Real-time Fur Deformations forFilm-Quality Characters

Abstract: In this thesis, the goal was to get a production ready fur groom to deform with the underlying subdivided and animated surface in real-time. The thesis investigates how to import a fur groom into Unity, how to render it, how to deform it and how to remove the most obvious of artefacts. When it came to rendering the fur, two different methods were investigated: rendering it as poly lines and as view facing triangle strips. Rendering the fur as view facing trian­gle strips was proven to be slower but the visual quality was a lot better. The deforming of the fur was done as transformations following the underlying subdivided surface. The subdivision of the surface was done using the open-source project OpenSubdiv which was found to be a very helpful tool when finding the hair strands positions on the surface. The methods of volumetric velocity smoothing together with Extended Position Based Dynam­ics were used to add hair-to-hair interactions and to simulate the stiffness of the fur. This removed artefacts of when for example bending an arm or a leg and the hair crashed into each other at the cost of performance. The performance of having 0.9 million hairs, built using 10.2 million hair vertices, de­forming with the underlying surface was measured to be around lOms depending on the way it was chosen to be rendered. Adding hair-to-hair interactions to that dragged the performance down to 332ms. As a conclusion, having a production ready fur groom deform with the underlying surface in real-time is possible. The hair-to-hair interactions part looks promising but will need further improvements and investigations to work in real-time for charaders with a lot of fur.