Screen-Space Subsurface Scattering, A Real-time Implementation Using Direct3D 11.1 Rendering API

Abstract: Context Subsurface scattering - the effect of light scattering within a material. Lots of materials on earth possess translucent properties. It is therefore an important factor to consider when trying to render realistic images. Historically the effect has been used for offline rendering with ray tracers, but is now considered a real-time rendering technique and is done based on approximations off previous models. Early real-time methods approximates the effect in object texture space which does not scale well with real-time applications such as games. A relatively new approach makes it possible to apply the effect as a post processing effect using GPGPU capabilities, making this approach compatible with most modern rendering pipelines. Objectives The aim of this thesis is to explore the possibilities of a dynamic real-time solution to subsurface scattering with a modern rendering API to utilize GPGPU programming and modern data management, combined with previous techniques Methods The proposed subsurface scattering technique is implemented in a delimited real-time graphics engine using a modern rendering API to evaluate the impact on performance by conducting several experiments with specific properties. Results The result obtained hints that by using a flexible solution to represent materials, execution time lands at an acceptable rate and could be used in real-time. These results shows that the execution time grows nearly linearly with consideration to the number of layers and the strength of the effect. Because the technique is performed in screen space, the performance scales with subsurface scattering screen coverage and screen resolution. Conclusions The technique could be used in real-time and could trivially be integrated to most existing rendering pipelines. Further research and testing should be done in order to determine how the effect scales in a complex 3D-game environment.