parallel ray tracer computer systems lab presentation stuart maier
Post on 14-Jan-2016
233 Views
Preview:
TRANSCRIPT
Parallel Ray Tracer
Computer Systems Lab PresentationStuart Maier
Abstract
Computer generation of highly realistic images has been a difficult problem. Although there are algorithms that can generate images that look
essentially real, they take large amounts of time to render. This project explores ways of
distributing that onto multiple computers, in order to speed up the process.
Graphics Background
Many different algorithms Most unrealistic
Real-life based algorithms developed Ray tracing most important
Shoots rays from camera Interact with intersected objects Local illumination
Ray Tracing
Rays shoot through screen
Rays seek light sources
Phong shading
Image from Wikipedia.
Phong shading
Formula for calculating light
Graphics cont.
Photon mapping Two pass algorithm Creates photon map Ray tracing afterwards Biased Still not realistic enough
Graphics cont.
Path tracing Rays don't seek light Rays can:
Find light Be absorbed Be transmitted
Spectral rendering Full spectrum of colors
Spectral Rendering
Complete color space RGB part illuminated Many different colors
can create the same RGB value
Image from Wikipedia.
Parallel Background
BOINC Multiple independent clients No interclient communication Clients barely talk with server
Splitting data Pixels are divided up among clients
Design
Written in C with MPI and OpenGL libraries Currently implements a parallel ray tracer with
Phong shading Five components
Main Renderer Object Vector XML
Main
Runs the entire show Talks with MPI and OpenGL Starts up the renderer Passes off to the Renderer component
Renderer
Holds information about the scene Renders the scene Performs the high-level ray calculations
Object
Information about objects Calculates ray-object intersections
Vector
Generic library Creates 3-D vectors and processes them Used for spatial and color calculations
XML
First component called after Main Reads in the scene file Passes off information to Renderer
top related