Ok solved issue after alot of time trying. Dont forget to use OmsiXconverter from Blender.
1, What any1 needs to do is in Blender: Duplicate the object move it to another 2nd layer.
2, Now in editor mode select all and deselect the item or items(holding shift + C) you want to create glass on/transparent.
3, Now goto material button (red/black icon), and goto e.g where their is glass texture in sceneryobject one, Im using from Rumpelhans_Objekte and in texture mode add glass texture from image and browse to that file (e.g I changed it to glass.dds to make it easier.).
4, Now apply to object/s and export that object as Glass and should have Glass.o3d add that to object folder.
As The_Growl said add in object mode add Solidify I add -0.300 for thickness.
Back to original object on 1st layer.
1, Now select all item/s that you selected (from above) and delete them.
2, Now export that object to same folder.
3, Open sco add this e.g.
[mesh]
Glass.o3d
[matl]
Glass.dds
0
[matl_alpha]
2
4, Make sure to have Glass.dds in the texture folder too.
Pic Layer 1 (Original)
View attachment 13403
Layer 2
View attachment 13404
Hope this helps any1.