A FRAMEWORK FOR GLOBAL ILLUMINATION IN ANIMATED ENVIRONMENTS
Jeffry Nimeroff, Julie Dorsey, and Holly Rushmeier
Presented at the 6th Annual Eurographics Workshop on Rendering,
Dublin Ireland, June 12-14 1995
We describe a new framework for efficiently computing and storing
global illumination effects for complex, animated
environments. The new framework allows the rapid generation of
sequences representing any arbitrary path in a ``view space''
within an environment in which both the viewer and objects
move. The global illumination is stored as time sequences of
range images at base locations that span the view space. We
present algorithms for determining locations for these base
images, and the time steps required to adequately capture the
effects of object motion. We also present algorithms for
computing the global illumination in the base images that exploit
spatial and temporal coherence by considering direct and indirect
illumination separately. We discuss an initial implementation
using the new framework. Results from our implementation
demonstrate the efficient generation of multiple tours through a
complex space, and a tour of an environment in which objects
move.
Sample Animated Sequences
These images and animated sequences illustrate the results
obtained by using our new framework.
Walkthroughs in a Complex Environment
These three sequences show walkthroughs in a 75,000 polygon
environment. All of the images in the sequences were generated at
a resolution of 256x256 pixels by interpolating a set of wide-angle range images. Click here or here
for examples of the 8 base images used for this environment.
- Sequence 1 , moving through the viewspace
and looking off toward the windows on the right.
- Sequence 2 , moving through the viewspace
and looking off to the left.
- Sequence 3 , through the middle of the
view space, looking downward and upward.
Walkthrough in an Animated Environment
This sequence shows a walkthrough of an environment with
two moving boxes. A time series of images was computed at
each of just two base locations. The indirect solution for all
of the base view images were computed by interpolating
between just two indirect illumination solutions for the
environment -- one in the starting configuration and one
in the ending configuration.
Click here for the animation. Note
the change in the shiny reflections from the boxes as they
move relative to the light source. A very simple scheme
was used for the time interpolation. Improved morphing
between the temporal frames is expected to reduce the
fuzziness currently apparent in the sequence.
Click here for a copy of the paper in
gzipped postscript form.
Click here for a copy of the paper in
gzipped Adobe Acrobat form.