Viewing Complex Environment with Hierarchical Light Fields

Xing Chen, Lucas Pereira, and Pat Hanrahan, Stanford University

Submitted to SIGGRAPH '98


We propose a hierarchical light field framework in which it is possible to deal with complex environments that cannot be simply represented by a basic 4D (non-hierarchical) light field. The hierarchical light field framework extends the basic light field structure by defining bounds on the region of freespace over which a light field is valid. It consists of multiple light fields hierarchically placed in 3D space, with each light field only sampling part of the scene. By compositing the images from the subset of light fields that are valid for any viewpoint, the viewer is given much more freedom in the range of possible views compared to the basic light field representation. The sampling resolution is hierarchical and view dependent to guarantee efficient sampling, which avoids overrsampling and aliasing during minification. The hierarchy and sampling parameters are generated systematically so that a known lower bound on image quality can be maintained. Also, the rendering time is independent of the scene complexity. Because of these advantages, the hierarchical light field framework is suitable for visualizing complex environments.

In this paper, the advantages of hierarchical light fields are described and analyzed, along with techniques for reduction of light field memory requirements. A detailed description is given of the steps undertaken during generation of hierarchical light fields and the reconstruction process. The capabilities and advantages of the representation are shown by examples of an immersive walkthrough and a 3D fly-around of an object.