Multi/Sub-object with cryptomatte?

[funonfun]

Hello Chaos Group

The new feature cryptomatte is awesome!!

but i got a little problem

i set a simple scene with a box object

Apply a multi/sub-object material to the box object (3 ids)and render

cryptomatte render element result is only one id matte

even i tried different cryptomatte id types
i still got same result

Is there a way to use Multi/Sub-object material with cryptomatte and get correct id mattes?

[vlado]

Right now the Cryptomatte render element only sees the top-most material name. It is on my "to do" list to make it see into multi/sub-object materials, but it requires me to break the V-Ray SDK.

Best regards,
Vlado

[super gnu]

that sounds nasty. would you use a hammer?

[vlado]

would you use a hammer?

Just a small one

Best regards,
Vlado

[funonfun]

Thank you for your prompt reply vlado

If the cryptomatte can be work with multi/sub-object materials
it is really help me and save my lots id matte elements workflow time

[hypotheticalinc]

How is the progress on multi-materials and Cryptomatte going? I just tried the latest Vray Next demo and it doesn't look like it's working, though I may be misusing it. It sounds like there's a variation (maybe even a more complicated one?) in Maya right now: https://forums.chaosgroup.com/forum/...ne-nodes/page2

Any news?

[Vizioen]

Would be nice to have this supported, pretty please? Just tested the new EXR.IO 2.0 photoshop plugin and it's awesome but multisub object materials aren't supported and we have a lot of those > Forest pack etc.

[Moriah]

+1 on these, since forest pack can only deal with attached geos (no support for groups), our only choice is to merge the objects and use multi sub, so in the end everything with forest can't be used with crypto.

[armilla]

Has there been any progress on this by any chance?

[natec]

Any updates on this issue, just ran into the same problem with a lot of game assets. Took quite awhile to work around.

[kimgar]

I ran into this too now, with vray 5.
Can't really detach objects to get the cryptomatte id's either, as it messes up normals and smoothing.
Only workaround I can think of is using VRaymtlID element, but this is limited to 15 id's and I've got hundreds...

Anyone have other workarounds?

[zpavlov]

Yes, this a real bummer. I really hoped for this feature in Vray 5.

There is a modifier written by Clovis Gay (kinematic lab), that can isolate model elements based on their material ID. So if you have 10 IDs in your model, for example, you can copy that model ten times and put that modifier and isolate the desired ID.

https://gyazo.com/b3fbb4151c47c5bf64c50344cc72f1a5

I imagine Vray would be able to pick it as different objects and write a usable cryptomatte element.
However, I can imagine how time (and memory) consuming that would be if you have an object with 100+ IDs. If there is some way for this to happen internally, on render time, it would be a nice workaround i think. Otherwise, vray cryptomattes are pretty gimmicky at the moment.

[trick_979]

Hi guys I am using VrayNext 4.3 and on GPU with bucket mode and CryptoMatte is working with a Multi Sub-Object material.

[White Wizard]

Hi guys I am using VrayNext 4.3 and on GPU with bucket mode and CryptoMatte is working with a Multi Sub-Object material.

I can't seem to get this to work. Did you have to do anything extra to allow it to work with Multi-Subobject materials?

[trick_979]

Hi guys,
Here is a video how i did it, nothing special - just set to vray gpu and Bucket mode: