View Full Version : Final Gather problem

12 December 2009, 10:30 PM

Hi, I've been having a problem with render time. I'm using GI and FG and noticed that when I turn off FG I can render the scene in 8 minutes (only one light). When I turn on FG the same scene (only one light) takes 40 minutes. FG has the default settings. When I add three lights the render takes over 2 hours. I created a diagnose render but still can't find a solution. When I use GI and FG together I noticed that the GI part computes in a few minutes and then once it gets to FG the render just drags. The scene renders in about 3 to 4 minutes without any lighting.... I was hoping that I might get some suggestions to a solution.


12 December 2009, 10:55 PM
well, the presample density is very hig as you see on your image diagnostic, but more information for a light, if is portal light and if you use sun&sky or any preset particular like arealight setting on the window.
please more infos.

12 December 2009, 01:13 AM


Thanks for the reply ytsejam1976,

I have an area light and physical sun and sky light. The pix show my settings starting with the area light. If I can provide more info please let me know.


12 December 2009, 08:29 AM
You don't able to use a portal light on arealight as custom light shaders? Why if you use PhisicalSun&Sky, the direct is on raytrcing setting like a old metods and if you show the output progressive shure that the sun photons stored well?
Anyway with sun&sky you use a portal light that redirect the environment rays on your room and the rays don't come outroom, this help your render. Another is, try to use a slower rays and Presample density to 0.100. Obviously that in a resolution render low, the point density obviously increased, bt in large resolution, because the fg is viewdependent you don't use more pd.
remember that portal light is almost important, is more good that areaLight classic.
Another question is: material are mayabase or mia_material(x). Reflection or glossines are?.
If not a problem ofr you, try to share your scene, without the furniture, and i try to resolve the render time for best render.


12 December 2009, 03:50 PM
I'm trying to get the portal to work referencing from some tutorials, but it's not coming out right. It seems like the scene needs more photons because the lighting is very low and blotchy. I'm using mia_x materials. I was wondering if I could send you my scene by email?

P.S. Your lighting and ocean simulation looks really nice....

Thanks for the help.

12 December 2009, 01:57 AM
From what I see your floor has some extremely blurred reflections. Do you have other shaders like this. Do they have low glossy settings with high samples? Are they interpolated? You alson might not need a point density at 1 try going lower and comparing the results.

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12 December 2009, 01:57 AM
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