USD lights ShaderTweaks

[Riccardo Cecchinato]

Hello dear Gaffer devs,

On Gaffer 1.5.2 it seems like the ShaderTweaks over USD lights is limited to few parameters, while many others that exists in the light shader are not selectable/tweakable.

For example, all the (Arnold) contributions in "refine" are not editable.

In my case I need to override/kill the volumetric contribution of an USD light downstream in my graph, but I am not able to do it through the ShaderTweaks node.

Is there any workaround for this? Or am I doing something wrong?

Thanks as usual for your help!

Riccardo

[Sachin Shrestha]

Arnold exporters don't export parameters if their values have not changed from the defaults. And if they don't exist in the exported usd files, then I think the tweak node is unable to display them in the node's UI. However, you can create them yourself using the "Create" mode and override as shown in the attached snapshot of a usd file from maya in gaffer. You need to ensure that you are providing the correct parameter names and types for any parameter that you want to override.

Hope this helps!

-Sachin

[Riccardo Cecchinato]

Sachin!

That's it! Thanks for the precious information!

All the best,

Riccardo