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Amerelium
10-16-2017, 08:24 AM
Hi - a quick question for the experts:

I'm tweeking a rather complex scene - flyover / though of a Culture GSV - mostly outdoor inviroments, LOTS of lighsources (50+) lots of detailing.

I am using raw Monte Carlo radiosity, 24 rays, 2 bounce, and 24 pass AA, 0.01 threshold. For the most complex sequences, each frame takes two hours to render with these settings, so I don't want to go any higeher. Interpolated is also out of the question.

And now my question:

I can slice the render in half simply by reducing the amount of rays from 24 to 12. Now, as long as the amount of AA passes removes all graining, are there other reasons for not doing this? Will the light bouncing itself, so to speak, become more inaccurate. Are there other reasons than graining for keeping the amount of bounces above a certain minimum amount?


Thanks.

Schwyhart
10-16-2017, 12:39 PM
Someone at some point told me to only use 1 bounce.

3dslider
10-16-2017, 01:11 PM
if you decrease ray thus take up more for pass AA, they eliminate noise for GI. Example : 2 bounce, 10 ray, set perspective camera, min sample 16 or 32 (more time but better) without adaptive sampling you will get 'fine' images i think.

Hope that help you.

DAMAKERS
10-16-2017, 02:20 PM
what resolution is the render?

In my case, 4 rays and 1 bounce for exterior in GI brute force Monte Carlo, with 32 passes AA, leaving Shading Samples and Light Samples at 1, with a res of 1920 x 1080 worked fine to me.

It could be a starting point, and up some values if needed, also at higher resolutions, can lower AA to 24, or 12, all depends of the quality u re looking for

Amerelium
10-17-2017, 01:14 AM
I need the two bounces, but, what I want to know is if the amount of rays affect more than just the amount of noise.

If it is just the noise, if there is no lower threshold where the light itself gets messed up, I will lower and compensate what is needed with AA passes.

1920x1080 animation by the way, main sequence is about 2000 frames.

MSherak
10-17-2017, 02:27 PM
I need the two bounces, but, what I want to know is if the amount of rays affect more than just the amount of noise.

If it is just the noise, if there is no lower threshold where the light itself gets messed up, I will lower and compensate what is needed with AA passes.

1920x1080 animation by the way, main sequence is about 2000 frames.

http://www.except.nl/lightwave/RadiosityGuide96/

Still good with 2015...

DAMAKERS
10-17-2017, 03:55 PM
I forgot to mention that color space is important too, i prefer to work in sRGB than linear, let me rise the lights without getting hot spots, the samples that produce hot spots are so hard to clean with low AA passes, if the space color is linear, then should use the clamped lights, it will help a lot, also if there are any HDRI used as light source, reflection or refraction, activating "Limit Dynamic Range" (LW2015, dont remember if older version have it) at "render globals panel" will let the AA clean samples better with low values of AA; the thing is, each scene have particular settings depending of the content in it, there is no universal rule for all scenes but similar ones, this tips should help you in some way

your scene should be very heavy to take 2 hrs, hope you can get better times, and see it when finished, if it is possible ;).

and i second MSherak , an excelent guide from except

Amerelium
10-18-2017, 01:01 AM
You can just google GSV Sleeper Service and you will find the previous version on Vimeo at the top of the list

I'm adding a lot of detailing now, (and changing the FOW a bit) so the render times are now doubled. But it looks like reducing the amount of rays from 24 to 12 is just fine, and taking them right down again to max 1 hr per frame.

I haven't messed around much with light and shadow samples - they are still 4. I might experiment a bit with those as well.



I forgot to mention that color space is important too, i prefer to work in sRGB than linear, let me rise the lights without getting hot spots, the samples that produce hot spots are so hard to clean with low AA passes, if the space color is linear, then should use the clamped lights, it will help a lot, also if there are any HDRI used as light source, reflection or refraction, activating "Limit Dynamic Range" (LW2015, dont remember if older version have it) at "render globals panel" will let the AA clean samples better with low values of AA; the thing is, each scene have particular settings depending of the content in it, there is no universal rule for all scenes but similar ones, this tips should help you in some way

your scene should be very heavy to take 2 hrs, hope you can get better times, and see it when finished, if it is possible ;).

and i second MSherak , an excelent guide from except