Transparent Glass

[maurorog]

The glass of a window or the glass of a frame must be a rectangle in two dimensions or in three dimensions ?
And in case it is a rectangle in two dimensions, the material should only be applied to one face or both?

Thanks and sorry for the question ...

[vladimir.nedev]

It should be 3-dimensional, i.e have thickness, so the rays get refracted twice - once entering and once leaving the glass. Otherwise the refractions will look wrong.
For even better results, there should be two 3d planes with space between them, as usually windows have two glass sheets with air between them.

Greetings,
Vladimir Nedev