Currently udon doesn't allow for you to create a cubemap rendertexture in code, because TextureDimension.Cube is needed to set up the RT, but is not exposed

More importantly, in Unity you cannot use 'blit' to paint faces onto a cubemap rendertexture, there's a unique Graphics.CopyTexture function that is allowed to edit cubemap slices, but that isn't exposed to Udon.

Please consider exposing these simple functions, or giving us other ways of creating a cubemap at runtime!