Computers in Geology - Fall 2006

This is some reference information for the 3D visualization portion of this class.

3D Viewer Software for Your Computer

Optional: If you have your own computer with Microsoft Windows or Apple MacOS, you may want to get a copy of the free Cortona VRML viewer. This lets you view 3-dimensional objects using your web browser. To test that it installed correctly you can go to http://simkin.asu.edu/holodraw/example/polybox.html and select the link that says polybox.wrl. You can drag the picture with your mouse to view it from different angles.

Monday 2006-11-06: Extracting and Processing Data

We will walk through the steps of making 3D models from numeric data. My home directory on kaibab is /export/home4/msimkin and you can look there for the things I make during class.

Unix Control Keys

Here's a couple handy Unix control-key combinations you may need:

• Control-C (Cancel)
  Use this if you are running a program that is taking too long or doing the wrong thing and you need to stop it. If your program was writing to an output file when you cancelled it, the file is probably only half done, and you should not expect it to be usable until you fix the problem and run the program again.
• Control-D (Done)
  When a program is reading standard input from your terminal, you can type line after line of data and the program will just keep wanting more. Press Enter after the last line of data then press Control-D to indicate that you are Done entering data.

Unix Commands

The Unix command to fetch a data file (or anything) from a website was:

After Class Monday 2006-11-06

You can review the presentation slides for reminders of what we did.

Your project assignment is to create a 3D image from some data that would be meaningful when viewed in three dimensions. Here are some links for your project:

• http://holodraw.org/
  This software has already been installed on our Unix computer "kaibab". However you should review the website for helpful info. (The software is free, so you can download a copy for your own computer if you want.)
• HoloDraw Documentation
  Note especially the links at the bottom for detailed information about each HoloDraw program.
• HoloDraw Examples
  The Tutorials section starts with a simple line drawing and works up to more complicated examples. Each example shows you the HoloDraw instructions and the Unix script that made the 3D image. Refer to these when you need hints!
• How to Make a 3D Drawing using HoloDraw
  Step by step tutorial to get you started.
• How to Draw a Sphere
  Shows how to work with latitude and longitude in HoloDraw.

Your first attempt at creating a 3D image is due at the beginning of Wednesday's class. You do not have to have a working 3D image at this time, but you must have made a significant effort.

Wednesday 2006-11-08: Troubleshooting

Your first attempt at creating a 3D image is due at the beginning of class. Things almost never work right the first time you create a program. I do not expect you to create a complete 3D image right away. Of course, if you do, that's great! But if you encounter some difficulties, we will discuss them in class Wednesday, and try to find solutions.

After Class Wednesday 2006-11-08

Return to your 3D image project and get it working, using the troubleshooting tips discussed in class. Your 3D image and the script and data file(s) that made it must be posted to your homework folder by 8:00 AM Monday 2006-11-13.

Written by Marvin Simkin Filename index.html Last updated November 4, 2006