Show Us Your Iray Renders. Part II
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That's a good suggestion that I haven't tried yet. I'll get into that tonight, and post my results.
After spending the day playing with skin texture shading and lighting, I am very pleased with this final render.
:-)
Credit for use of HDRI Sierra Madre B kindly given free by http://www.hdrlabs.com/sibl/archive.html
Ah, so that happens to you too...yeah I could not figure out what was wrong there because I had the HDRI lined up almost exactly the same in both programs (using a background truck as reference). I wonder if we might need to turn up that relief scale (can't recall the exact name) in Substance Painter to better preview how it will look in Studio if the normals are being calculated differently somehow. At least we're making progress, and I thank you again for your help with this. :)
Things like that scream "wrong IOR" or something not right with the Fresnel calculations...
I haven't played around with the materials to know if that's the case or not. In fact, I'm not even sure if those are settings you can adjust. I've just been loading some stuff and letting it 'autoconvert' or things like Sickle's scene. I don't get much time to use the machine that 4.8 is on, so I can't check. (yeah...4.8 is on the HTPC...it's the one with 64 bit Windows AND an Nvidia graphics card...).
Looking cool! I see something in your render which has been an issue for me as well - a sort of artifact at the glancing edges of objects with heavy Normal mapping. The Substance Painter render shows light reflecting around the edges of the skin ball in a lovely natural looking way, but the DAZ render shows that something is off there, with the artifacts increasing as you get to the edge of the ball. I haven't found any sort of workaround for this aside from turning down the strength of the Normal map. I have a model of a sidewalk with a lot of Normal map texture that looks great, except all these dark spots appear if you look at it from a glancing angle. Maybe this too will be fixed with the next release (or we'll learn something new about creating Normal maps that shows we've been doing it wrong!).
It's different math in the fresnel calculations. The Substance Painter metal/roughness shader is based on the UE4 shader which was based on Disney/Pixar's principled BRDF. The Disney shader uses Schlick's Approximation for the top coat, the UE4/Painter shader is very similar math but slightly optimized for real time engines and it gets combined with base specularity instead of separate layers.
The "custom curve" option in Iray's top coat is also using Schlick's Approximation and the default settings should match what's found in the UE4 shader, using that and what cjones mentioned earlier about setting up your roughness maps before exporting should help in getting a better match. You'll have to experiment of course since base and top coat are separate but once you find settings you like you can keep using them since the maps are doing the heavy work. It's also pretty simple to set up your own top coat layer in Painter if you want different maps.
Normal maps could be a bit more problematic, Iray is most likely using a different tangent basis than Substance Painter. Tangent basis is the math used to calculate normals in tangent space. Painter is using Mikk-T tangent basis(though some people claim it's a bit "off") and Iray might be using 3DS Max tangent basis or something else entirely. There's a program called Handplane that will convert normal maps to be used in different programs with mismatched tangent basis but without knowing exactly what Iray(...or 3Delight) is using it can be a hair pulling experience. You might have to settle for "close enough"
There's also a Height multiplier in Substance Painter that I find I have to turn down a lot to get a similar look in Studio, that by itself might be enough for you.
...this is all from memory(which is terrible) so I'm probably getting who did what wrong but it should give some clues if you want to look into it further.
#1 - Olympia 6 HD with some tweaks
#2 - Same as #1 but with green channel inverted on normal maps
Which one looks better?
I'll be 100% honest with you, I can't tell a difference. They both look nice.
Version A looks correct to me, for what the V6 Normal maps are supposed to do, adding definition to the lips in particular.
That might not answer the question fully though, as the Normal maps we're wondering about are coming from Substance Painter, and the problem may be that Substance Painter export options are not set up perfectly for DAZ Iray by default. They're close! But it looks like it's going to take some investigating.
It's hard to tell with the images smaller, but if you load 1st one and then the other, you can go back and forth between the two and see one has details around the lips and ears that are more defined. Not much of an appreciable difference any where else on the images. They both look good, so it becomes a matter of preference. The image with less detail around the lips and ears is the one with the green channel inverted.
I prefer the first image, myself.
Thanks for sharing your knowledge, that gives us quite a lot to chew on! A lot of interesting stuff in what you wrote, and really good tips. I'm going to set up a simple test like SnowSultan's, and try various export settings to see if I can get a result in DAZ that accurately matches the Substance Painter preview render.
Could be a difference in monitors. She has quite the healthy glow on my monitor.
All that was from memory?? All I can say after that explanation is "uhhhhhhhh maybe I'll just wait for a tutorial". ;)
Some tests with SIBL HDRi below. I find them good enough for lightning but are too small for background; The problem is that big texture HDR will eat a lot of memory in a graphic card
Heh, I thought #2 looked better :)
I guess what's bugging me about #1 is that the edge of her bottom lip doesn't align exactly with the color.
With an sIBL set you're supposed to use the hdr/exr for lighting only, and the jpg as a backdrop. See this thread: http://www.daz3d.com/forums/discussion/54158/
Heh, I thought #2 looked better :)
I guess what's bugging me about #1 is that the edge of her bottom lip doesn't align exactly with the color.As you probably know, when you select "Skin", the lips are not included with that, neither is nails (finger and toe).
(EDIT)
"O" and quite a few figures, have drastically different bump and displacement settings on the lips, from the face.
With an sIBL set you're supposed to use the hdr/exr for lighting only, and the jpg as a backdrop. See this thread: http://www.daz3d.com/forums/discussion/54158/
I know but it's a bit limiting with the backdrop . I'm gonna try higher res later
Yup, when exporting the material out of Substance Painter, inverting the green channel on the Normal Map made my DAZ render look a lot more like what I was seeing in Substance Painter. I did the green channel inverting in Photoshop, I'll have to see if there is a setting to automatically export it this way from Substance Painter.
Hole, you mentioned the tip that cjones had about turning off the roughness squared hidden parameter in Substance Painter. I can't find anything about this hidden parameter in the Painter manual, online, or anywhere really. Is this option in the current version of Painter, and if so could I trouble you show me where I can find it?
....I knew I was remembering something wrong, I was confusing what he said with something Wes posted on Allegorithmic's forums for remapping the roughness channel to export better for Unity.
cjones is referring to a hidden switch in the daz surfaces pane, if you check "show hidden properties" it should show up at the bottom
...even easier than what I was thinking.
You want OpenGL for your normal map format , you can switch it in Painter by going to edit>project configuration but that doesn't change your input normal map.
The roughness squared appears in a Disney Physically-Based Shading rendering paper. Have not seen it as a setting in Substance painter.
Thanks for the info!
A image I did to play with materials and emission. The HDR is from the sIBL archive. Had to downsize it for the forum but I'll probably put the full size up in the gallery.
Zahara Portrait.
My renders for today with Iray..
HDRI maps for lighting
Custom material settings
A new day, a new Iray image. Custom material settings in an HDRI environment, with 32bit grading in PS. Enjoy! :-)
A lovely way to start the day! Darkon Cinematic Realness snatches all the trophies! ;-)
Go Cath Go!
Thanks Alex.. lovely work
I made one more
The Coal Miner
A lovely way to start the day! Darkon Cinematic Realness snatches all the trophies! ;-)
Go Cath Go!
After struggling a bit with a few of the sIBL free HDRI maps, I got the free sample from Aversis to decompress. (Stuffit Expander disliked the first attempt.) Once I figured out what controls to tweak, I like it. There was no need for gamma correction. There was sunlight, and you knew where it was coming from. The model stood cleanly in her own shadow. The dome seems a bit out of focus, but perhaps I have been playing too long in an alternate reality where the depth of field has been disabled.
Will there always be a sense, though, that one knows precisely where the HDRI stops and the digital modeling begins? Does anyone enable depth of field just to make the render slightly imperfect?
Rendered with one of the Dutch Skies HDRI maps. Dome scaled to 10%. Bike: all Iray shaders. Biker: Apollo Maximus straight out of the box, no Iray shaders. Just added the patch to the vest texture. I really like the way Iray handles clothes. I'm still playing with skin, but in some cases the difference is so little, it's hardly worth the trouble. I've seen a lot of ways around to get a HDRI map to work really well, with seperate background renders and such. But a good map, like this one can also do the trick.
Personally I think this is one of the things DAZ needs to work on as far as improving the 4.8 version. It seems a bit silly that you have to make sidesteps to get a HDRI lighting work and have a descent background.
I like the render.
How much is DAZ 4.8 the problem and how much is it the quality of the HDRI file? Either way, life could be easier.
The attached is HDRI lighting but with the dome not rendered. The building is old style surfaces, while the mud is Iray leather.
I wish I had your skill with the custom render settings!