Subsurface shader and uberenvironment
deleted user
Posts: 1,204
When ever I use Uber lighting and a SSS shader, the render stops when it reaches "said surface" with SSS. It just completely stops the render in its tracks. It sat there in one spot for 18 minutes before I gave up and canceled the render.
It's not a rare event. It happens 100% of the time. I'm forced to either use cheap lighting, or dzDefault shader. Given the ladder I'll use the dzDefault shader, but still I can't help but feel like I'm missing out.
Am I the only person who experiences this?
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Some pause when the SSS surface is first encountered is to be expected - it's a =n effect that requires calculating across the whole mesh (with matching GroupID) to determine the light effect. Global lighting would certainly be something I'd expect to take a long time to complete, compared to a simple directional light, though I haven't seen anything comparable to an eighteen minute wait. Still, it may be worth letting it sit for a while longer.
Well that's the thing. I can't even spot render to see if my surface looks the way I want it to without waiting extreme amounts of time.
Testing your surface settings is not possible with this flaw... They need to fix this issue.
I mean 3 spot tests to see what setting you like best will take an 20 minutes to an hour... This is 2015... It shouldn't take that long for computers to calculate a shadow.
Anyways, I guess I'm not the only one. But still its not excusable to allow such a hang time. This is a technical battle they need to overcome.
Without knowing what your light settings (UE 'quality' settings, etc), shading rates for SSS, overall shading rate, pixel samples, ray trace depth and a host of other settings, it would be near on to impossible to say whether or not your 'hang time' is outrageous or not.
UE on very high quality is a very slow shader...but the results can be amazing.
There are alternates to that combo...but most of the time I hear 'I'm an artist, not a tech person, so that is not going to work for me,"...
'it's too much work'...and so on.
There's a host of information in this thread on speeding up UE and getting great SSS enabled skin (basically with any of the currently available SSS shaders).
http://www.daz3d.com/forums/discussion/21611/
And most of the tips don't involve alternate shaders (even though the greatest speed increases do).
Samples 15x15
Shading rate .5
Everything else is default settings.
Still calculating after 45 minutes... Hasn't moved an inch.
15x15 is pretty dang high...
What's the image size?
That's like trying to calculate everything 15 times for each pixel in the image...yeah, anything over 'thumbnail' is going to take forever, even if you could throw 64 true cores and a couple of hundred GB of RAM at it.
So let's say you are doing a 1280 x 1024 image...that's roughly 20 million shadow calculations...20 million occlusion...you get the idea (oh, yeah, those shadows and occlusion...they are calculated per light source, if the lights are 'enabled'). Pixel samples and shading rate are the main two 'speed' knobs...lower shading = slower render and higher samples = much slower render. And some of those calculations will need to be done before the first pixel is displayed.
This image. renders in about 2 minutes at default samples. At 15, it took over 8 minutes...and that's with one of the faster rendering options, a simple occlusion light and shading rate of 1 (at .5 for the shading rate it was still calculating as I posted).
*****
It finished in just under 10 mins.
I'm now running some tests with SSS....
Just adding the SSS shader with the simple setup and the default samples bumped the render up to 4 and a half hours...I didn't bother doing 15 samples...but my guess would be around 18 to 30 hours for that to run.
And depending on the scene/view most of that time can be spent before the first pixel appears.
Can you please provide screen shots of your
UE settings
Advanced Render Settings
List how many lights you are using with UE
And on the surfaces using the AoA SSS Shader, what is the Shading Rate and Shading Scale set to?
Thank you very much
Why in the world would you need that many samples?
Use Progressive Rendering, and set your shading rate at 1.
But that's just the beginning. As others have stated, you need to let us know what your other settings are.
And a tip: throw away the default quality settings that come with UberEnvironment and create your own based on settings you can readily find in the thread mentioned above and in the 3Delight surface and lighting threads.
You mentioned test rendering... do you use different settings for test renders? You probably ought to.
Oh, and its not calculating shadows when it pauses like that: its doing a subsurface light pass, THAT's what takes so long, its calculating from all the lights in the scene and the UberEnvironment to create the scattering effect.
Because anything lower then 15 Samples Y and 15 Samples X Nets cheap results, and I don't do cheap renders unless I'm forced to.
I waited it out, and this the final result. http://www.daz3d.com/galleryimage/image/63661/the-staff-of-kings_full.jpg
It's a representation of a Dark Angel, Offering up a staff that allows him/her to rule the earth with an iron rod...
Well. In this case, a wooden rod. hehehe
having tested UE against the Advanced Lights by Ageorarmour, you can get the same or better results faster using the Advanced lights then with UE. Even at higher sample rates.