Trees, Grass and Shadows

[Crisium]

Hi users,

I have question about rendering shadows on grass billboards. This is not a question about anything missing or not working in OpenSceneGraph, but a question how to solve a problem with shadows and grass.

The problem is the grass are created using a shader that creates billboard instances, so all grass you see in the video are billboards. When the shadowmap is applied to the grass billboard I get streaks at certain camera angles. Does anyone know how to fix this problem so the shadows looks more natural on a grass billboard.

Here is the video:
http://www.youtube.com/watch?v=iuEVJ-2xQO0

regards,
Peter Wraae Marino

ps: see video in HQ