Mesh gets light only from 1 direction

EDIT: For the purpose of my game, this is no longer useful since I have changed to another model which is unshaded.

So this is no longer a problem and I won’t put effort into investigating it.

For the purpose of the discussion, it may still be worth figuring out what’s wrong, but I suspect we won’t get there.

Thanks for your help everyone who tried.

/Edit

This plant model I made only seems to catch light from behind. In JME it displays almost black but you can see some green parts (the stalk) through the leaves.

I think I did something wrong in Blender, I made the stalk from a cone and extruding it, then built 1 leaf by extruding an edge, then duplicated that and made 6 of them attach to different places. Since the stalk catches light but not the leaves… what’s wrong? I think I applied material on the stalk before making the first leaf.

In blender F12 renders fine, but the p key (game engine someone said) will display only the stalk, not the leaves.

No problem with the animation as you can see (in jme sceneexplorer), but only light from 1 direction.

edit (wrong video )

Try adding an ambient light?

Materials imported from blender seem to have problems with ambient lights.

If you have one added in the scene try creating a new material to use and applying that to the plant model.

I should have mentioned the context. Every model in the game was made in blender and this happens to none of the others. I don’t see any obvious difference in how I made this one from the others.

I’m not sure what type of lights we have since someone else is specialized in that part. We may or may not have ambient lighting in the current build.

Latest gameplay video (the plants are visible but almost black, since they don’t reflect light).

Have you tried using the TangentBinormal generator?

I edited my original post but posting here too for clarity's sake. 

EDIT:
For the purpose of my game, this is no longer useful since I have changed to another model which is unshaded.

So this is no longer a problem and I won’t put effort into investigating it.

For the purpose of the discussion, it may still be worth figuring out what’s wrong, but I suspect we won’t get there.

Thanks for your help everyone who tried.

/Edit