AA issues cryptomatte/MaterialName

[jerre.l]

We are having trouble rendering Cryptomattes with MaterialIDs in VRay for Maya.
You can find a MAYA example scene in the attachment.


Cryptomatte in ObjectIDs and AssetNames is working fine in vray.
But for MaterialIDs There is no anti-aliasing at all.

We're using Vray Next





We also tested with update1 but the same issue remains:
VRay does no anti-aliasing between materials for Cryptomatte






The issue is more obvious if we take a closer look:






The strange thing is that the PREVIEW which doesn't really work on Cryptomattes seems to do some kind of anti-aliasing (although we assume AA is correct?) :




A closer look:



It would be absolute overkill to switch separate materials to single meshes and/or to convert everything to uv's etc. This would get us too far and explode overall complexity.
Even in this simple sphere example it would be a shame to be forced to use another approach than the obvious one just because the renderer has trouble with AA of cryptomattes (not in preview mode though)

We did the test with Lambert Legacy materials and with VRay materials.
We're using Lamberts on some projects to get a 2D Look. For those projects everything else works fine (ie. all other Renderlayers/AOV's etc. except Cryptomatte).

The Cryptomatte issue on material IDs holds us back to gain precious/expensive time during compositing.
We tested the same issue with Arnold and got no issues whatsoever.
So far, vray is working fine for us. Hope we're just overlooking something and that the obvious solution is not far away. But we can't find it.

[jerre.l]

We are having trouble rendering Cryptomattes with MaterialIDs in VRay for Maya.
There is no anti aliasing at all.
Cryptomatte in ObjectIDs and AssetNames is working fine.

We're using


We also tested with update1 but the same issue remains:
VRay does no anti aliasing between materials for Cryptomatte



The issue is more obvious if we take a closer look:


The strange thing is that the PREVIEW which doesn't really work on Cryptomattes seems to do some kind of anti-aliasing (although we assume AA is correct?) :


A closer look


It would be absolute overkill to switch separate materials to single meshes and/or to convert everything to uv's etc. This would get us too far and explode overall complexity.
Even in this simple sphere example it would be a shame to be forced to use another approach than the obvious one just because the renderer has trouble with AA of cryptomattes (not in preview mode though)

We did the test with Lambert Legacy materials and with VRay materials.
We're using Lamberts on some projects to get a 2D Look. For those projects everything else works fine (ie. all other Renderlayers/AOV's etc. except Cryptomatte).
The Cryptomatte issue on material IDs holds us back to gain precious/expensive time during compositing.

We tested the same issue with Arnold and got no issues whatsoever.
So far, vray was working fine for us. We guess we're just overlooking something and that the obvious sollution is not far away. But we can't find it.
Projects may need a lot of workarounds (= cost more) if we cannot use Cryptomatte.

Could you please help us out with this issue?

[nikolay.kusht]

I would like to note that Cryptomatte render element is supported only when rendering in Bucked mode. The Interactive Photorealistic Renderer(IPR) should not be used as a reference since it would not display the Cryptomatte correctly.

Could you give us more details on what exactly mean by "Cryptomattes with MaterialID"? Note that the Cryptomatte ID mattes are determined by the following types:
Node name
Material name
Node name with hierarchy
V-Ray user attribute
Asset (reference scene) name
Sub object name

Which one do you use? Is it possible to send us an example scene?

For more information please refer to our online documentation:
https://docs.chaosgroup.com/display/...tte-Parameters

Please note that currently the "Material name" ID type is not supported if you are rendering with CUDA

I have noticed that you have also reported this to support@chaosgroup.com. Let's continue the communication over the emails.

[MadMikeDe]

Has any progress been made on this issue?

[nikolay.kusht]

After further investigation, it turns out that the issue was indeed present in V-Ray Next, hotfix 1, but since then we had made a lot of improvements and changes the issue is not occurring with the latest official build of V-Ray Next and V-Ray 5 for Maya.

If you notice anything with the latest builds, please let us know.

[MadMikeDe]

It is still an issue with Vray 5 1.3 for 3dsMax 2021

[MadMikeDe]

So i just realized that the search engine dropped me in the Vray for Maya section of the forum, oops. I'll see if I can find a similar thread for 3dsmax, or create a new thread.

[nikolay.kusht]

If the issue is present on both platforms it is ok to have your results here. Please send us your scene so we could take a look. Also, are you using the latest version of V-Ray 5?

[MadMikeDe]

I don't have a scene at the moment that I can share due to client NDAs, but it's easy to reproduce.
Create any object that has multiple material face IDs,
Apply a Multi/Sub-Object material
I've been using the new VBF layer masking for testing

I'm using Vray 5 v1.3

If I get time, I can create a simple scene for uploading if I need to.