Note that if i export the file from blender into .obj+.mtl and then import these files into jme, it’s working (but then i lost the name of the node i put in blender).
Important thing : this bug was not here before. I realized that my model is twice too big, then i added some parent link between my node (to attach them and resize them). It worked for blender (resize ok) but then when i import it into jme i lost the 2 turret and the thing above (and get a bound box of 800, which is impossible and not there in the .obj).
I can provide the .j3o and the .obj if needed.
P.S.: i need to have different objects in the model, because i want to rotate them individually to aim. I think i could try this with bones but it could be an overkill and i don’t know how to use bones.
I succeed to have what i want (the turret with the correct size and rotational things) and i found more information about the bug.
it seems that every parent relation between object make the bounding box bigger than it should be. I just removed all the relation ship things (and export to collada then import it in blender - otherwise it seems that the .blend file stored some information about precedent relations) and added just one relation ship and the bounded box was bigger than the actual model (not as big as before however - but, remember, with only one parent relation).
when i (the camera) am inside the bounding box, shooters with the parent relation just diseappear (cull, i guess).
So, with many parent relation the bounding box is huge and some element are never visible (because the camera is either too close and inside the bounding box or the camera is too far to see details).
As i said, i played with the origin of sub components and i can rotate them like i want to. It’s not perfect, and i think i am not the only one who is playing with the parent relation, so if it’s really a bug, it could be interesting to find out why it happens and/or document it. But i don’t neeeeeeed it :amused: i can workaround it (in the worst case : with an xml file to describe the relationship between elements).
I managed to workaround it with applying location, rotation and scale to all your models.
But it is indeed a bug so I will try to fix it.
Thanks a lot for a simple model for testing and for the hint about bounding box, maybe this is indeed a problem