[sysrpl]

It can be incorporated into a 3D scene as long as you can make a square billboard . You may have problems with clipping that' you need to address manually, but it might be worth it as you can get better visuals, assuming you are trying to render spheres.

As far as I know there shouldn't be any distortion issues. A sphere will always look like a circle from any perspective. Well that is unless it's really really big or your are really really tiny and you give the size difference you are relatively close to its surface. At that perspective it just look like a flat plane.

[rzzzt]

Parent may or may not know this, but "billboards" are textured quads that always face the camera in a 3D scene. Trees and foliage are things that usually turn into billboards in a typical game if they are far away.