billboarding

i’m currently using billboarding for trees and clouds in my flight simulator. The problem is that it works only in two dimensions: it is perfect for a game like Quake, but in a flight simulator, when you pass above the trees you clearly see they are quads. How is possible to overcome to this ? There are other techniques ?

Originally posted by penetrator:
i’m currently using billboarding for trees and clouds in my flight simulator. The problem is that it works only in two dimensions: it is perfect for a game like Quake, but in a flight simulator, when you pass above the trees you clearly see they are quads. How is possible to overcome to this ? There are other techniques ?

Trees - the first one solution comes to mind is to use polygonal trees. Where to get - for ex speedtree http://www.idvinc.com/
tool assist to develop the trees
we at the company are developing trees manually http://www.vrtainment.com/vrtainment_web/projects/trees.htm

clouds take a look here http://www.cs.unc.edu/~harrism/SkyWorks/

also from DX sample the idea of multiple cloud layers could be used link to DX sample is http://www.ati.com/developer/samples/clouds.html

some more on trees…
I’m not sure but maybe
Relief Tetxure Mapping see http://www.paralelo.com.br/en/portfolio/realtime3d/cg/index.php

could be used…

[This message has been edited by SergeVrt (edited 06-15-2003).]

For cheap, in-the-distance trees, try modeling the tree as three quads: an X capped with an upwards-facing quad on or near the top.

For better quality, use polygonal models, although these get expensive fast. Look into various impostor techniques (render-to-texture) to improve the rendering speed (assuming you have the texture memory).