Enhanced Graphics for Extended Scale Range is a computer program for rendering fly-through views of scene models that include visible objects differing in size by large orders of magnitude. An example would be a scene showing a person in a park at night with the moon, stars, and galaxies in the background sky. Prior graphical computer programs exhibit arithmetic and other anomalies when rendering scenes containing objects that differ enormously in scale and distance from the viewer.
The present program dynamically
repartitions distance scales of objects in
a scene during rendering to eliminate
almost all such anomalies in a way compatible
with implementation in other
software and in hardware accelerators.
By assigning depth ranges correspond -
ing to rendering precision requirements,
either automatically or under
program control, this program spaces
out object scales to match the precision
requirements of the rendering arithmetic.
This action includes an intelligent
partition of the depth buffer ranges
to avoid known anomalies from this
source. The program is written in C++,
using OpenGL, GLUT, and GLUI standard
libraries, and nVidia GEForce
Vertex Shader extensions. The program
has been shown to work on several computers
running UNIX and Windows
This program was written by Andrew J. Hanson and Philip Chi-Wing Fu of Indiana University for Goddard Space Flight Center. For further information, contact the Goddard Innovative Partnerships Office at (301) 286- 5810. GSC-14819-1