When i render glass it keeps showing up black, i have turn on and off ambient lighting (both kinds) and also have added a sun lamp but it still shows up black. Any solutions? Any help is greatly appreciated thanks!
I had this problem for a while; what I eventually figured out was going on was that I needed to increase the number of transmission samples in the Light Paths tab in the Render panel. This dictates how many transparent surfaces the light can pass through. For example, if you are rendering something through a window, it should show through. But if you then add another window in front of that one, and then another one, and so on, you'll reach a point where the glass suddenly starts showing up black. That's because the transmission samples aren't high enough, so the light isn't able to travel through so many transparent surfaces. The solution is to just increase the number of transmission samples.
Hope that helps!