Szark - 29 November 2012 11:57 AM
wancow - 29 November 2012 10:37 AM
Guys, is the shading rate and shadow settings the solution to all render artifacts? I’m getting some very different ones… This is one type.
This is one type of issue I’m seeing (not the only one), sort of shadow lines…
I have UE2, shading rate is 8, Shadow Samples is 16 (on the render settings, I couldn’t find Shadow Samples on the UE2 settings)
A Shading Rate of 8 no wonder you are getting the lines. 0.50 for medium qualtiy, 0.10 even better quailty. (lower is better for shaing rates).
The softer you have the shadows the more you increase the Shadow Samples and lower the Shading Rating value is always a good idea for final renders UE2 doesn’t have Shadows Samples only Occlusion Samples
Waitwaitwait - don’t get Wancow confused - setting shading rate for UE2 to 0.1 is a bit stretching it, to say the least. The general shading rate in the “Advanced” settings - maybe (0.4 - 0.5 is generally good enough unless you’re rendering postmarks). But UE’s own shading rate is good enough at 4.
What works better is to up the Occlusion Samples of the UE. 128 is the default highest IIRC, but if you edit the parameter not to obey limits, you can feed much more to the UE - some people use 512.
Also you could half the “max error” parameter.
And, unless you’re using UE to cast giant directional shadows or GI, turn down the “max trace distance” to something sensible. It’s in centimeters, an inch is 2.5 cm. So 15 cm is generally more than enough for AO and even IDL.
Shadow samples in the general render settings only affects DSMs. If you ARE using DSMs, up it all the way to 64. Or better yet, use shader mixer lights and control the map samples individually. A distant light over a giant piece of architecture may need 160 samples, while a spotlight doing a local “fill light” job can get away with 16.
BUT the thing is, these artifacts wancow posted don’t look like insufficient samples are involved.
One thing may be shadow bias too low - it creates self-shadowing, especially on low-poly models. UE generally handles even a “cornered sphere” well at the default bias; USLK does not, in my experience.
Still, these artifacts look closest to subsurface scattering artifacts. Check if SSS is enabled in the surface shader - since most settings are done only based on “what looks good” (Elite products included), they often fail in lighting environments that don’t match the one the texture artist used. The most scientifically sound way to implement SSS is to set SSS shading rate to 1 or 0.5 (2 also might work for larger images or closeups), and SSS scale to 0.1.
It won’t slow you down much (I’d wager you won’t notice anything on a modern computer), but the artifacts should go away.
