Cryptomatte with subobjects, by material id?

V-Ray V-Ray for 3ds Max General
1

Hi guys,

We’re using Cryptomatte a lot, but there’s a few gotchas. The thing we’re missing most is defining masks per object/material id, and not just objects. Imagine a cached building destruction simulation. You have bricks, wood, glass, etc, and this is loaded in a single Alembic loader. This is giving us just a single mask in Cryptomatte, and we need masks per material - any way to pull that one off?

Thanks!

2

Request added :slight_smile:

3

Would be great to have some mechanism to get notified about how these things go. We do keep an eye on changelogs, but still :slight_smile:

4

We are trying to post in the respective thread when the feature is added / the bug is fixed. The ID for this one is VMAX-8524. The alternative for you is to come to the office to say “Hi” with some beers.

5

Ok, that should work, thanks

6

Hi, any update on this?

7

Yes, this is already in the nightly builds; if you can check it out and let us know if it works fine, it will be great.

Best regards,
Vlado

8

Great, I don’t have access to the nightly currently so I’m going to write to support for that. Thanks Vlado!

9

I wonder will this behave with forestpack too? Jumping in on this one also!

10

If you don’t want to wait for the official Hotfix 1 (which should be later this week), you can download the latest stable build from here - Chaos

11

Hi, I’m using the latest nightly and there is no think like MatID in the cryptomatte. Should I set it as a node user property or there is something I’m missing?
Thanks!

12

Can you share a simple scene where this is not working?

13

Sure, here is a teapot with Vraymultisub. Thanks
teapot_matid_Cryptomatte.zip (64.2 KB)

14

I noticed that what it does is use the material name, so it means that it needs to be set in the cryptomatte like that but also, it won’t work with a Vraymultisub, is that correct?

15

Yes, the mode in the Cryptomatte is called “node material name” so you need separate sub-materials.

16

hm.. so.. sub-materials are automatically separated? Any more controls that I’m not aware of?

17

Yes, they are separated if the ID type is “Node material name”, what kind of additional control do you need?