Areaportals and glass/clip brushes and props

[Cookie^]

I have been wondering for a while, does glass and brushes like playerclip and invisible count as openings for areaportals?
If I have a room with 2 doors and 1 window, does the window also require to have an areaportal?
Also, if I place an areaportal but there is a prop inside the brush, will it crash my map?

 

[Crash]

They most definitely count as an opening and need to be sealed with an area portal. Props inside doesn't affect anything.

 

[henke37]

Glass is a transparent material. Brushes with even just one transparent material don't seal anything. Invisible and clip are tool materials that don't seal either.

 

[A Boojum Snark]

Area sealing is exactly the same rules as world sealing.
...aside from the fact area portals don't seal the world