using sketchup model in vizard

[Oshimeier]

HI,

We build some models using sketchup and outport as obj file. When we add the obj format file into vizard, some of the surfaces turned black from certain perspective. But when we moved to another perspective, then it turns to be fine.
However, when we use 3ds MAX to build the model and export it in OSGB format, no such an issue.

Does it mean that model built in sketchup is not well supported in Vizard?
Furthermore, is there any other solution to fix this problem other than giving up sketchup?

Thanks