropix Forums

I am trying to replicate one of our internal scenes that uses a lot of USD assets in the PLE version of Clarisse. (trying to evaluate it as a potential set dressing tool).

But often the scene gets stuck on this step:

"Building tessellation UV maps of object '<some object>'"

For some assets this can take up to 2 or 3 minutes to complete. On others it appears to get stuck indefinitely on this stage (or at least I give up after 20 minutes or so). What is this step doing, and is there a way I can either skip it or restructure our assets to optimize it?

Edit: Could it be that if the asset contains meshes that do not have UV's defined that it can really slow down? I'm trying to find the commonality between the assets that take a long time to go through this step.

Thanks!

Hi,
This happens when an object has subdivision enabled: In this case, we need to also tessellate the UV maps.
Now why does it take this long on some assets, I've no idea. Maybe a bug? Or maybe the asset in question is huge (e.g. if a mesh with a million primitives is tessellated, this step can take quite a while) If you can share the USD assets where this happens, we could have a look at it.
And if you don't want tessellation, then you have 2 choices: The first one is to disable them directly in the USD stage (subdivisionScheme attribute set to "none", see https://openusd.org/dev/api/class_usd_g ... 6cfafb7c0a)
And the second is to disable it in Clarisse directly: "Enable Subdivision Surface" attribute in the "Geometry > Subdivision Surfaces" category on all geometry objects.

Thanks so much. I will try disabling it in Clarisse directly for now. Unfortunately I cannot share the USD itself.

Now that I know what this step does, I can try to figure out why some assets are so slow. None of them are particularly large - often no more than tens of thousands of polygons per asset as far as I recall - but now I can inspect each asset more closely. If I can figure it out, I will let you know. Thanks again.

I am trying to disable the subdivision on these assets, but I don't see the option for "Enable Subdivision Surface". This is because, apparently, USD bundles do not offer that option. Unfortunately I cannot reference the USD assets directly because:

1) I need to move them as single assets, not as a completely expanded hierarchy of individual meshes
2) The number of nodes in the Explorer becomes far too large with close to 10,000 instances of about 300 individual assets, each with hundreds of sub-meshes. Clarisse basically shuts down with so many individual nodes.

Is there any way to disable subdivisions for USD bundles?