AO vs IDL
trying to see how Uberenvironment 2 works, so I have tried lighting the same scene with UE2 (at 4XHigh setting) and no other lights and just comparing AO with directional shadows and IDL with directional shadows (see image). In both cases, the map is HDR kitchen
I was under the impression from tutorials that the IDL option gives a more realistic look that AO but at the expense of longer render times.
But compare these test renders. To me, the IDL version looks less good. It looks more artifically "lit up" and the girl's skin appears to glow rather unnaturally. (both are with no adjustments to settings like strength, contrasts etc)
What am I doing wrong?
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Comments
I'd argue that the IDL is more accurate. The sphere in the AO image shows the obvious quads which make up it's surface more distinctly, and light more accurately spreads through the scene in the IDL. Of course, results will vary depending on other lights placed in the scene and the scene itself, so what works for one might not necessarily work for another.
You'll also want to read through this thread: http://www.daz3d.com/forums/discussion/18998/
UE2 is bugged in that the rotation between where the light should be coming from, and where it's actually coming from is off.
IDL in this sense refers to colour bleeding from one surface to another. It doesn't bounce light around like the GI supposed to. :)
Also Directional shadows are weak and IMHO shouldn't be used when doing realistic type of images. Best to use another light source using Ray Tarced Shadows to provide directional shadows.
Also when using IDL drop the IDL Strength slider, I find 50 to 75% to be a good start.
Ok, so here it is with IDL strength dropped to 50%. It's certainly better - although now I can't really see much difference from the AO version. Worth the extra render time?
By the way, what's causing that shadow half way up the back wall? There are no other lights in the scene
Oh don't get me wrong Directional shadows works as you can see here but I was saying if you want bettter and more accurate directional shadows then using another light source like a Distant Light for the sun will work so much better.
Also what is your Maximum Trace Distance set to in the UE2 Parameters. This is the distance between objects that AO and IDL will occur at. Dropping it down to 45 (45 cm or 18 inch) is about right for an indoor scene.
IDL will give colour bleed from one surface to another if there are close enough like where the floor and sphere meet is still lighter than the AO render. In the top IDL ic see the back corner of the white wall and see how there is a white band in the corner all the way down...that is you IDL at work.
For this image from what I see out the window and given the wall colours 60 - 70% IDL should do nicely.
thanks. I'll try those settings. By the way, do you know what's causing that shadow half way up the back wall? Could that be the "sun" in the kitchen map in the IBL causing a shadow from the 1st floor landing? (or don't IBLs cause shadows?)
Yes sort of. Put it this way the light parts of the HDRI map will make the most light and in a way yes it could be darker areas casuing that.. Also the quality of the maps are important too. I wouldn't say these are bad just not high enough a quality for me.
are you talking about the maps that come with UE2?
are you talking about the maps that come with UE2?yes
ok here's with the settings you recommended. Looking good now. :)
Nice. Ok now to get to work on the surfaces. :)
Also this is the only trouble with using UE2 on its own, it doesn't give good specular highlights, well none to be more precise. This is where extra lighting comes in the play. Area Lighting will also make it hard to get good specular highlights.
Luckily in 3DL you can create specular only light sources, so you can get some highlights without needing to worry about blowing out the detail with excess light.