Digital Art Zone

Gedd - 17 September 2012 05:41 PM

...In the process of testing this I went through all of the settings to see which were different/same ...

Thank you for the clarification Richard. The control click was simply a starting point. I also tried ‘update’ with/without control click etc etc etc

I spent hours going through the settings one by one.. using a spreadsheat, laying them out… testing each setting…

It wouldn’t have taken quite as long but unfortunately rendering between setting changes is not instantaneous.

At this point I’m wondering if anyone else has done a thorough test with a detailed texture like Tamesis, where the freckles and subtle skin textures are getting blown out when trying to convert to US2… It appears to point to a significant limitation, flaw even, in the shader.

Gedd - 17 September 2012 05:41 PM

Ok, I have been playing with this quite a bit.. It seems there are some issues with upgrading from HSS to UberSurface2. Looking at the two images we can see that the ‘upgraded’ UberSurface has lost a lot of the texture from the HSS. Now this is after doing an ‘Upgrade’ where the map settings were ignored (left the same.)

In the process of testing this I went through all of the settings to see which were different/same and any that were different I attempted to reset back to the original settings. The spreadsheet shows surfaces with different settings. None of them recovered the lost texture when reset. I am left with the impression that although the two shader both came from Omnifreaker, they are in fact not wired the same, meaning that UberSurface2 has fundamental differences in it’s coding that are in at least this case detrimental.

I specifically chose Tamisis because the textures are particularly suited for this test it seems. Also, this was tested under the default lights, UberEnvironment (shown) and Photo Studio 3, various settings. All show the same results.

I specifically did not alter the textures or surface settings, other then the surface settings that were different between the two, to avoid contaminating the test.

What I noticed straight away was Scatter and Absorption colour set to White. These need to be adjusted. UBS2 has some skin presets you can try to show what type of colours go where and at what settings. I am still unsure what a lot of these functions do exactly. The SSS main colour channel for UBS2 stays White. What colour was SSS set to with HSS? Use that colour in the SSS Scatter channel.

Also make sure Translucency is turned off for now.

Also try turning down the Diffuse strength to 90 - 80% UBS2 uses light some much better some adjustment is often required.

Layer 2 is turned off so that is not causing any issue here.

Apart from that these advanced shader like UBS2 takes a lot of adjusting. If you really want to get a handle on things can I suggest taking a few days out and try the following exercise.

Load Figure and skin texture maps, apply HSS, Use the UBS2 HSS update Preset, no need to hold CTRL down. The remove all the textures and make the figure a med 128,128,128 grey. Load lights and then turn all the different channels off (SSS, Bump, Displacement etc). The do a render. The turn on one channel and render to see the results. Turn that channel off and turn on the next, render and so on. If you change the colour of the effect/channel you are testing to a serious bright colour then you will see the results a lot more clearly. Yes this is very time consuming but it really does help.

Also Trace Displacement in UBS2 is down the bottom and needs to be turned on if you use Displaceemnt maps.

Thanks Szark…

I tried all of the skin presets (and some of the other presets as well,) which supposedly only adjust the SSS. These didn’t help unfortunately. I also tried changing the scatter and absorption colors, they also did not help in recovering the lost texture. Turning down the difuse channel is a good idea, however I tried that also. Translucency is set to exactly what it was in HSS so not sure how that would effect it. As for testing without a texture, it defeats the whole purpose of this exercise. I am specifically trying to maintain detail in a detailed texture.

If I had this set I would ask you to send me the light set up and skin settings so I could try myself. If I get time I will do some testing of my own.

The excercise is to help with understanding what each effect looks like, using a mid grey figure with no textures helps in this regard but as you say it doesn’t help with losing the detail. Have you tried adjusting the lights?

Translucency if set to high or bright colour will make the skin sort of glow. If you have all round lighting and translucency too high then you will lose detail as the skin will be too bright.

Szark - 18 September 2012 09:17 AM

.. Have you tried adjusting the lights?

Used the default lights, UberSurface as indicated, all of Inane Glory’s Photo Studio 3 Presets as they were. I was pretty thorough about testing various lighting configurations with the same results, even though lighting itself shouldn’t be an issue in this case. Spend a day testing before/after with the same surface settings, same lighting rig, same pose, camera position.. just swapping out HSS for US2.

Szark - 18 September 2012 09:19 AM

Translucency if set to high or bright colour will make the skin sort of glow. If you have all round lighting and translucency too high then you will lose detail as the skin will be too bright.

Thanks, I’ve gotten that glow in other situations.. I’ll have to play with this setting next time I get that

Szark - 18 September 2012 09:17 AM

If I get time I will do some testing of my own.

The main issue in testing this is to get a skin that has detail in the texture, freckles, subtle surface textural differences, etc.

Yeah I am with you on losing the freckles (details) etc. I think to best why to approch is keep the textures in place and turn of all the channels then render, turn on a channel and render, turn on the next and render. It might show which channel is fussing with things.

It might help if you took some screens of all Layer one’s settings and posted them here.

Full settings:

I can see some adjustment needed already but I am in the middle of cooking our evening meal so when I finish I will post what I think needs adjusting. No Promises that it will work but some setting are why too high which will give you problems. Be back soon.

Hmm, this looks a bit odd.

What I typically do when I try to convert a HSS and/or UberSurface materials is to use the “!UberSurface2 Upgrade” script without pressing CTRL (nor CMD on Mac) - it preserves the original textures anyway. Don’t use the “!UberSurface2 Base” script for such materials, the starting point there is much less useful.

For conversion I only select the surfaces from 1_Lip to 3_Toenail, as when you e.g. select other surface zones additionally, it might not convert all of them.

I only got few HSS characters unfortunately, a first test with the Stephanie 4 base material shows no immediate visual difference after using the upgrade script here.

Renpatsu - 18 September 2012 11:02 AM

.. use the “!UberSurface2 Upgrade”..

Yes, I started and ended with this. I simply went through all of the other options also.

Renpatsu - 18 September 2012 11:02 AM

For conversion I only select the surfaces from 1_Lip to 3_Toenail, as when you e.g. select other surface zones additionally, it might not convert all of them.

This is a single surface, the face. I did do all of the skin textures, specifically I selected all of the textures labeled ‘omHumanSurface’ only… but in the end for troubleshooting purposes went back to just the face as it had the detail most noticeable.

Renpatsu - 18 September 2012 11:02 AM

I only got few HSS characters unfortunately, a first test with the Stephanie 4 base material shows no immediate visual difference after using the upgrade script here.

The devil is in the details

Actually, it is not just about converting HSS, but in understanding what is going on in general with loosing detail in US2. Whatever is causing this would cause the same results with any detailed texture I believe. I don’t want to try creating something from scratch and run into this either.

Well, quite a few material settings look definitely odd on your side .. you got a bunch of settings at e.g. 100% which I would not expect to be, but it is hard to tell as I don’t got the character in question and some vendors got very odd ideas about surface settings - cannot tell if that is the case here though.

Like Szark suggested, try to turn on and off certain sections, like SSS, Velvet etc, even Specular (which looks very odd value wise, almost Poser material like) - just to identify the root cause in this case.

Edit to add: Almost all of those 100% setting issues may push UberSurface2 over the edge, there are really plentiful settings there which are way too extreme.

Here you go try this for starters Gedd.

Everything looks good until we get to Velvet. In my experience 100% is far too strong 20% is probably a good starting point and Fall Off of about 15%. Velvet is used to simulate fine hairs we have on our bodies.

Subsurface Scattering; US2 does this differently from HSS.

Subsurface Colour; US2 255,255,255 White

Subsurface Refraction; I set to 1.39 given that is what IOR real skin is. But I am not 100% sure on this as we have an IOR setting toward the top of the settings. I have set both to 1.39 but I have not seen any noticeable difference.

Subsurface Scale; Is how thick the skin is IMHO 4 is too thick I always set this to 1.

Subsurface Group; Is used for grouping SSS effects so if you want to use different SSS settings on the Ears fpr example then you can assign a different number so the render engine will treat that area differently than the other group and render accordingly.

Subsurface Shading Rate; is ok at 32 for most images. If using IDL then think about increasing if you get speckling even with the Advanced Render Shading Rate is to .2 or lower.

Subsurface Scatter Colour; This is where we put the SSS colour when it comes to US2. So in this case it would be 116,44,29 (I think that is what the HSS colour is as I can hardly see the image is too small and I saved it to my Computer too. ).

Subsurface Scatter Strength; is something I am still trying to understand. Hence why I suggested using one of the Skin presets that come with US2 to see what he set them to. You can always Undo.

Subsurface Scatter Absorption; Colour and Strength same advice as above. One of the default colours with the presets is a dark yellow/orange. I think this is what colour light gets when absorbed in to the skin, what is left over from the light getting scattered back out though the red blood in our skin.

Translucency; Is why too high at 100%. Try 15% to start with.

Hope this helps