Lewis Taylor

Scene import is doing a brute force load and it's trying to use your existing OBJ level containers settings.
The objects coming in have a higher opinion than any render settings/geo settings so that is why you see no change.

You need to enable velocity blur on the OBJ level containers you need blur on, as if they were going to mantra.
Part of the reason that the whole notion of pulling in data via SOPs Vs writing out USD and loading properly
is just bad news in general. I get it's a quick way to render, but you pay a price in other areas.

So just to be clear, the Scene Import will pull stuff in with whatever values are in OBJ and they have stronger
opinions.

animating at OBJ level is dangerous, if you plan to export this stuff the transforms at OBJ level
Are not accounted for. If you use a vol vis SOP and set viewport Max Vis Res to 64-128 you will still see
reasonable detail and have very good performance, without the dangers or animation limitations of OBJ level.

There is no workaround. Whitewater is best done as rasterized volume with spec layer on top
that uses the gradient of volume. There are only three engines that support this workflow, two of them
are public. Mantra and 3Delight. Hyperion at Disney supports this, and I'm pretty sure prman internally
at ILM does.

This really needs to be addressed, as feeding volumes is much faster to render. The Mantra method still required the
presence of the gradient SDF, 3Delight will create the gradient SDF on the fly if it's not present, it also supports
frustum volumes.

I think Karma XPU needs to support using the gradient SDF as a Normal for the spec layer which is layered on top of
the volume. It's the default method we use in Studios to render White Water for several years now, and if Karma is the replacement to Mantra it needs to have feature parity with a core VFX element render.


L