Scalable Height Field Self-Shadowing


We present a new method suitable for general purpose graphics processing units to render self-shadows on dynamic height fields under dynamic light environments in real-time. Visibility for each point in the height field is determined as the exact horizon for a set of azimuthal directions in time linear in height field size and the number of directions. The surface is shaded using the horizon information and a high-resolution light environment extracted on-line from a high dynamic range cube map, allowing for detailed extended shadows. The desired accuracy for any geometric content and lighting complexity can be matched by choosing a suitable number of azimuthal directions. Our method is able to represent arbitrary features of both high- and low-frequency, unifying hard and soft shadowing. We achieve 23 fps on 1024x1024 height fields with 64 azimuthal directions under a 256x64 environment lighting on an Nvidia GTX 280 GPU.


Full paper, 1.6 MB, 9 pages
        Computer Graphics Forum (Proc. Eurographics Conference 2010)
        Winner: 3rd Best Paper
Also featured in a popular Finnish computer magazine, MikroPC issue 11/2009 (page cap)

Bibtex reference

Higher resolution paper images:
uniform lighting (1.2 MB)
hard and soft shadows (2.3 MB)
lighting resolution (3.7 MB)
azimuthal directions (7.1 MB)
2048x2048 terrain (2.8 MB)

Conference presentation slides, 18 MB

Screen captures

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Video demonstration

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Download the video (.mov, h264, 1080p24) 357 MB.