Does anyone know how to create a billboard in OpenGL ES for the iPhone? I been looking for a tutorial but they seem non existent. I know how to create normal objects etc and apply a texture to it, but am looking to have walls with photos on them in my game.
Update:
So what I am looking for is the best way to put a photo quality image that could be any size in to 3D world. I believe textures have to be certain sizes etc (128 * 128, 256 * 256 or 128 * 256 (are they square numbers?). I have seen examples of this in PhotoCastle3D and 3D Gallery)
2nd Part to this would be displaying this as a billboard that always face forward, good example would be for trees or bushes in a game. Thank you all for some good info, will go investigating.
If the billboard is not a component of the texture on the wall, but rather a separate object in the 3d view that is placed very closely to the wall, check out polygon offset. It’s should be available in opengl-es. http://www.opengl.org/sdk/docs/man/xhtml/glPolygonOffset.xml
Basically its a quick way to resolve z-fighting between polygons, if their vertices both try to occupy the same place in the z buffer.