ynjh_jo, good work. Sounds also a very nice idea to do bullet holes.
This one is almost 2x faster than GeomDropShadow4, since I replaced the tree traversal by a simple grid lookup of the octreed-terrain tiles. I also added ground collisions, that contributes some ms.
To get this work correctly, you must set the tile size in the script (GRIDX and GRIDY), exactly as you used to octreefy it.
jon1.us/P3D/dropShadow/=GeomDropShadow5.zip
EDIT : added jump