This was determined using FMS bete 8.5. It will probably work for all previous versions :
Trees are usually defined as two panels at right angles to each other, intersecting at their vertical centers. They are normally made with two sides to each 2D panel because a single side can be seen from only one direction
If you use "CULL OFF, a single sided panel can be seen from both sides. This means that you can define a tree by only representing two single sided panels.
The lighting for the two panels will be the same on both sides, so it will depend on whether you use clockwise or counterclockwise coordinates.
The example below uses the "Tree.bmp" from the FMS "World" scn.
If this is inserted in the middle of a .scn program, make sure that you use "CULL ON" at the end of the trees or you may get strange effects with the objects that follow..
CULL OFF
POSITION -12 -24 2.9
TEXTURE TREE TRANSPARENT
256 0 -6 0 11
0 0 6 0 11
0 256 6 0 0
256 256 -6 0 0
256 256 0 -6 0
0 256 0 6 0
0 0 0 6 11
256 0 0 -6 11