Wouldn't this be the fastest method to instanciate several similar objects?

No, it just won't work (as you have noticed). The Mesh is only one part of an Object3D. By creating a (0)-sized object, you are creating an empty object. That doesn't change when setting a mesh. To copy an object, just use the corresponding contructor in Object3D (new Object3D(oldObj)) followed by a setMesh, i.e.:

Object3D obj=<your 3ds object>;
Object3D clone=new Object3D(obj);
clone.setMesh(obj.getMesh());

or, without the constructor:

Object3D clone=obj.cloneObject();


The Object3D created by cloneObject() will already share the mesh of the cloned object.

The null pointer exception is caused by the fact that an Object3D with 0 triangles doesn't have a mesh. If it's intentionally to create such objects in your code (i suggest to use createDummyObj() instead which does exactly this, but anyway), it shouldn't be needed to share the mesh instance (even if there were one, it would be emtpy...).
However, i've added some code that should fix this albeit i don't see the point in this operation... :?:
Be aware that you can't use setMesh(<Mesh>) to use the same object with completely different meshes. setMesh() sets vertex and triangle data. It doesn't set the texturing data for example.
About the getter for the color: I've added it. Both changes can be found in this pre-release jar: http://www.jpct.net/download/jpct_108a1.jar

What a coincidence...i've just thought about that this morning. I was wondering why no one ever required this option... :wink:
The short answer is: Yes, it is possible...but not in the current version.
The long answer is: The OpenGL renderer tries to mimic the behaviour of the software renderer. The software renderer can't go below ~50% (in fact it's 70% IIRC) for performance reasons. I think that i'll add a setting to Config (glTransparencyOffset or similar) that will allow to adjust the transparency formula for OpenGL only. This means that you'll have to adjust your transparency values when modifying this setting to get the same results as before. But that shouldn't be too much of a problem. I hope to add this on monday.

:shock:  :shock: Very cool...

It's there! It's very similar to the pre-release versions that i've posted in some threads. Anyway, here are the changes:

http://www.jpct.net/changes.html

Have fun!

btw, sometimes forum engine doesnt notify about replies

Works for me all the time...couldn't possibly be your spam filter or something?

You can assign different textures to an Object3D with either the 3DS loader (as you you've already mentioned) or with the addTriangle(...)-method in Object3D. Because you are writing a loader, i assume that you are already using one of those. Simply change to one with a textureID as parameter and you should be fine.