[gpz]

At first look I also see like if the side wall of the coach was totally opaque, and a blended window was drawn onto it. I don't know how it could work in MSTS, but I think this approach will never work in OR. In OR windows must be cut out on the solid side wall, either with 1-bit alpha pixels or geometry.

[Monty]

Peter If you look at the Super Chief set from 3dtrains who also did the Cal Zephyr set that does not show transparent windows you will see that the same approach was taken with solid walls with the window on top yet it seems to work ok in OR and MSTS. Look at the observation car or dormitory lounge of the Super Chief set and they seem to work ok in OR. I have looked at both sets of cars and cannot see what is different between Super Chief and Cal Zephyrs car, why one set is fine in OR and the other not.

[James Ross]

If I understand correctly, that the model has a solid base and then transparent windows placed on top (with no cut-outs), it's never going to work in OR (and anything that does is a pure fluke that might change at any time). It might work in MSTS because it has a predictable order of drawing elements of a model and if you draw the transparent windows first it'll probably work. (The same order might work in OR but we have a much less predictable draw order for a single model (because everything gets shuffled around and optimised).

[Monty]

James You understood correctly. Thanks for your explanation. I guess it is just something I have to live with. While I am here thanks to yourself and all the team for the great effort with OR. It has beamed new life into train sim for me Cheers