Two planes; one j3m

Hello! This picture might be useful:

I made a j3m in jMonkeyEngine, and I applied it to a box-shaped geometry with 0 depth which makes it essentially a plane (left of picture). After that, I made a plane in blender (right of picture), and I subdivided it 30 times. Then, I used a displacement modifier to give it a more realistic shape. After exporting it, I applied the same j3m as with the previous plane.

My problem is that they have very different appearances, and the plane from Blender seems to have rotated the j3m by 45 degrees. Can anyone give me some insight into this? Help is appreciated!

I guess your plane has no texture coordinates. Add them in blender (UV Map).