no lights or Reflection from loaded Object

Hello,

i used the xith3D ASE loader to load some Files. The problem is that if i use lights in my scene, they do not have any effect.
The surfaces are just flat with no shadows or different illumination. It seems that the adding of a light does not have any effect on my objects. I know that for simple objects genereated in my Branchgroup i have to set a material to make them affected by light. Because i have large models with up to a few Megs i don’t want to parse them afterwards to add materials. Does anyone has experience with loading models (or exporting from 3DStudio) to make them work with light in the scene?

Thanks in advance,
Chris