Why the glass material in the house is always black?

[fadotian]

I have always got issues to have glass rendered as black. I made a test in the drawing by putting a piece of glass in front of the house, you could see that the glass rendered fine and transparent, but the window glass used for the house which uses exactly the same glass material, but rendered totally black! I feel at least when the sunlight shines from the front, rays of light should somehow get into the house, but it seems no light entering the house!

Anyone knows what happened? Thanks!

[ted.vitale.jdk]

Make sure you dont have a material applied to the back side face of your glass and that the glass is a physical volume. You also may need to add lights to your interior, as an un-lit interior will always look dark when contrasted by the sun.