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#1 2012-05-28 10:53:47
FG Equivalent to Brute/exact?
Hello!
What is the FG equivalent to Exact/Brute force calculation? That is, I don't want it to interpolate a map, but actually want the real brute force calculation ("film grain" is a typical side effect to this).
thanks!
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#2 2012-05-28 11:17:37
- gducatel
- Beta tester
- From: Montreal
- Registered: 2007-11-13
- Posts: 56
Re: FG Equivalent to Brute/exact?
Hi,
My guess, would be just use the ray-traced color bleeding algorithm inside the Global Illumination tab of the render settings.
Cheers,
Greg
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#3 2012-05-28 18:38:34
Re: FG Equivalent to Brute/exact?
The closest technique to FG is the ray-traced color bleeding (using UI namings). When FG runs in brute force there is basically no interpolation (you can still have more than one FG ray per fg point). I don;t think there is any interpolation happening with indirectdiffuse() which is the shadeop running when ray-trced color bleeding is chosen, the only thing one should do to mimic IMO is to switch off adaptive sampling which is probably ON by default in the oparameter list of tha maya gi light (see the RSL .h shaders and eventually edit though I do not recommend it, if you need film grain you should do it in comp).
P
paolo berto
/*jupiter jazz*/ — visual research
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#4 2012-05-29 20:00:00
Re: FG Equivalent to Brute/exact?
Hello NinjaPower,
The ray-traced color bleeding is what you are looking for. You can also increase the diffuse bounces to "2" in the optimization tab and turn on photon-mapping. This makes the algorithm behave as follows:
1- Exact evaluation for first bounce.
2- FG evaluation for second bounce.
This usually leads to good results because you don't see the "splotchiness" associated with FG at the first bounce.
Tell us how it goes,
-- aghiles
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#5 2012-06-02 11:02:04
- CiaranM
- Beta tester
- Registered: 2007-11-14
- Posts: 78
Re: FG Equivalent to Brute/exact?
Here's a real quick and dirty test of that ray-trace/FG workflow:
https://vimeo.com/43304503
128 samples and 500k photons.
About 45 mins per frame, there's still a little noise in the occluded areas and photon flickering is barely visible (pardon for the crappy vimeo compression). Actually, it's pretty comparable to the render time I would get with a leading brute-force ray-tracer, if I wanted such a low level of noise. I'm just using OOTB shaders.
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#7 2012-06-05 15:43:39
- CiaranM
- Beta tester
- Registered: 2007-11-14
- Posts: 78
Re: FG Equivalent to Brute/exact?
Sure, here you go: https://dl.dropbox.com/u/14344332/3D/3D … e_Demo.scn
Remember, it's pretty helpful to turn on progressive ray-tracing when you're tuning a scene like this, since you'll get immediate feedback!
Last edited by CiaranM (2012-06-05 15:47:04)
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