XM Magdalena 3D print, GGeorgy (3D)
LC #42 Pipers Alley

View Full Version : Global Illumin. for an interior

05-25-2006, 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.

05-25-2006, 04:56 PM
No way is that skymap causing that hard shadow. There must be another light-source you forgot to switch off.

05-25-2006, 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!

05-25-2006, 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.


05-26-2006, 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.


05-26-2006, 02:00 PM
Steven, there was this thread last march with great information about GI.

CGTalk Moderation
05-26-2006, 02:00 PM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.