Viewing Complex Environment with Hierarchical Light Fields
Xing Chen,
Lucas Pereira, and
Pat Hanrahan, Stanford University
Submitted to SIGGRAPH '98
Abstract:
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.
Paper:
xcchen@graphics.stanford.edu