Hi, I just started looking at JME for some weekend Java fun, but immediately ran into a problem.
I've decided to use Blender as my modeling tool, and started out testing various tool paths to get my 3D data into JME. So far, the only format I've had any success with is collada, but mirrored objects imports with inverted normals.
Even if I re-calc them i Blender (CTRL+N), they still show up wrong. If I re-import the .dae file in Blender, it looks fine (although faces are double-sided). JME, btw., also renders faces double sided, but maybe this info is not in the .dae file?
You can test this easily - using the default scene in Blender, export to collada, load in jME. Mirror on Z-axis, and export/test again. You'll notice that lighting is now reversed.
I remember having a similar issue when working with Max6 and my own XML format some years ago, but hacked my way around it - I was kind of hoping that I didn't have to with jME/Blender ;), and that I've simply missed something obvious.
Fixed it :D. In case anyone else run in to the same issue:
I Loaded the .dae file in the text editor and found that it implements mirroring by negative scaling - applying the transformation in Blender (before re-calculating normals) fixed the problem.
(I.e. in object mode CTRL+A to apply transformations, TAB to go to edit mode, CTRL+N to fix normals)
Thanks for posting your findings, I bet that will help someone else!