Has anyone on this list ever tried using ODE for 'the wind in the trees'? Or... know of any related projects that do? An example of a commercial package would be http://www.idvinc.com/html/speedtreert.htm Cheers Garry -- Garry Keltie garrydotkeltieATrmit.edu.au Interactive Information Institute RMIT .. .... .. - / .... .- .--. .--. . -. . -..