LogInFurtsentum Liechtenstein was kind enough to explain what makes human skin such a tough thing to render.
Furtsentum Liechtenstein was kind enough to explain what makes human skin such a tough thing to render.
Intro
My name is Furtsentum Liechtenstein, and I am an indie game developer – 3D Artist from Greece. In 2011, I started working with Unity Engine for the creation of interactive art projects. At the same time, I become a Unity Asset Store publisher under the name Rispat Momit as I was interested in the production of Environments, Shaders, and Utilities for Unity Engine users.
Some of my most significant assets are “Forces + Simulations,” “Toon Nature,” “Primitives+Basic Shapes Collection,” Wet Shading,” and “LB Holographic Shader.” In my assets, I aim to create not only high-quality content but also to include an idea that will make it more user-friendly and increase productivity. At the same time, I got involved in game developing creating several games like “ADOM,” “White,” “The Annoyance Maker, “Reniat Run“,” although most of them are in an Alpha stage as I lack manpower and the ability to employ a team.
Right now, I am working on “God s’ Margarita” a game that questions the evolution of the human kind, and how progression can fade away inside war and totalitarian regimes.
Human Skin
The rendering of human skin is one of the most triggering and hard to create shadings. It’s ability to absorb light, and the sub scattering makes it complicated and hard to build. Although in my opinion there is something that plays a more critical role in the human skin shading that maybe not everyone has yet realized. That is the fact that human skin also emits hit, something that separates it from any other lifeless object inside a scene. Making something look alive is also another factor. Even if we develop the real-time rendering of skin to reach photorealistic levels, we will still have to deal with body and facial animations. We have a clear example of this in the gaming world of 2017, Not to name names.
My approach to the human skin shader could only be a modification of any other material shading. That is because I have to consider the general impression of the scene regarding colors, shading, atmosphere. Nothing looks worse than the isolation of something either because it is poorly created or because it is focused only on one perspective not taking into account its environment. We can see this even in our real-life societies too. That is why I couldn’t create only one skin shader but a whole new Light-Based shading collection that could share the same principles but support the individuality of every different material.
Shader
In my Light Based Skin shading, I developed a PBR shader that supports sub scattering as well as the ability to control the opacity of the shadow over the skin. Through those utilities, I can control the impression of the surface of the skin, although those are not enough as they make the skin look only like wax. There are much more facts that I had to take into account. The specularity of a surface that absorbs water, the way that sub scattering interacts with the environment’s lights and colors. The emission of hit that we can see only in the areas that the light is hitting multiplied by the Ambient Occlusion. The final result is a shader were every function interact with each other based on my conception of how light works. One more thing I consider while I was creating the shader is to give the developer the ability to have full control over the values of the shader’s functions. This way we can create materials like marble, porcelain, enamel, foliage shading from the same shader.
Performance
Regarding the performance, I built my shader based on Unity’s surface shaders. That way it is compatible with all Unity’s functions and optimizations. For the best results regarding lighting, it is essential to use Reflection and Light probes as well as Real-time GI. In the end, I aim to start something by its most simple form and keep it that way until the end, focusing on the interaction between every single value inside the shader.
Conclusion
Skin shading is one of the most challenging things regarding shading, but I believe that our struggle to make it look super realistic will soon be part of our past. I think that we will soon be focusing on additional ways or rendering and reconstructing reality inside games, especially now that VR is emerging into the market. Modern technology is moving with accelerating rhythms, so I wouldn’t be surprised to see next generation graphics in mobile devices in the next 10 to 20 years or even the ability to integrate a digital environment with the way we construct our dreams.