Alembic visibility and irradiance map

[CGMas]

hi,

There's a problem with irradiance and alembic's animated visibility.

Make a plane, add an edge support and a vray subdivision attribute.
Parent the plane to a group
Animate visibility of the group then bake an alembic.
Load it in maya and you will see that irradiance map samples are generated on the plane without subdivision.
So the samples on the faces created by the edge support are deformed by the subdivision.

If you I could send you a file that recreate the problem.

What can I do ?

Thanks,

Max

[yolov]

It should render non-subdivided in all cases (with or without GI).
It's just that the alembic exporter doesn't read the vray attributes. You could simply add the attribute to the shape node after you have imported the alembic back to the scene.

[CGMas]

Ok Sorry, I made an error with the process to recreate this error.
The vray subdivision attribute on the shape node is applied at the end. On the alembic.

I don't know if I'm allowed to put it here that way but here is a scene example to reproduce the problem :
http://we.tl/T6RcH2Uoan

[yolov]

Hmm, that's odd. Can you share the scene or a simple example for this?
What's your OS, VRay and Maya versions?

[CGMas]

Ok Sorry, I made an error with the process to recreate this error.
The vray subdivision attribute on the shape node is applied at the end. On the alembic.

I don't know if I'm allowed to put it here that way but here is a scene example to reproduce the problem :
http://we.tl/T6RcH2Uoan

The file's just there.
I'm using the latest nightly build of vray 3 for maya 2015 on Win 7

[yolov]

Yes, there seems to be something wrong about this.
I'll let you know when we have some news, for now I'm forwarding this to our developers.

[yolov]

Removing the visibility key and adding it again makes it render fine. It seems there is a problem when we're trying to read this key when set before exporting to alembic.

[CGMas]

Yes, this is the same conclusion I had, but I wasn't sure.
So, while waiting for a fix, I think we will tesselate our objects a little more to hide the effect, which is not a good a solution.
Because we cannot break then key again visibility at this step of our pipeline.

If you find a way to fix it let me know !

Thanks,

Max
Supamonks Studio

[ivaylo.ivanov]

Another work around is to use OpenSubdiv. It works in a different way and seems to not be affected.

[CGMas]

Yes, I've seen that but it add time to compile geometry, so for a scene with a lot of geometry it can be long to compile all the geometry !