ESLPV: Enhanced subsurface light propagation volumes

In this paper, we present an enhanced subsurface light propagation volumes (ESLPV) method for real-time rendering of translucent materials. Our method is an extension of the subsurface light propagation volumes (SSLPV) (Proceedings of the ACM SIGGRAPH Symposium on High Performance Graphics, HPG '11, pp 7-14 ACM 2011) technique. We improve the SSLPV by incorporating a single-scattering framework that uses the same spherical harmonics (SH) storage structure as the SSLPV. The new single-scattering technique deposits radiance as SH coefficients during a ray marching procedure. The final result is rendered using a ray tracer with importance sampling along the camera ray. This framework also enables the ESLPV to render refractive objects. In addition, we also propose a distance transform optimization that can remove the unnecessary computations during the propagation cycle of LPV (Proceedings of the 2010 ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games, I3D '10, pp 99-107 ACM 2010) based methods. A hierarchical propagation process is also proposed to render highly translucent materials. Similar to the SSLPV, our ESLPV method contains no precomputations, and has low storage requirements that are independent of the mesh size.