Rendering in Parallel -- PVMPOV
Presentation by Ronald Blaschke (11/02/1999)
Rendering with POV-Ray
The basics of raytracing
POV-Ray (=Persistence of Vision)
- official versions for various platforms
- free source available
- maintained by the POV-Ray Team (http://www.povray.org/)
- serial program
- previous scene, 640x480: 4 hours 40 minutes on SGI O2
What is PVMPOV?
PVMPOV = PVM + POV-Ray
- Brad Kline, Cray Research, Inc.
- Andreas Dilger (http://www-mddsp.enel.ucalgary.ca/People/adilger/povray/pvmpov.html)
- Harald Deischinger
- Jakob Flierl
- Embarrassingly Parallel Problem
- Similar to the mandelbrot set. We have
- x by y independent pixel
- an unknown amount of calculation per pixel.
- blocksize, x by y pixel (Default: 32x32)
- #Tasks, n (Default: #Hosts)
Only n/2 spawns must be sucessful.
Block is reassigned if slave is slow.
Speedup = (exec time using 1 proc)/(exec time using n procs)
Image size: 640x480 pixel
Time for serial program on 1 SGI O2: 16800 seconds
16 SGI O2s for parallel test
Theoretical Speedup: 14 (12 full SGI O2s + 4 half SGI O2s, because already busy with 1 process)
|Block size||Blocks/Image||Time (sec)||Speedup|
The example picture, "First Strike at Pearl," was created by N.B. (firstname.lastname@example.org) and Glenn McCarter (email@example.com) and can be found at http://www.geocities.com/SoHo/Workshop/9193/index.html.
Raytracing Introduction pictures are taken from JK's POV-Ray pages at http://members.tripod.com/~klatte/pov/raytrace.html.