I would be very surprised if Gelato went through OpenGL. My bet is that Gelato is using some interal APIs to talkt the GPU directly, bypassing OpenGL. After all, Gelato is not a renderer that renders its stuff entirely on the GPU but it is a renderer that uses the GPU as a part of its rendering engine, rendering other things on the CPU. That's why Gelato, unlike OpenGL, does not have texture size limits. Gelato supports a lot of features that OpenGL doesn't, like raytracing, GI or fine displacements. Also, Gelato shaders do not have size restrictions where OpenGL shaders do. "So, I wondered if CL used Maya with Gelato renderer that created an image of Snow Queen for the Poser6 Box?" No. Question: How do you say would OpenGL enhance the appearance of a rendered image? As you are an OpenGL programmer, you should be aware that OpenGL does nothing that CPU rendering wouldn't do, where there are a bunch of things that are common in production rendering (e.g. stochastic sampling for DOF and motion blur) that OpenGL can't do.