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Posted: 09 January 2013 07:54 PM   [ Ignore ]   [ # 76 ]
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Grr, forgot about that seam, it’s fixed in the scene but I hadn’t bothered to re-render the full length shot since then grin

I was thinking of trying to adjust the specularity and the bump as you mentioned now that I’ve sat with these for a few weeks without working on them. There is some ambient in her as well but it’s using the spec map so it’s predominantly adding a little blush to her cheeks, may have to compare with it off though and see what it does for the final image as she should also be getting some from SSS as well. What I love about US2 is that you can so easily turn on and off different sections without removing the maps so this will be pretty easy to compare.

The spec map is the one that came with the Dublin texture, I’m almost wondering if it’s the glossiness not the spec that’s impacting things, will have to tweak a bit and see what happens or try another spec map.

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Posted: 09 January 2013 08:22 PM   [ Ignore ]   [ # 77 ]
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When I refer to Spec I am including Glossiness too. smile

Rembering what this http://homepage.eircom.net/~neilvpose/ds-settings.htm said what Glossiness and Specualer Strength are can help with this. BUT

I can’t remember if Uber Surfaces’s Glossiness setting is the reverse of the Daz Deafaukt Shader to which that link above refers to. Not having a desktop now I can’t check. Anyways 66% Glossiness with about 10 to 5% Strength might be a good place to start. But I wuld adjust one and test render and so on.

I don’t have this skin set so I can’t look at the spec map and we can’t post them here even reduced in size. It one of thiose PITA things. I like spec maps that look like good bump maps with brighter areas where the sheen should be the highest. So given the principle that Daz Studio uses Grey 128,128,128 has no effect, White is the higest and Black low we should have a mainly light grey map with brighter, even whiter areas of high spec/gloss but with pore detail included.

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Posted: 10 January 2013 05:52 AM   [ Ignore ]   [ # 78 ]
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Yeah, now that I think back I think I mostly kept the values that came from the materials when I applied them and then mostly played with adding maps to different channels and adding in SSS (with maps). That got me a good chunk of the way there but I think it is time to go back and try some tweaking, particularly in the bump and the spec/glossy like you suggested.

Looking at the US2 docs, spec and glossy work as DAZ’s shader does. Personally, I always found the relationship between these 2 confusing until I looked at my TV (yes, my TV). I have an LCD TV where the bezel is a glossy black and the screen is more matte. When the TV is off and the light shines on it you can see that the specular highlight on the bezel is very sharp, mimicking the shape of the window. But, on the screen that same specular highlight spreads out quite a bit, turning into almost a circle, and the edges are quite fuzzy. The brightness of these 2 highlights is almost the same though.

Now take this to DAZ, the specular strength is going to determine how strong the specular highlights are, in the case of my TV they’d be pretty strong and have a white color and both surfaces would have the same strength, or the screen might have a slightly lower strength but not much. But, in the glossy section that’s where things would get interesting, the bezel would have a very high glossy setting while the screen would have a very low setting.

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Posted: 10 January 2013 05:14 PM   [ Ignore ]   [ # 79 ]
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Other thought that came to mind today. Especially with regard to specular and glossiness your lighting can also have a huge impact. As you mentioned in your area light tutorial, point lights and spotlights are just a tiny point of light. This means that with them you’re not always going to get very good looking specular highlight, instead it could just end up being a tiny white dot on the surface.

In my example of the television I mentioned how a lower glossiness setting would make the specular highlight spread out further, and this is true. What UberSurface adds in is a separate sharpness control, I was trying to figure out why you’d want this but then realized the issue with spotlights and point lights. With the DAZ shader reducing the glossiness will cause the specular highlight to spread out more but the edges will also get softer the lower you go. With UberSurface, you have 3 controls; glossiness controls the spread, specular controls how bright/strong the highlights will be, and the sharpness controls how fuzzy the highlight will be. This means that if you were lighting with spotlights you could reduce the glossiness slider to make the highlight spread out more but keep the sharpness high, creating the illusion of a larger light on a glossy surface.

Or, you could just follow your excellent area light tutorial and use mesh lights so that you get realistic looking specular highlights :D

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Posted: 12 January 2013 05:40 PM   [ Ignore ]   [ # 80 ]
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Glossiness is how big an area the highlight is/are
Specular Strength is how strong the Glossiness is

And yes lighting does play a part as does Diffuse Strength. If I am using any advanced shaders and lighting I tend to work at 80% Diffuse strength or even lower if needed. This can help when using advanced lighting like Global Illumination or HDRI with Indirect Lighting.

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Posted: 30 January 2013 05:53 AM   [ Ignore ]   [ # 81 ]
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Wow, I knew lighting would impact the specular highlights but I’m shocked how much of a difference this made. I switched over to a single area light “soft box” and uber environment set to indirect lighting with soft shadows (I tried GI but after 10 hours of rendering still left it at 5% I stopped that for now). I put her into a big cube which I sub-divided to round the edges thinking that might help with the bounce, not sure if that’s needed for indirect lighting but I could imagine it would with GI, which was looking really nice but taking forever. I had to play with the intensity for UE a bit to keep things from blowing out too much but it wasn’t too rough.

The only other changes in this render are I turned off ambient on all of Genesis’ surfaces and increased the bump somewhat on all of the skin surfaces. The specular and glossiness settings were untouched but the change in lighting has taken care of that problem nicely.

There’s still something “off” in this image and I’m having a hard time coming up with where to go. It’s still the best skin render I’ve done to date but I’m trying to figure out where to go next. Unfortunately, switching out the lighting means that draft renders are a lot tougher since I have to keep the quality settings dialed up to get rid of the noise from the area light and UE so it’s a little tougher to do further tweaking.

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Posted: 30 January 2013 07:59 AM   [ Ignore ]   [ # 82 ]
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adacey: That’s a beautiful render! I love the lighting and the surfaces look very realistic. You say there’s still something off about this image…first thing I noticed was that her hair is flowing into her chest, especially on the left side (from her perspective). There should be morph sliders to fix that (sorry if that’s been mentioned…I admit I haven’t read every post). Aside from that, if you’re going for pure realism, I’d say her eyes are too big and/or her mouth is too small.

Very impressive work overall, though! I’ll have to try that cube thing…I’ve heard it works wonders.

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Posted: 30 January 2013 03:45 PM   [ Ignore ]   [ # 83 ]
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Thanks Scott, I think you’re right that the skin isn’t the issue now. I do really need to see if I can improve the hair and her eyes next. For the hair, I think some parts are just a limitation to the hair prop, which is unfortunate because overall I like it. Particularly, right below her ears (especially on her right) I find I can just see the geometry too much and the drape feels wrong. So I think I need to play with the morphs a bit to fix some of that and then start digging into the surfaces. So far, all I’ve done was take the base prop and ran it through an Uber Hair preset, it’s a good starting point but maybe I can take that further.

Similarly, for her eyes they could be a bit big, I did put some Aiko into her head which does increase the eye size, I thought I dialed that back out but I’ll double check if I can fix that a bit more. The other thing that’s bugging me is that right now the eyes look off for the lighting. Fortunately, the eyes I’m using don’t have burned on highlights but they do have a reflection map and transparency map applied to the cornea surface to fake the catch lights. Now that I’ve put her in the cube and am using an area light I should be able to play with the cornea material to get a raytraced reflection and I think that will help things a lot so that the catch lights match the lighting better.

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Posted: 01 February 2013 08:33 AM   [ Ignore ]   [ # 84 ]
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Progress! Applied some morphs to fix the hair positioning, was shocked at how bad the collision was there and that I hadn’t noticed it before, I think the transparency on the hair was throwing me. I still see some spots, especially on her right, but it’s a big improvement. I’m finding it a little challenging to dial in the right mix of morphs to create a realistic drape without it creating tons of poke through problems. I might end up rendering the hair separately and using that as a layer in post to fix these niggling spots, might be easier than fighting with it in DAZ.

I took a quick look at the hair surfaces and noticed that the uber hair upgrade had loaded several maps in but left the channel set to off, the 2 biggies being bump and displacement. I’d seen this a couple times before with Uber Surface 2 upgrades, not sure what does it but it was simple enough to enable those channels that had maps loaded and it’s improved the hair quite a bit, may still tweak it further but it’s getting there.

For the eyes, I removed the transparency map and reflection map on the cornea surface and instead put raytraced reflections on and set the cornea to 0% opacity, giving me just the reflections. At first, I was picking up way too much grey from the box (there’s no material on it) unless I dialed back the reflection strength and that was killing the catch lights. Turning fresnel on killed the grey reflections but has resulted in the iris being very, very dark.

Overall, I’m happy with the progress here, just need to dial in the eye materials a bit better and I think I’ll be at a pretty good stopping point, right now I find the dark eyes very unnerving.

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Posted: 06 February 2013 07:41 AM   [ Ignore ]   [ # 85 ]
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Sorry I haven’t been around but it is hard to get on online these days.

Wow great improvement adacey. I think this is a great start in understanding some of the more advanced (well advanced for Daz Studio smile ) shaders and light.

I do have an old P3 desktop that I am borrowing until I get a new workstation so if I get a chance I will take a look at the eye settings…..these are the gateway to the soul and getting them right helps push the realism. I am in the middle of a picture now so time is short but I am nearing the completion so hopefully I will get to help more with this side of things.

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Posted: 06 February 2013 04:11 PM   [ Ignore ]   [ # 86 ]
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Thanks Szark,

What I’m finding odd is that when I zoom right in to the eye for doing a test render it looks better so I think this might just be a situation where too much detail is being blended together. May have to try a higher resolution render and see what happens.

The only other thought was that I noticed that when I tried repeating the full body camera angle that there was quite a bit of shadow banding, I think this may be due to the shadows samples being too low for the area light (I think it’s on defaults right now), not sure if that would impact that or not but it’s worth digging into the light’s settings again to see what’s there.

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Posted: 06 February 2013 04:14 PM   [ Ignore ]   [ # 87 ]
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Try lowering the Shading rate in the Advanced Render Settings Pane to about 0,20 - 0.10 for finer detail and shadow banding. Yes with using Area lighting and it being soft in nature increasing the shadow samples will help too.

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Posted: 06 February 2013 04:18 PM   [ Ignore ]   [ # 88 ]
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I’m already using 0.10 as the shading rate in my render settings and the banding was in the shadow on her arms and legs, which would mainly be coming from the area light only so that’s what pointed me in that direction. I’d already cranked up the UE settings using the highest quality preset but I just checked and the area light was at 128 so now I’m not so sure.

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Posted: 06 February 2013 04:23 PM   [ Ignore ]   [ # 89 ]
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Ok try increasing the Shadow Samples of the Area light too, start at 16.

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Posted: 06 February 2013 07:14 PM   [ Ignore ]   [ # 90 ]
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Shadow samples for UE and the Area light were both at 128 so it’s not that. I did notice the shading rate for UE was at 8 so I’ve dropped that down to 1 and it seems to be improving things. I think its shadow bias is impacting things more due to it being just the 1 area light and the UE for fill so a lot of the light is coming from the UE.

Edit: I originally said shadow bias but it was the shading rate, 1 got rid of a lot but now trying 0.5

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