Download presentation
Presentation is loading. Please wait.
Published byHannah Austin Modified over 8 years ago
1
Computer Graphics: Programming, Problem Solving, and Visual Communication Steve Cunningham California State University Stanislaus and Grinnell College PowerPoint Instructor’s Resource
2
Nonpolygon Graphics Techniques that lie generally outside the OpenGL graphics model
3
A Number of Techniques… Ray tracing Ray casting Iterated function systems –Contraction mappings –Generating functions –Mandelbrot and Julia sets
4
Ray Casting Create a “virtual screen” and generate a ray from the eye point through each point on the screen Compute what each ray hits in the screen, and color the pixel the appropriate color
5
Ray Casting (2) The value of ray casting lies in being able to compute whatever the ray hits This may be a computation of a single hit or may involve many things along the ray, as in volume rendering
6
Ray Tracing Ray tracing starts with ray casting, but includes the possibility of generating new rays when the original ray hits something –Reflection rays –Refraction rays –Rays to light sources
7
Ray Tracing (2) Ray tree, with reflection R, refraction T, and light L rays shown Example ray-traced image, from POVRay
8
IFS - Contraction Mapping Generate a number of random points (in either 2D or 3D space) Apply a recursive stochastic function that maps the point into other points After a given number of steps, stop the recursion and plot the points
9
Contraction Mappings (2) Example: Sierpinski Gasket Example: fern
10
IFS - Generating Functions Blancmange functionDragon curve
11
IFS - Mandelbrot and Julia Sets Mandelbrot setJulia set
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.