Hi there,
I am creating a plant to be used in the blender game engine, it will be static so I want to bake its lighting with Cycles render. The leaves will be created using single planes or strips of polygons, and textured using different images on each side (this can be achieved using a back/front face output in one of Cycles’ nodes) but I do not know if it would be possible to bake this down for using in the game engine, could anybody help?
For the final object don’t use back faces.
Before baking, select the verts of the leaves you want to be double sided duplicate them and flip the normals. You’ll need different UV co ordinates for the leaf backs, but you only need to do this for the leaves, not the stem or the pot if it has one.
Thanks very much, but I wouldn’t have thought you’d need different UVs anyway, as long as the textures lined up.
If two faces share the same UV coordinates when you bake textures Blender will try to bake both on top of each other, it results in messed up shading. it’s not a problem if you’re just baking textures, but any lit mesh will have problems. Just select the back faces and move them to an empty area of the UV map. Then bake away. 
The other think you can do if you don’t care too much about shading is just bake single sided and then set double sided ont he final object.