Per-Triangle Shadow Volumes Using a View-Sample Cluster Hierarchy
Paper in proceedings, 2014

Rendering pixel-accurate shadows in scenes lit by a point lightsource in real time is still a challenging problem. For scenes of moderate complexity, algorithms based on Shadow Volumes are by far the most efficient in most cases, but traditionally, these algorithms struggle with views where the volumes generate a very high depth complexity. Recently, a method was suggested that alleviates this problem by testing each individual triangle shadow volume against a hierarchical depth map, allowing volumes that are in front of, or behind, the rendered view samples to be efficiently culled. In this paper, we show that this algorithm can be greatly improved by building a full 3D acceleration structure over the view samples and testing per-triangle shadow volumes against that. We show that our algorithm can elegantly maintain high frame-rates even for views with very high-frequency depth-buffers where previous algorithms perform poorly. Our algorithm also performs better than previous work in general, making it, to the best of our knowledge, the fastest pixel-accurate shadow algorithm to date. It can be used with any arbitrary polygon soup as input, with no restrictions on geometry or required pre-processing, and trivially supports transparent and textured shadow-casters.

real-time

alias-free

shadows

Author

Erik Sintorn

Chalmers, Computer Science and Engineering (Chalmers), Computer Engineering (Chalmers)

Viktor Kämpe

Chalmers, Computer Science and Engineering (Chalmers), Computer Engineering (Chalmers)

Ola Olsson

Chalmers, Computer Science and Engineering (Chalmers), Computer Engineering (Chalmers)

Ulf Assarsson

Chalmers, Computer Science and Engineering (Chalmers), Computer Engineering (Chalmers)

Proceedings of the ACM SIGGRAPH Symposium on Interactive 3D Graphics and Games (I3D 2014)

Subject Categories

Computer Engineering

Areas of Advance

Information and Communication Technology

More information

Created

10/7/2017