I can answer your second question here. Transparancy is NOT always controled by an applied texture. Example, you can make polygons that represent window glass semi transparant by reducing the opacity of the material that is applied to the window... you need not apply a texture to it at all. You can further enhance the glass material by changing the specular values and adding reflectivity via a texture with the proper alpha values.

As to your first question, perhaps this will be of benifit.

http://forums.avsim.net/dcboard.php?az=show_topic&forum=123&topic_id=27060&mode=...

Lou

Hi,

There are a lot of tutorials about curved roofs: I retain two who are worth to read or apply.
A curved roof by the LOFT technique. There is a video tutorial available.
A second: explained on the site of Trainz Forum.
So... look via Google and you will find it.
Both are using GMAX...

Success. José.