3DAD 041 : Rendering skin materials – Paolo Ciccone interviewed on his Reality Plugin

Paolo Ciccone is the creator of the Reality plugin. It’s both for Poser and DAZ Studio and it introduced Physically Based Rendering (PBR) around 2010, when PBR was not that familiar for Poser and DAZ Studio artists. PBR provides more natural looking renders than previous techniques. Reality uses the LuxRender rendering engine.

Download and listen to the podcast session 41

Get training on Reality from our previous webinar sessions

Reality gives a rendering solution that extends DAZ Studio and Poser and is described as providing the most advanced Physics-Based Rendering system in the market.

In the session of the podcast we interview Paolo on using Reality to render skin materials and look at several scenarios of this challenge. These are the questions we asked Paolo:-

1. How can the reality plugin help with gaining realism with skin materials in a render?

2. There are a number of SSS parameters, such as surface thickness, abortion scale and scattering scale. What settings tend to work best for which circumstances?

3. There’s a thread on Runtime DNA that talks about how you spent weeks of development testing thousands of combinations, was that with getting the automatic SSS function correct?

4. Is it possible to make the skin “glow” using Reality? I know there is a “light emission” modifier that might be used since this can be tweaked in any material.

5. You could use a procedural texture to get some interesting patterns on the skin using Reality, without having to use Photoshop. Firstly what’s a procedural texture and how might you apply that in Reality?

6. Since we last spoke in January, you’ve released Reality 4.3. What are the main changes to see in 4.3?

7. You had a surprise phone call this year from a manager at Apple computers. Tell us about that story.

8. You’ve introduced a new Reality Facebook Group. Tell us about this and some of the good things that have come out of this for Reality users.

9. What’s next for Reality?

Resources

Latest version of Reality 4 available here

News on Reality 4 from Paolo’s Pret-a-3D news feed

Reality Artist’s Facebook group

Snippet from the transcript

Paul: Now we’re going to have a focus in this interview on skin. So I think it’s an interesting material and it’s quite a challenge to render realistically until maybe relatively recently. Why do you think that skin has become a challenge for quite a while to represent realistically?

Paolo: That’s a very good topic. Well, it’s a very complex material, first of all. I mean, objectively it’s not like plastic, you know. Plastic is just a shiny surface with a pigment. You see, in fact, the first 3D renderers, they were all pretty much rendering like some type of plastic. And still today whenever a new artist starts working with 3D and that person doesn’t have much experience, the results are often plasticky.

Skin, on the other hand, is a very complex material. It’s a flexible material. It’s made of many different layers and there are many different colors involved. I mean, if you just look at your hand, you know, there is the general skin pigmentation, but then there are the veins, so you can clearly see the bluish tint of the veins. Then, if we look at the knuckles, we see that there are areas that are more reddish than if you look at other parts of the fingers, other parts can be a little darker. And then if you look at the palm of the hand, it becomes more reddish, pinkish. So there are many different hues even in the same spot, in the same area. Skin is made of layers, and then these layers have a certain amount of moisture, and finally we have hair. We look at arms and hands, the back of the hands, or even, you know, the face, or even the nose, has some very fine hairs.

So it’s a complex material and it’s the one thing that we look at the most. Everyday, or at least, we look at it very often. Because as I’m talking to you as a good Italian, I’m moving my hands so I see them. They are in my field of vision. When we are going to the bathroom in the morning, you know, men shave and women might apply makeup. At least we are, you know, combing our hair. I don’t do that much more because I’m getting bald. But, you know, there is a certain amount of personal care that we do routinely everyday, and that is done in front of a mirror. It’s a material we know intimately and, in many case, that is in fact also literal. We may be intimate with other people if we are in a relationship, and that means a lot of contact with skin. I mean, it’s a material if you want to call it that way that we know very well and it’s very hard to fake it because we are familiar and it’s a complex material and therefore the technology needs to really go further than with other materials.

Now, traditionally, 3D renderers, before the PBR, the physics-based rendering revolution that we started having in the last few years arrived, all those 3D renderers were…the, you know, what we called biased renderers, those programs were designed to cut corners. I mean, they were designed to stop rendering whenever the result was good enough. So the inherent design of the program was to not be as accurate as possible, just accurate enough to trick our eye. Well, that can be done with some other materials, but with skin is much, much harder because it is a material that is so complex and it’s so familiar.

So it is really where the advent of PBR that we have been able to simulate what happens with light. Because the scattering of the light under the surface of the skin, that phrasing of the scattering of light under the surface of the skin means literally, you know, it’s another way of talking of subsurface scattering. So that effect… Yeah, we can have subsurface scattering with biased renderers, but the way we render light with PBR is much more accurate, and dye is the extra X percent in the quality of the image that really makes it more credible. I hope I answered your question.

Paul: I think what surprised me when I was reading up this week, I didn’t know that multiple layers in the skin, some layers absorb and scatter light differently. I can assume that each layer, you know, would be at the same, but it doesn’t, you know.

Paolo: No. In fact, if we look at the surface of our skin, most of the surface of our skin is actually dead skin. It’s a little flakes, you know. They say a good portion of dust, you know, the dust we see in the air is actually dead skin. And if you have a cat, it’s also cat fur.

Paul: Extra, yeah. So how can the Reality plugin help with gaining that realism with skin materials in a render?

Paolo: Well, Reality uses a renderer called LuxRender. We were the first of doing it in the Poser and Daz Studio universe, and that was in fact on the 29th of this month we celebrate six years because Reality was released on August 29th, so this interview is really right on time. We started doing that years ago, way before anybody was talking about PBR in the Poser Studio universe. I think actually the Reality is the reason why we have so much widespread PBR rendering today in this market. We popularized the technique, we popularized the idea that you could have a PBR with Daz Studio or Poser. The reason why we were able to do it, that I was able to do it is because I’m using LuxRender, which is an open source renderer….