Real-Time Volumetric Shadows using 1D Min-Max Mipmaps
Name
Durand-Real-time Volumetric.pdf
Size
15.4 MB
Format
Adobe PDF
Checksum (MD5)
933a469ecd3e524136d835baa8b42fc8
Author(s)
Chen, Jiawen
Baran, Ilya
Durand, Fredo
Jarosz, Wojciech
Date Issued
February 2011
Journal
Symposium on Interactive 3D Graphics and Games (I3D '11)
Publisher
Association for Computing Machinery (ACM)
Citation
Jiawen Chen, Ilya Baran, Frédo Durand, and Wojciech Jarosz. 2011. Real-time volumetric shadows using 1D min-max mipmaps. In Symposium on Interactive 3D Graphics and Games (I3D '11). ACM, New York, NY, USA, 39-46.
Version
Author's final manuscript
Abstract
Light scattering in a participating medium is responsible for several important effects we see in the natural world. In the presence of occluders, computing single scattering requires integrating the illumination scattered towards the eye along the camera ray, modulated by the visibility towards the light at each point. Unfortunately, incorporating volumetric shadows into this integral, while maintaining real-time performance, remains challenging.
In this paper we present a new real-time algorithm for computing volumetric shadows in single-scattering media on the GPU. This computation requires evaluating the scattering integral over the intersections of camera rays with the shadow map, expressed as a 2D height field. We observe that by applying epipolar rectification to the shadow map, each camera ray only travels through a single row of the shadow map (an epipolar slice), which allows us to find the visible segments by considering only 1D height fields. At the core of our algorithm is the use of an acceleration structure (a 1D minmax mipmap) which allows us to quickly find the lit segments for all pixels in an epipolar slice in parallel. The simplicity of this data structure and its traversal allows for efficient implementation using only pixel shaders on the GPU.
MIT Department
Massachusetts Institute of Technology. Computer Science and Artificial Intelligence Laboratory
Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Terms of Use
Creative Commons Attribution-Noncommercial-Share Alike 3.0
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1145/1944745.1944752
