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Sebasvideo
08-09-2013, 11:05 AM
I'm reading the 11.6 addendum and it says that samples used to be adjustable for each light independently, but now there's one lighting sampling unified control, and it touts that as being a good thing. I'm kind of confused about that, because it seems to me (and I may be wrong) that it is a one size fits all approach that may increase render times. You may have a light that needs a high number of samples, while you may have another that is not so important that can do fine with just a few without it being noticeable, like interior lights in a spaceship, or something similar. If a light that is very important needs 256 or 512 samples, then this unified setting would put all of them at a number that high, sending render times through the roof. Am I wrong?

RebelHill
08-09-2013, 11:17 AM
This is true, however its not the samples per light/surface, or anything else that really matters (and effects rendertime)... its samples used PER PIXEL which can be filtered using LWs AA and particularly adaptive sampling.


http://www.youtube.com/watch?v=UgNB9tZWUmM&list=PL8A1C0DB658775A63&index=2

jasonwestmas
08-09-2013, 11:20 AM
Only one way to find out. In my view this new sampling system made complex scenes render faster and more simple subjects render slower. So really it totally depends on your type of work that determines if this is a good change or not.

Like others have mentioned in other threads, it totally depends on your approach and that will probably have to change in order to make the best balance between sampling and your AA and AS settings.

tcoursey
08-09-2013, 11:39 AM
The way I look at it is that the samples per light is not important. But the overall image quality IS important. We use Adaptive Sampling on every project and it saves us a ton of time. There once was a time in Lightwave that Adaptive Antialiasing was not great, but it is superb IMO now. With the unified sampling, you dont' have to go around and TWEAK every light shader etc (although there are some shaders that do have sampling in them still) but rather set your final image quality settings appropriatly. Wether it be for a test render or final quality.

Not sure if it makes sense, but click on Adaptive Sampling and set your min to 1 and maximum to 20-40. You'll be surprised I think.... Good luck.

Nicolas Jordan
08-09-2013, 12:04 PM
I also don't agree with or like the global Shading and Light sample settings. It seems to have as many down sides as up sides. There should really be local settings with a global toggle for those who prefer to set these things locally which may help with some scenes.

I always thought AA only refined the pixels in the image in 2D image space after the 3D calculations in the image have been completed. It is also my understanding that Light samples as well as Shading samples are calculated by rays fired in the 3D scene before AA refinement takes place. I really don't see these 2 things as being directly connected at all. High AA and adaptive sampling may help smooth out noise from low Light samples and Shading samples but I don't see AA tied to Light and Shading samples in any direct way.

tcoursey
08-09-2013, 12:59 PM
I also don't agree with or like the global Shading and Light sample settings. It seems to have as many down sides as up sides. There should really be local settings with a global toggle for those who prefer to set these things locally which may help with some scenes.

I always thought AA only refined the pixels in the image in 2D image space after the 3D calculations in the image have been completed. It is also my understanding that Light samples as well as Shading samples are calculated by rays fired in the 3D scene before AA refinement takes place. I really don't see these 2 things as being directly connected at all. High AA and adaptive sampling may help smooth out noise from low Light samples and Shading samples but I don't see AA tied to Light and Shading samples in any direct way.

Yes it would be nice to have a SWITCH letting users decide in different cases to use or not to use unified sampling. That way everyone stays happy.

Sebasvideo
08-09-2013, 01:14 PM
It seems to me that if a project has something that has tons of small lights and only a few that light up a much bigger area, it makes sense to set the big ones to high samples and the small ones to lower samples. I mean, if you have hundreds or dozens of lights, and you need just one or two at 512 samples, with this method you'd have to set them all at 512, and the rendering times would go through the roof. Like this model of the Star Trek Enterprise I've been converting to Modo, I got the geometry and some textures, but I wanted to play with it and I put over 200 lights in many places to make it look more realistic than just luminosity. And obviously it takes a while to render, but I adjust each light's sampling, or groups of lights if they are all part of the same thing. I tried to bring it to Lightwave to compare render times, but I exported an FBX and a Collada and they open very messed up in Lightwave.

tcoursey
08-09-2013, 01:53 PM
Forget about setting samples to anything other than 1. Then change your adaptive samples in the camera settings to something appropriate for your renders. It works great (for our needs) It only adds samples where it needs too based on the threshold I set. ie. min 1 and max 60.

I'm not sure if they directly relate (samples, rays etc..etc) but the end result is faster and just as clean. :)

Nicolas Jordan
08-09-2013, 02:08 PM
Forget about setting samples to anything other than 1. Then change your adaptive samples in the camera settings to something appropriate for your renders. It works great (for our needs) It only adds samples where it needs too based on the threshold I set. ie. min 1 and max 60.

I'm not sure if they directly relate (samples, rays etc..etc) but the end result is faster and just as clean. :)

I should do some simple renderings tests of my own. It is possible I just don't completely understand this new unified sampling even though I have watched plenty of videos on it.

tcoursey
08-09-2013, 03:48 PM
It's also possible I'm not quite understanding your needs/issue but the simpleist answer is to set your light samples to 1 (don't cause any extra render time that isn't needed) while setting your camera to adaptive sampling [min 1 and max 20-60] depending on your scene and surfaces that need extra sampling/anti-aliasing.

You do arch viz as we do. We probably run into the same kinds of issues. Lights, brick morie etc... Good luck.

Phil
08-09-2013, 03:50 PM
I often set min samples to 1-3 (depending on circumstances) and max samples to 512 (particular for geo emitters and MC, with 1RPE). Then tune the adaptive sampling threshold to suit. If the noise is cleaned up before the 512 limit, the remaining iterations blow past in no time at all because AS finds nothing in its review.

spherical
08-10-2013, 03:53 PM
Use DPont's lights (http://dpont.pagesperso-orange.fr/plugins/lights/Additional_Lights.html). Choose between LW Unified or set samples individually.

Nicolas Jordan
08-10-2013, 04:13 PM
Use DPont's lights (http://dpont.pagesperso-orange.fr/plugins/lights/Additional_Lights.html). Choose between LW Unified or set samples individually.

I never thought of trying that. I guess DP Lights will probably work if I really need to control samples per light.

spherical
08-10-2013, 04:37 PM
Works great; especially for GI when using Dome or Area lights. Leave the LW lights at the low sample value and crank up the samples on the problem areas to limit the noise that AA will have to eliminate.

Jen presented a video (http://www.youtube.com/watch?v=8JdONpR6dR8) on Unified Sampling that covers the basics and differences in the sample values in the new system. Start at about 2:45 as you're looking at Dave's P51s while a keyboard glitch is fixed.

IIRC, RebelHill's video (http://www.youtube.com/watch?v=0YFZ2av-BLg) on GI also touches on Unified Sampling.