Texture2DDoc.tioga
Michael Plass, February 3, 1986 12:24:34 pm PST
Texture2D
CEDAR 6.0 — FOR INTERNAL XEROX USE ONLY
Texture2D
Ken Perlin, Michael Plass
© Copyright 1985 Xerox Corporation. All rights reserved.
Abstract: A program for creating various 2-dimensional textures (as AIS files), using methods developed by Ken Perlin.
Created by: Ken Perlin, Michael Plass
Maintained by: Michael Plass <Plass.pa>
Keywords: texture, AIS, bark, drops, marble, rock, smoke
XEROX Xerox Corporation
Palo Alto Research Center
3333 Coyote Hill Road
Palo Alto, California 94304
For Internal Xerox Use Only
Philosophy
Texture2D uses the philosophy that one way to make a picture is one pixel at a time. The idea is to define a function of x and y that returns the intensity of the given pixel. See Ken Perlin's paper in the 1985 SIGGRAPH proceedings for more details.
The workhorse in all these texture generators is a function that generates a band-limited noise function of the input coordinates. The individual generators call this one or more times, combining the results in various ways.
Use
The user interface is kind of funky. The command
Texture2D
defines a bunch of aliases for invoking the program in various ways using the StatementInterpreter. Some of these are:
T2UseDunnView - use DunnView to display results (requires color display)
T2UsePreview - use preview to display results (default)
T2UseQuiet - don't try to display results automatically
T2Boost - Changes contrast of KPTemp.ais so it uses the full scale of available values
T2Save shortname - Copies shortname.ais from KPTemp.ais
T2Do
mytype
myres - does the picture
mytype at a size of
myres pixels square.
See Texture2DImpl.Surface for a list of possible values for mytype. Results depend on the setting of various global variables in Texture2DImpl.
T2Bark, T2Drops, T2Marble, T2Rock, T2Smoke, T2Elevation
Canned versions of textures at a size of 300 pixels square.
Hints
When playing with various parameters, use a low resolution to keep the waiting time tolerable. About 50 to 100 pixels square is good on a Dorado. If you have a DLion, I recommend signing up for a Dorado. Then when you are satisfied, start it up at a higher resolution and go do something else while it cranks away.
Be brave about changing the program to make it do what you want.
Wedge
WedgeImpl and Wedge.load provide functions and a command for making simple gray wedges and vignettes.
Wedge fileName functionID dots lines aVal bVal cVal
fileName is the name of the output file
dots, lines specify the output size
functionID is the name of a function in WedgeImpl (e.g. LinearX, LinearY, QuadY, Vignette)
aVal, bVal, cVal are parameters; the interpretation depends on the function invoked.