Hey Darcey, Sorry for not replying earlier, I was on the move and quite busy!
These are really cool. I would suggest one thing: To compensate the sorting issues, you could set a z-offset or a front layer sprite render session for the non-extruded flat part of the text, hence always ensuring that that part is in front of the extruded bit. Of course, this would work on the assumption that the camera does not look at the text from behind. Cheers, li
