I’ve finally got the Core Image Filter mentioned in the previous post actually to work. Credit is due to Kevin Quennesson from the Apple Quartzcomposer-dev list for his patience in explaining ROIs and DODs to be. I think I’ve got it now.
The filter is now installed in the CubeField qcFX. Not sure it speeds things up significantly, though. Flushed from this potential success, I decided to see what would happen if I replaced the Cube primitive in the FX with a Cylinder one. The results were quite interesting.