GISMO USER MANUAL


CONTENTS

  1. Introduction
  2. Installation
  3. Getting Started
  4. Using GISMO
    1. Making new terrain maps
    2. Manipulating terrain maps
    3. Exiting GISMO

INTRODUCTION

GISMO, or Geographic Information Systems MOdeller, is a map visualization tool designed to aid the user in viewing detailed terrain maps of a given area. GISMO presents an easy-to-use Graphical User Interface (GUI) for the viewing and manipulation of these maps. GISMO must be used in an environment that supports OpenGL. Within the Computer Science Department, only SGI machines support OpenGL, so GISMO has only been tested on these machines.

To use GISMO, the user needs to supply a general map (or "thumbnail map") of the area of interest, as well as files of data points for that area taken in a geographic survey. The user may then select any arbitrary subregion of the thumbnail map by outlining a box on the thumbnail map with the mouse. GISMO will then display in a new window a detailed terrain map of that subregion, constructed from the files of data points. This terrain map will give a two-dimensional, "bird's-eye-view" of the subregion, and indicate the elevations of the land by using a system of gradated colors. For instance, land that is at sea-level might appear dark green, a high mountain peak white, and a low valley light green.

GISMO is currently being developed to handle a first-run test case: the area of interest is the North Shore Mountains of the Vancouver area. Our client has supplied the necessary topographical data points. Additionally, the user may specify another area of interest and provide the necessary data files.


INSTALLATION

Installation of GISMO involves relatively few steps. Begin by either downloading all of the .C and .h files and the link labeled "Sample Data" listed on the page labeled Project Files. Alternatively, you may also download the file located at the bottom of the page named all.tar. If you choose the latter option, untar the files by typing "tar zxvf gismo.tar.gz" on the command line. This will give you all the source and header files required by GISMO in a directory called gismo/.

Next decompress the file labeled "data.tar.gz" by typing "tar zxvf data.tar.gz" at the command line, in the gismo/ directory. This will give you some sample data files to run GISMO on.

Now, edit the Makefile to reflect the location of your FLTK SGI lib/ and include/ directories.  Build GISMO by typing "make" at the command prompt.  You can do an optional 'make install' if you want to install the GISMO binary in /usr/local/bin.


GETTING STARTED

Getting started with GISMO is fairly simple. At the command line prompt, type
%  ./gismo < mapname >
where < mapname > is a substring occuring in all of the file names which determine the thumbnail map. For example, "./gismo 92g" will get the user started with the Vancouver map. A window will then appear, displaying the thumbnail map. You are now ready to begin using GISMO.


USING GISMO

MAKING NEW TERRAIN MAPS

Once you have the thumbnail map, you can begin selecting subregions of it that you wish to view by holding down the left mouse button and dragging the mouse left or right (to increase the subregion's area horizontally), and up or down (to increase the subregion's area vertically). After you have made a box whose size is to your liking, release the mouse button to produce a terrain map of the subregion you have chosen.

Selecting a subregion

The terrain map will appear in a new window. The dimensions of the map within this window will always be of a fixed size: so if you choose a really large subregion, GISMO will compress the map to fit in those dimensions; if you choose a really small subregion, GISMO will likewise expand the map. Thus, the smaller the subregion you choose, the more detailed the terrain map GISMO produces.

You may continue to select new subregions by tracing new boxes with the mouse on the thumbnail map; GISMO will open a new window for every subregion you select. If you decide to view a new region, you must quit GISMO (see Exiting GISMO) and specify a new region on the command line (see Getting Started).

MANIPULATING TERRAIN MAPS

In order to exaggerate the differences between various elevations on a terrain map, you may choose to multiply all the data points' z-coordinates by a constant factor. To do this, locate the box at the bottom of the window labeled "Z FACTOR", and use the right arrow to increase the factor, or the left arrow to decrease it. As you adjust the factor, the map will be redrawn within the window with the new elevations and new coloring.

Zooming in on a Subregion

EXITING GISMO

To exit GISMO, click on the button labeled "Quit" in the top right corner of the thumbnail map viewer. You may also exit GISMO by simply closing the window which contains the thumbnail map. When you exit GISMO, all windows containing terrain maps will also be closed. However, you may close any terrain windows without affecting the program.


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