Hi, I wanted to ask if such a thing is possible: Is it possible to use billboards instead of models for stationary objects in the distance. For example things such as buildings and trees would appear as 3D models when in range but once in the distance, a billboard is used. Each object would have 8 different billboard pictures taken from 8 different angles. Based on the player''s view, the correct version of the billboard is displayed in place of the 3d model. Since there are 8 different billboards, it would mean that the most the billboard would be tilted is 22.5 degrees. A billboard texture I believe holds up quite well at 22.5 degrees and it shouldn''t be noticable. Secondly, since they are in the distance, low resolution billboard textures would be enough and this means that not too much system resources are used. Finally, a player would turn around something nearby but when a building is far in the distance, a player wouldn''t be able to circle around the building to notice a billboard switch. Through this method, by having objects nearby appear as models and having objects in distance appear as billboards, one could have cities with buildings far into the distance or forests with trees into the horizon while maintaining low polycounts. Is such a method possible? Can anyone find a flaw or point out the problems with this? I would appreciate any comments, Thanks in advance

I think your getting confused with what a billboard should actually be used for. Billboarding is where you have a poly/quad which is always facing the camera ie always visible even when you rotate.

In most games you find that trees are represented by two textured quads which cross each other at 90deg (creating an X from above).

You shouldn''t really use models for tree''s in games as it is too inefficient.

However things such as buildings this idea would work although I don''t know how well. In the industry the favoured approach is to use LOD (Levels Of Detail) and have lower poly models as you get further away.

Hope this helps in some way.

Phill Sampson
Physics & AI Programmer
Eutechnyx LTD
http://www.eutechnyx.com
http://www.liquidnrg.co.uk

Thanks alot for the reply. I guess I didn''t mean billboard then. I meant displaying a simple square surface with a picture of the building on it (picture based on angle of view).

Are there any big problems anyone can point out to me as to why it wouldn''t work?

Thanks again

quote:Original post by YourOtherLeft
Billboarding is where you have a poly/quad which is always facing the camera ie always visible even when you rotate.

1) Yes original term 'billboarding' means fragment that faces
always to the camera. But nowadays many programmer/artist ppl
calls only null-fragments (null pixels removed) as well billboards althought they're static and don't face to the any camera direction never. For example i like to call them that wway.

quote:Original post by YourOtherLeft
You shouldn't really use models for tree's in games as it is too inefficient.

2) Not true. Mesh trees are awesome and not inefficient always.
In my experience, combined mesh tree body + static 'billboard' leafs are kewl combination and not so inefficient.




[edited by - rickpeek on March 23, 2002 4:06:07 AM]

quote:Original post by Cameron
Is such a method possible? Can anyone find a flaw or point out the problems with this?

A similar method is discussed in the book game programming gems 2. Basically you render to texture (and update as needed, but not every frame) and stick the texture on a quad.