Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)

Legacy Department

Computer Science


Geist, Robert M

Committee Member

Westall , James M

Committee Member

Duchowski , Andrew T

Committee Member

Woodard , Damon L


Real-time rendering of large-scale, forest ecosystems remains
a challenging problem, in that important global illumination effects,
such as leaf transparency and inter-object light scattering, are
difficult to capture, given tight timing constraints and scenes
that typically contain hundreds of millions of primitives.
We propose a new lighting model, adapted from
a model previously used to light convective clouds and other
participating media,
together with GPU ray tracing, in order to achieve these global illumination
effects while maintaining near real-time performance. The lighting
model is based on a lattice-Boltzmann method in which
reflectance, transmittance, and absorption parameters are
taken from measurements of real plants. The lighting model
is solved as a preprocessing step, requires only
seconds on a single GPU, and allows
dynamic lighting changes at run-time.
The ray tracing engine,
which runs on one or multiple GPUs,
combines multiple acceleration structures to achieve
near real-time performance for large, complex scenes.
Both the preprocessing
step and the ray tracing engine make extensive use of
NVIDIA's Compute Unified Device Architecture (CUDA).