View Full Version : Global Illumin. for an interior

05 May 2006, 04:38 PM
Yea, I am working on my first GI interior, a full interior. I am using a sky map because the front of the store is glass. I have found it very strong as you can see (it set to .1 and I still have blowout). Why does the sky cause such a hard shadow?

I have 3 point lights in the middle of the room and they are set at .2 or .3 intensity and that is it. All 3 point lights are set to "normal" for their GI setting.

Any advice.

05 May 2006, 04:56 PM
No way is that skymap causing that hard shadow. There must be another light-source you forgot to switch off.

05 May 2006, 05:10 PM

My they are interesting... if slightly bizzare GI settings you have there... 3 secondary rays?

The shadows are directional, which means you have a 'sun' causing them. The skylight (if thats what you mean by skymap) causes shadows similar (but not the same as) the occlusion shader.

Also, try 2 bounces for reverse illumination.
Good start though!

05 May 2006, 05:39 PM
Yup, there is light outside that has raytraced shadow on it. Doah... I will do some without that guy so bright. Thanx.


05 May 2006, 01:57 PM

I'm not sure why you used the settings you did. My own experience with GI suggests that a sky light of 0.14 isn't going to contribute enough to even be noticeable--same with the 3 bounces and the (?) 3 secondary rays. All that stuff is basically just jacking up your render time.

My advice would be to do Phong renders with no GI until you're pretty close to what you want, then start adding in GI effects as necessary. It's a method that works pretty well for me.


05 May 2006, 02:00 PM
Steven, there was this thread last march with great information about GI.

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