I’m exploring the possibilities of OSL shaders with Arnold Renderer.
These are shaders often written as small helpers across different platforms. It works with Vray, Arnold Renderer, Render Man, Octane and Blender.
In this case you can create a WindowBox, Interior Mapping or Parallax Mapping really fast. You just follow the instructions to create a room with 5 sides a middle ground and front (curtain), and the OSL file it self is added to your c4dtoa shader folder.
Download it for free here