Set scene material def

Is there a way to set material def to unshaded for my entire scene ? I made the scene in blender and exported with orgexml . I already know how to set material def for materials loaded dynamicly but dont see anything about changing it for imported textures. I know i could do this if i converted all materials to .jm3’s but i cant find where the materials are in the scene explorer .

Any help is much appreciated, thanks!

Select a geometry. Not a node but a geometry. Then in properties pane (top right) you have a material setting. You can even export the current material from there.