Hi ,

I am working on a virtual production setup with Aximmetry and an external hardware keyer, and I would like to ask about the official/recommended way to output a key signal from Aximmetry in the “Aximmetry First” workflow.

I have read the official documentation here:https://aximmetry.com/learn/virtual-production-workflow/green-screen-production/keying/using-aximmetry-with-an-external-keyer/

Our current setup uses the first workflow: the external keyer sends Fill and Key/Matte into Aximmetry, and Aximmetry does the final composite. This works, but the total system latency is relatively high.

We are considering the second workflow to reduce latency, where the external keyer performs the final composite. However, we also need some virtual foreground / AR elements generated by Aximmetry to appear in front of the presenter. Ideally, Aximmetry would output these foreground elements as a Fill + Key pair, similar to a broadcast graphics system.

Questions:

1. Can Aximmetry output a separate SDI/NDI Fill + Key pair in this workflow?
2. If yes, how should this be configured in Aximmetry?
3. In the UE scene, how should we mark which elements should appear in the Key signal / foreground layer?
   For example, should we use tags, custom render layers, stencil, or another Aximmetry-supported method?
4. Is there any recommended official compound or workflow for this setup?

The goal is to keep the low-latency benefit of the external keyer doing the final composite, while still allowing Aximmetry-generated foreground/AR objects to be keyed over the presenter.

Thanks.