Subsurface Scattering (SSS) or Subsurface light transport (SSLT) is a physic light behavior when it penetrates a translucent surface, being scattered and bouncing in the interior of an object in a certain depth depending on the material characteristics to finally get out, making it glow, softening the shapes and making it have brighter colours but also, showing the inner characteristics of the material, in the skin’s case, veins, muscles or bones.
The next video explains the different behaviors the light has with materials depending on the properties of the object:
As video game and film industries’ projects have become more and more realistic, in order to try to break through the uncanny valley, one of the most important features that an object or a realistic living have needed to incorporate has been a SSS systems that accurately emulate real light behavior. Technology has also evolved to achieve better and better results, being Separable Subsurface Scattering one of the latest research in this matter:
Light and its interaction with materials has been always a very resource consuming features for the rendering process. Therefore, in the case of videogames that have to reproduce this realistic rendering effect in real-time have become a real challenge. Game engines like Unreal or Unity have already developed tools that emulate this effect in real time. Nevertheless, due to the real-time rendering and current hardware technology constrains it is still not perfect and will be improved in the future. Even though, this has entailed a great step in the good direction allowing game companies to create very believable characters and astonishing environments never imagined before.
During this course I have learnt the basics of Unreal engine. Therefore I will center my effort in knowing how to use SSS in this engine. In the next video is explained the process to use SSS and create photorealistic character materials in Unreal:
In my opinion, learn how to create subsurface materials is a very important feature that all 3d game artist should know. I have discovered along this course that shaders represent a big percentage of the quality of the final model presentation. Nevertheless, due to time and planning constraints I didn’t have time to learn how to apply SSS materials to my models but I received very good feedback, advices and references to apply it in future models. I am very happy with the result of my project but I can’t imagine how good my characters would look if I would have used SSS on them. Therefore, I will study and practice how to do this kind of materials to include them in my workflow in order to create better quality models.
cryptosporidium136 (n.d.) [UNITY] Realtime Subsurface Scattering [Online video]. Available from: <https://www.youtube.com/watch?v=NJq1meIXtb0 >. [Accessed 18 August 2017]
Two Minute Papers (n.d.) Separable Subsurface Scattering | Two Minute Papers #66 [Online video]. Available from: <https://www.youtube.com/watch?v=72_iAlYwl0c >.[Accessed 18 August 2017]
Jimenez, J., Zsolnai, K., Jarabo, A., Freude, C., Auzinger, T., Wu, X.C., der Pahlen, J., Wimmer, M. and Gutierrez, D., 2015, September. Separable subsurface scattering. In Computer Graphics Forum (Vol. 34, No. 6, pp. 188-197).
Bobby Chiu (n.d.) The 4 Main Types of Subsurface Scattering [Online video]. Available from: <https://www.youtube.com/watch?v=GkjvYSbGHg4 >.[Accessed 18 August 2017]
Unreal Engine (n.d.) Photorealistic Character Project | Project Spotlight | Unreal Engine [Online video]. Available from: <https://www.youtube.com/watch?v=ktNlxiTir6I >.[Accessed 18 August 2017]