LC #42 Pipers Alley

View Full Version : GI and FG together creates disco ball spots

04-18-2006, 12:38 PM

I'm playing around with GI and FG. I think I almost got it now, but I have one problem. I keep getting these big spots. How ever as funky as it migth be, it's not the look I'm going for. The only way I can smoth them out is by using ALOT of Final Gather rays, but that will increase the rendertime ALOT!

Is there any other way to get rid of these spots?

My settings:

With FG no GI:

With GI no FG:

Both, now all the sudden I get big nasty spots all over:

The same, but with Final Gather rayes set to 1000:

Hope anybody can help.

: ) Jakob

04-18-2006, 12:50 PM
increase the FG filter to 1 or, if the spots are still there, set it to 2.


04-18-2006, 01:00 PM
Thanks alot Yashu. A very small thing, but yet important :)

04-18-2006, 01:17 PM
hi. isnt` that a photon radius problem also?

04-18-2006, 06:14 PM
Don't know. It seems like it solved the problem perfectly. To be hornest, I hardly know what I'm doing, I'm just clicking a button here and there ;)

04-19-2006, 05:42 AM
Hmmmm spots like that created from Final Gather are usually from using a HDRI.
But maybe somthing is clashing between Gi and FG.

And by the way if you are ever using a HDRI and get spots...adjusting the Filter in the FG menu section clears the spots, but also totaly take out alot of depth and contrast in the lighting.

Here is a link that is killer for FG stuff

Hope it helps:buttrock:

04-19-2006, 06:02 AM
hey ! Whats up !!

Those spots are due to the photon radius you should do incremental adjustement till they go !! Also try to raise i little the photon number !!

See ya !! Hope it help !!

PS: Try not just to press botton try to understand whats happening

04-19-2006, 07:11 AM
AlpahKaneda > No HDRI, but I will remember that. Thanks for the link! It rocks! :buttrock:

zhaor > That radius you and hitori is talking about, is that the photon volume radius? Is there any thumb rules on how big the radius should be?

: ) Jakob

04-20-2006, 01:37 AM
Nop the radius im talking bout its the global illumination radius its on the render globals window under global illumination. An i dont think theres any rules cause its depends of the size of the scene, try to do incremental changes till its start to work better also try adjusting the global illumination accurancy !!

Hope its help !!


04-21-2006, 03:41 AM
-Those kind of spots are generally related to photons.

-don't tweak final gather ( it will increase rendre time).
-increasing the photon radius should solve th problem.
-Now, if the problem remains, then it's a number problem! becose you are asking a small number of photons to illuminate the hole space, so try increasing this number and it should work just fine!

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04-21-2006, 03:41 AM
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