Since upgrade to 3.1 beta I have a lot of errors in old Lighting materials:
java.io.IOException: The material parameter: Minnaert is undefined.
What has been changed in Lighting MaterialDef?
Ok, I found out myself
This will make the old metarial need upgraded. Should there be a warning somewhere in the doc?
You can open j3m files in the SDK and make a change, then the j3m will be rewritten without these parameters.
Just remove those parameters from the J3M files, they are no longer used.