Well, the task is to put grass onto a large terrain (see this thread
viewtopic.php?f=42&t=1124).
Yes, it's kinda obvious solution to use particles there, but particles from verts won't do for the purpose (no randomness in respect to surface placement), particles from mesh - too heavy on the FPS... so I went for the simple instancing using height maps (Debris) and was surprised the rotation didn't work properly... Maybe ikam could take a look into the code...
Thanks for the effort, anyway
.