A heightfield plugin has access to Geofrac's terrain/heightfield buffer. It can modify it, replace it, and/or create a new one. The following are all of the heightfield plugs currently supported by GeoFrac2000.
| Plugin Name | Date Updated | Description |
| Spectral Synthesis | April 1999 | Spectral synthesis is an extremely fast method (also known as Fourier filtering) for generating heightfields. This is the spectral representation of samples based on the approximation of Fractional Brownian motion. This method is probably the best and most accurate representation of realistic landscape generation, and the algorithm allows for an infinite number of possibilities. The plugin provides several preset values that target specific types of landscape formations, but you can experiment with the settings to produce your own unique landscapes. |
| D.E.M. | April 1999 | Digital Elevation Maps are data files comprised of height information obtained from satellite or high airial photography. These are obviously the best source and method for generating realistic landscapes, simply because they are real! The plugin is quite simple in that it reads .dem files and converts them into GeoFrac's internal representation. Now, USGS GeoData has converted all their .dem files into SDTS format, but the SDK comes with conversion tools that create GeoFrac proprietary data files from SDTS files. The plugin will read these files as well. |
| Image To Heightfield
(I-2-H) |
April 1999 | Not much to say here...Basically, this plugin reads in images (in several formats) and converts them to standard grayscale images, which in turn are converted into heightfields based on grayscale intensities.This might cause some of you to think that this is a good way to convert 2D images of 3D objects into 3D. Let's put that one to rest right now...IT'S NOT. Keep in mind that bright values (i.e. hilights) represent extremely high altitudes, and dark values (i.e. shadows) represent extremely low altitudes. Overhead 3D views look great, however, once a horizon line exists in the view, the visual representation of the original picture is lost. This plugin was written so that I could import heightmaps generated by other programs, but I'm sure there are many other uses for it. Try it and let me know!!! |
| Perlin Noise Show Me! |
April 1999 | Ah yes, Mr. Perlin...This is a gem of an algorithm that uses predictable random numbers to generate heightfields. It's predictable in that it has self-similarities. Meaning, you can zoom in on a particular region, and regenerate that region with higher resolution, at the same time maintaining the original shape and structure. This is Noise generation at its finest. The plugin needs a lot of work, and I don't like it as much as the Spectral Synthesis plugin, but filters (especially Erode) tend to work better on Perlin noise. I have a feeling that once I get this working properly, it will become my favorite. |
Terragen Plugin
All information on the Terragen plugin can be found in the section titled "GeoFrac & Terragen".
