Improved Ray Hierarchy Alias Free Shadows
Report, 2011

In this article, we introduce and evaluate several new algorithmic improvements to Ray Hierarchies. The improved algorithm is used to produce ray-traced shadows for omni-directional lights in fully dynamic environments. The new algorithmic improvements increase culling rate of the traversal algorithm, in some cases dramatically cutting the number of visited nodes. To evaluate performance, we present a GPU implementation using CUDA, which uses a hybrid breadthdepth algorithm to perform the traversal using bounded memory. The results show that the use of improved cone hierarchies is able to produce high quality shadows quickly – for some scenes in real-time.


Ray Hierachy


Computer Graphics

Ray Tracing


Ola Olsson

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

Ulf Assarsson

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

Subject Categories

Computer Engineering


Basic sciences

Technical report - Department of Computer Science and Engineering, Chalmers University of Technology and Göteborg University

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