Digital Art Zone

scorpio64dragon - 17 June 2012 08:23 AM

How have you been rendering if you haven’t been using cameras?

Khory mentioned the perspective view. I rarely, if ever, change the view when working on a scene. I just always leave it on perspective, and I’ve been able to render every scene I’ve done in either .jpg or .png with no problem. But to answer your question, I just hit “Render”, and it works.

Perspective view is a great thing to use when you’re setting up your scene - it’s basically a “director’s camera” as in its movements won’t get recorded into an undo list.

But as for using it as a render cam - apart from being AFAIK unable to set the focal length which is, to me, essential - it’s most useful for people who do their setting up and rendering in a single step, i.e. do not close the program/reload the scene, for the very same reason - when a scene is reloaded, the perspective view always goes back to default position (at least, in the versions of Studio I’m using)

While the cameras’ position will get saved within the scene. You can have several different cameras, and they all will get saved. Very handy for looking for that elusive perfect angle…

Let alone the shader mixer cameras that will allow for some extra cool effects like indirect lighting etc.

As for the OP’s render, it certainly is beginning to look good! I’d wonder, though, if s/he’s forgotten to include the “Lips” surface in the latest round of adjustments…

Here’s a nice tutorial on skin settings by Toadz: http://toadz.deviantart.com/gallery/?catpath=/resources/tutorials/

There’s some points I disagree with, though:

- first of all, if you use subsurface scattering, please use SSS scale 0.1 and a SSS shading rate of 2, 1 or lower (2 and 1 are generally fine for closeups, the farther you move away, the lower the value needs to be; on the other hand, the farther away you move, the less chances you do need the SSS =) ) A SSS shading rate of 1 will not slow you down that much even on an older computer, and this combination of scale and shading rate is the way to get the SSS to be calculated right, as it gives 3Delight the correct dimensions, and SSS is dependent on the size of object.

- then, I haven’t ever seen any effect of translucency on meshes that aren’t zero-thickness. Vickie is not zero-thickness =) So, for most “normal” circumstances, you won’t really need translucency for skin… but sometimes it’s really good for the hair!

- displacement is generally only better than bump mapping if you want the outline of your mesh altered - like when you’re rendering strong veins (or warts…) Or if you want two relief “layers” (think tooled leather) Otherwise it’s perfectly possible to do without it and shave off some render time.

- as Khory (from whose awesome products I’ve learnt a lot!) has rightfully mentioned, the easiest way to make specular look better on skin is to use a bump map for specular strength. The “no spec maps” method doesn’t really produce “natural” looking highlights - at least, I have yet to meet a person whose forearm and hand skin would shine as much as in the images done with that “no spec maps” approach. Generally the shiniest (=oiliest) areas of the human skin are the face and neck/chest/upper back/shoulders (at least on people from Russia and Finland, i.e. those I see around me). Sometimes palms/soles. //note: I don’t render or view full nudity, so maybe there are other areas too… but just not the arms, OK?//

When using shaders like HSS or UberSurface, I also like using blurred lower strength reflection on skin instead of specular. It’s fast with a reflection map, but finding a suitable one can get tricky. The Kitchen from the UE can work really well, especially if you use it to light the scene from UE. I’d add that then, to match the reflection and the lighting when you need the light rotated, it’s best to go the old way and rotate the whole scene but not the UE. There may be a way to rotate surface reflection maps through shader mixer, but I haven’t found it yet…

And here’s also a very cool tutorial for great skin using the basic Studio shaders: http://afina79.deviantart.com/art/Sugar-Skin-In-Daz-Studio-159087559?q=favby:mustakettu85/43351052&qo=21

This is where you should disregard the reflection bit, though - the default shader doesn’t seem to catch any reflection when set to “skin” lighting mode.

Sorry if that’s too much!! I’m just trying to help.

- then, I haven’t ever seen any effect of translucency on meshes that aren’t zero-thickness. Vickie is not zero-thickness =) So, for most “normal” circumstances, you won’t really need translucency for skin… but sometimes it’s really good for the hair!

I suspect that the translucence stuff comes more from reality than rendering reality (sometimes there is a huge difference between the two). Even things we would never think of as translucent (letting light through) have translucence in “nature”. If you pound a piece of gold thin enough it becomes translucent and eventually somewhat transparent. Stone has some translucence as well. We just never see them sliced thinly enough. Humans have a fair bit of translucence but it only shows around the thinner parts of the body. In a really perfect 3d world there would be strength maps that controlled where the translucence was used on the figure and how strongly. I suspect that the use of translucence on characters is partly to lower the amount of sss that needs to be used.

- displacement is generally only better than bump mapping if you want the outline of your mesh altered - like when you’re rendering strong veins (or warts…) Or if you want two relief “layers” (think tooled leather) Otherwise it’s perfectly possible to do without it and shave off some render time.

In another “perfect” scenario displacement would only be used on figures for places like the lips, warts/moles, and veining. Things that when viewed from an angle actually bump up off our skin.

- as Khory (from whose awesome products I’ve learnt a lot!) has rightfully mentioned, the easiest way to make specular look better on skin is to use a bump map for specular strength. The “no spec maps” method doesn’t really produce “natural” looking highlights - at least, I have yet to meet a person whose forearm and hand skin would shine as much as in the images done with that “no spec maps” approach. Generally the shiniest (=oiliest) areas of the human skin are the face and neck/chest/upper back/shoulders (at least on people from Russia and Finland, i.e. those I see around me). Sometimes palms/soles. //note: I don’t render or view full nudity, so maybe there are other areas too… but just not the arms, OK?//

Specularity maps for characters is another place where we often lack a “best case” scenario. Ideally specularity maps would only highlight were we tend to be most oily/glossy. The “t zone” on the face, lips with lipstick, a rather light amount on shoulders and arms etc. Then those highlights would be broken up by a good bump map so they didn’t come across as slick.

When using shaders like HSS or UberSurface, I also like using blurred lower strength reflection on skin instead of specular.

In theory that is what Fresnel does or should do..

I’ve always had sort of conceptual issue with reflection maps/IBL maps. The idea is that we and everything reflect a small percentage of the colors/reflected light/what ever it is and hence the colored maps. But I’ve always wondered if its really ideal unless they actually match the scene that is being rendered. Other wise the colors would be sort of random right? Not really relevant I know but its something my mind wanders to when I try and pick out an image to use for an IBL.

Khory - 29 June 2012 12:34 PM

I suspect that the translucence stuff comes more from reality than rendering reality (sometimes there is a huge difference between the two). Even things we would never think of as translucent (letting light through) have translucence in “nature”. If you pound a piece of gold thin enough it becomes translucent and eventually somewhat transparent.

You just gave me an idea… I’m going to make a “coin” (heavily flattened cylinder), put a light behind it and see if I could get the translucency to show through a solid mesh…

In another “perfect” scenario displacement would only be used on figures for places like the lips, warts/moles, and veining. Things that when viewed from an angle actually bump up off our skin.

One thing I’ve never really managed to do (not enough trying, I guess) was create a “perfect” displacement map to use on lips, to make the transition between “skin” and “lip” regions more organic…

Specularity maps for characters is another place where we often lack a “best case” scenario. Ideally specularity maps would only highlight were we tend to be most oily/glossy. The “t zone” on the face, lips with lipstick, a rather light amount on shoulders and arms etc. Then those highlights would be broken up by a good bump map so they didn’t come across as slick.

Absolutely! Yet this is where bump maps that only stay in the bump channel don’t really seem to work. Probably because of resolution - the actual relief texture on hand/arm skin is so minute in scale IRL, yet so important for the scattering of light. A procedural fractal pattern seems to be the way to go, but I haven’t yet managed to recreate a suitable pattern with the shader mixer noises…

Most often I get nicer results when plugging the bump into spec strength, yet sometimes into spec colour or both… A lot depends on the map. Actually a lot of maps that get passed around for “bump” or “spec” aren’t really suitable for either.

I also found that in shader mixer, when you use a map to drive a parameter, moving its percentage slider has no effect, unlike in default and uber shaders. I wonder if there’s a way to work around this? Maybe a math node?

In theory that is what Fresnel does or should do..

Fresnel is one of those areas I can’t seem to grasp. It should “make the reflection at glancing angles stronger than direct” (to quote Omnifreaker’s wiki from memory), but what exactly are glancing angles? Are they “glancing” relative to the light source rays or the camera rays? What materials would need the Fresnel law to be described properly? Does skin need it?

I’ve always had sort of conceptual issue with reflection maps/IBL maps. The idea is that we and everything reflect a small percentage of the colors/reflected light/what ever it is and hence the colored maps. But I’ve always wondered if its really ideal unless they actually match the scene that is being rendered. Other wise the colors would be sort of random right? Not really relevant I know but its something my mind wanders to when I try and pick out an image to use for an IBL.

Yeah, I agree maps are those “sort of random” colours. So it’s always a sort of a compromise. I try to match the colour scheme of the scene when I choose my images.

I tried blurred raytraced reflections once, and it looked very cool, but took quite a while to render. Plus, raytraced reflections, like indirect lighting, need a fully 360 degree setup scene for rays/photons to hit something (otherwise they just return the colour of the void, black). I guess it’s awesome for interiors, but for an outdoor scene you’d need a lot of memory for all the props unless you’re using a skydome… and then it’s easier and faster to use a light/reflection map that matches it.

One thing I’ve never really managed to do (not enough trying, I guess) was create a “perfect” displacement map to use on lips, to make the transition between “skin” and “lip” regions more organic…

For younger lips most of the displacement would be near the opening of the mouth. That tends to be where the majority of difference is hight wise. Older lips would be trickier because peoples lips tend to narrow and loose thickness causing almost a rut near the inside of the lips. I’ve made special displacement maps a couple of times in the past and only highlighted to raise the parts that were clearly higher on the texture.

Are they “glancing” relative to the light source rays or the camera rays?

That I don’t know. But body shine really only shows up when we are angular to the surface. Lest you look down at your fore arm and say “but I am looking right at it”, keep in mind that it is a curved surface and that cause at least some angularity on the surface itself. That angularity should in theory trigger the fresnel reflection in a render. With quite a few things I have started upping fresnel and lowering specularity (since specularity is really just easy/time saving way to get an element of reflection).

You know, I read this stuff and my head spins. But I suppose with some time and practice, I can get this stuff too.

Sounds like we are talking some crazy alter language right? I felt exactly like that when I first started. Then one day a light bulb goes off and it starts to click. Some of it you will see know and a year or two from now you will go “oh I know what that was now!”. And some of it may be stuff you never really develop an interest in. Not every one geeks out over surfaces like I do for example.

Khory - 29 June 2012 06:43 PM

For younger lips most of the displacement would be near the opening of the mouth. That tends to be where the majority of difference is hight wise. Older lips would be trickier because peoples lips tend to narrow and loose thickness causing almost a rut near the inside of the lips. I’ve made special displacement maps a couple of times in the past and only highlighted to raise the parts that were clearly higher on the texture.

Yes, when the “body” isn’t there, the correct shape is tricky to get. Moreover, even younger but thinner lips I found hard to make believable when using our favourite figures. They all tend to have fuller lips, and whenever I tried to morph them, I wound up with polygons creasing and forming sharper edges alongside the outline of lips. I should try some more custom morphing, and probably not with sculpting brushes but with precision moving of vertices, but I used to think a displacement map could help me even out the problem areas and create the more subtle relief when needed.

I guess I just pick wrong subjects to recreate in 3D and should stick with whatever cute faces are popular to render LOL

Khory - 29 June 2012 06:43 PM

Are they “glancing” relative to the light source rays or the camera rays?

That I don’t know. But body shine really only shows up when we are angular to the surface. Lest you look down at your fore arm and say “but I am looking right at it”, keep in mind that it is a curved surface and that cause at least some angularity on the surface itself. That angularity should in theory trigger the fresnel reflection in a render. With quite a few things I have started upping fresnel and lowering specularity (since specularity is really just easy/time saving way to get an element of reflection).

Thanks! Actually this is when I get conceptually stuck because when I look at my arm with its complex shape I have no idea which “facets” are normal to my line of sight - and what’s worse, it changes shape when I turn my hand LOL

I guess I should ask a friend to pose for reference pics in an environment with controllable lighting, so that I’d be able to get an idea of what really happens with regards to ray angles. Now if only I could find such an environment without paying for a studio =)

Khory - 29 June 2012 11:58 PM

And some of it may be stuff you never really develop an interest in. Not every one geeks out over surfaces like I do for example.

You know, surfaces is what got me into the whole 3D affair! =) And not just “skin”, this came last…

Anyway, I’d like to wish good luck and much inspiration to Blackbirdwake, Megarig, and everyone else who might be reading! =)

Quick update on using Translucency with solid meshes (UberSurface, translucency strength 100%, colour fuchsia):

A cylinder 31 cm in diameter, a single spotlight with a raytraced shadow pointing from behind (25 cm from the cylinder’s surface).

I was changing the height of the cylinder: 1 cm tall, 0.99 cm tall and 0.89 cm tall, and here are the results… so, for human ears it may be useful, but for general skin - no

And here’s an explanation of Fresnel that made sense to me…

http://filmicgames.com/archives/557

Thank you for the Fresnel information. I don’t think the stuff I had looked at before had had images.

Khory - 21 July 2012 03:33 PM

Thank you for the Fresnel information. I don’t think the stuff I had looked at before had had images.

You’re most welcome!