I am working on (or rather designing without access to Blender) a material setup to make a texture tileable (see here: http://blenderartists.org/forum/showthread.php?372297-Addon-WIP-Automatic-materials-from-textures-in-Cycles/page3). I basically need to mix a texture with a copy of itself moved slightly. (The factor comes from a texture) It can't be done deterministically without having two image nodes, because I need two separate vectors to have two separate images. What I would like to do is to have a per-ray random number, that will let me alternate between the two vectors, thus removing the need to have two images (it is not a huge burden in theory, but when I need to have all texture maps doubled, it becomes a complicating factor.). Does Blender have such a feature?