Cryptomatte for Arnold GPU

[am_wilkins]

Good day,

We're currently evaluating a switch to Arnold GPU from CPU for upcoming productions.

However, we are evaluating Arnold VS some other engines alongside this.

There is a good chance it may boil down to 1-2 currently missing features in Arnold GPU that could be make or break for us.

1. Cryptomatte AOV.
2. Shadowmatte

It's been a while since new posts were made about these features, so I'm following up.

Can you reveal any ETA for the inclusion of at least Cryptomatte in Arnold GPU?

all the best,

amwilkins

[Stephen.Blair]

No, I'm sorry, but I cannot give out ETAs or promises for new features. Cryptomatte for Arnold GPU is certainly something we want and plan to do.

[am_wilkins]

Okay, thanks for the reply Stephen. Appreciated.

I won't hold out for it in the next 1-2 years then.

I'm sad this is the case however, been requests since at least 2019 on this forum.
Is there any reason why such an important feature like Cryptomatte has been so de-prioritized?

Redshift, Karma, hell... even Unreal all has this feature.

all the best,

amwilkins

[Stephen.Blair]

---

@am_wilkins wrote:

Okay, thanks for the reply Stephen. Appreciated.

I won't hold out for it in the next 1-2 years then.

I'm sad this is the case however, been requests since at least 2019 on this forum.
Is there any reason why such an important feature like Cryptomatte has been so de-prioritized?

Redshift, Karma, hell... even Unreal all has this feature.

all the best,

amwilkins

---

If it happens I would expect sooner that 2 years.
It's not deprioritized, it's just not as simple as all that in the Optix rendering framework, as I understand it. Along the same lines, there's no public Arnold GPU API for custom shaders or other plugins (and Cryptomatte is a bunch of custom plugins).

[am_wilkins]

Okay, thanks for the info Stephen.
We'll keep on holding out for this feature.

[am_wilkins · Accepted solution]

For those who may stumble on this post.

Looks like exciting times ahead, keen to try it out:
https://help.autodesk.com/view/ARNOL/ENU/?guid=arnold_core_7350_html

Thanks to the Arnold team.

"Optimized Cryptomatte and GPU support: Arnold now has an internal implementation of Cryptomatte that adds support for GPUs and improves performance on CPU. Cryptomatte now consumes less memory for samples, making it easier to use higher AA settings, progressive rendering, and adaptive rendering (when properly used with FIS). In a simple scene rendered at 640x480 resolution with three cryptomattes the below table shows improvements in peak memory. (ARNOLD-11042)"

amwilkins

[AlphaMax9]

Has anyone successfully configured Cryptomatte to work with GPU in Max 2026?

While CPU rendering works fine, GPU rendering produces a red output and doesn't function properly. Are there specific settings needed to make the GPU version work?

 CPUGPU