Apply Camera Mask to Skybox

I could need some help with the camera masking shown in this example project:

I used the masking to render some geometry as part of my ui. Works perfectly fine so far, expect, I cannot render the hdr environment on my main camera anymore :>
Seems like the skybox object does not have any mask property. Is there anyway to tell the skybox, that it should render on a specific camera only?

Edit: Thought in the meantime about a small workaround, which is working although not ideal.

You can avoid that the geometry in the ui layer is affected by the skybox, by just setting the “useSkybox” parameter of their materials to false. But that isnt helping to render the skybox on the main camera (the one with the color buffer cleared). So I created a “fake” skybox with a bunch of planes, which is assigned to the render layer of the main camera. You just have to change the texture settings of the imported skybox sides to “Clamp” and assign a unique material for each plane.

That works, although I am not too happy yet, as it requires some additional setup & I miss the mipmap option of the cubemap. Tough I could probably just build a script for that as well.

@vaios @max @dave @will
Dunno who is working on this part of the engine, but any chance a masking option gets added to the skybox?