Here's a tutorial on how to make the basic body of a vector 3D caterpillar using interpolate.

http://kendraschaefer.com/index.php?opt ... &Itemid=15

great tut. did you try interpolating with the gradients already applied so that you don't have to go back and add them to each object created by the interpolation? just a thought.

Thanks! You know, I had the same thought right after I posted it, but I'd already written it up. Went back and tried it and got some strange results, so I figured I'd best just keep the confusion to a minimum.