Latest Railclone Beta (2.5.2b) is having problems with the random material node in Vray RT (3.30.02). Randomization looks fine in the viewport, but once rendered in RT(both CPU and CUDA) only one material id gets applied to everything except edges of array. I'm trying to use it for floorboards (same technique as tut on itoo website). As a fix I am using railclone tools to to instantiate floor, then combine into 1 object and apply a 'mat by element' modifier.