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Making Illustrations with Geomview

Geomview is a very flexible tool for manipulating 3D images in ways that maximize the information they convey. By changing the arrangement of a scene, the lighting, the shading, transparency and other appearance parameters, the user can easily draw out the most important features of the mathematical object illustrated.

To take full advantage of Geomview, the serious illustrator should begin by reading the Geomview manual (also available in print in the Center library). However, some of the mechanics of using a Geomview image in various ways are outlined below.

Creating a Scene

Geomview scenes are described by OOGL data files. (OOGL stands for "Object Oriented Graphics Language".) However, instead of working directly with the data files, beginners will want to use other software tools to create them. The three best choices for mathematical objects are Mathematica, Maple and FrontStage. Follow the links for help using them.

Playing with Paramters

Once you have a Geomview scene loaded in, there are a number of ways you might enhance it:

Adding Axes -- load the file axes.list from the /u/gcg/ngrap/data/geom directory. Although the axes are unit length, by scaling them separately, you can use them in any size scene.
Adding Text -- the external "Labeler" module, installed on SGI machines, adds 3D text.
Changing Object Appearance -- Often a scene can be dramatically clarified by changing object colors. If the scene lacks visual depth, often drawing the edges in black will help.
Changing Materials Properties -- In the materials panel, there is an option to make an object partial ly transparent. This is often very helpful.

Exporting Image Files

Once you have the Geomview scene you want, you can export is as a PostScript file, a .tiff file, or a Renderman .rib file. For highest quality, and the most flexibility, you should do this on an SGI machine.

A PostScript file is good for including in print documents, as well as making high quality color transparencies and prints with the Tektronix color printer. (For advice about color printing, consult the printing page in the software overview section.)

For electronic media, you will probably want to capture the scene as a .tiff file. You won't want to leave it in this format, but this is a good point to start from. See the section on Working with Images.

For very high quality images, for example, frames for video production, you probably want to use Geomview to create Renderman files. By modifying the Renderman files, one can make near ray-traced quality images. Typically, a user will want to consult with the Center experts about this process.

A thorough discussion of exporting images files from Geomview is contained in the online FAQ guide to Geomview.

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Created: Fri Sep 8 11:39:00 1995 --- Last modified: Jun 18 1996