Hi,
I'm french (and noob), sorry for my english.
I tried to import xfrog plants (some tests here: http://web.inf.tu-dresden.de/ST2/cg/downloads/publicplants/) in my JME scene in .obj format, so I use JME ojb loader (like in tests packages), but I always encounter the same bug:
java.lang.NullPointerException
at com.jme.util.TextureManager.loadImage(Unknown Source)
at com.jme.util.TextureManager.loadImage(Unknown Source)
at com.jme.util.TextureManager.loadTexture(Unknown Source)
at com.jme.util.TextureManager.loadTexture(Unknown Source)
at com.jmex.model.XMLparser.JmeBinaryReader.buildTexture(Unknown Source)
at com.jmex.model.XMLparser.JmeBinaryReader.readBegining(Unknown Source)
at com.jmex.model.XMLparser.JmeBinaryReader.loadBinaryFormat(Unknown Source)
at com.jmex.model.XMLparser.JmeBinaryReader.loadBinaryFormat(Unknown Source)
I don't know if it's a JME problem or Xfog .obj format.
My code (very basic):
private void loadObj() {
ObjToJme converter=new ObjToJme();
try {
URL objFile=Model.class.getClassLoader().getResource("data/model/mymodel.obj");
URL texDir=Model.class.getClassLoader().getResource("data/model/");
converter.setProperty("mtllib",objFile);
ByteArrayOutputStream BO=new ByteArrayOutputStream();
converter.convert(objFile.openStream(),BO);
JmeBinaryReader jbr=new JmeBinaryReader();
jbr.setProperty("texurl",texDir);
Node r=jbr.loadBinaryFormat(new ByteArrayInputStream(BO.toByteArray())); <-- here the line raising the exception
r.setLocalScale(10f);
attachChild®;
} catch (IOException e) {
e.printStackTrace();
}
}
When I import these models with Blender or 3DSMax, it works correctly, if I re-export them without textures, it works properly in JME, so I think textures loading is the problem.
Thanks for any help.
Resolved
I found the problem: textures were in ".tif" format, it doesn't seem to work with ImageIO.read(…)
With .png no problems anymore.
JME is a great engine, thanks for your job.
Congrats on getting it working yourself. 
darkfrog