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- _____________________________
-
- Appendix C
- Vistapro User Manual
- _____________________________
-
- GLOSSARY OF TERMS
-
-
- AI
- --
- Artificial Intelligence. The ability of a program to
- incorporate expert judgment enabling it to imitate intelligent
- decision making.
-
- Aliasing Artifacts
- ------------------
- Objects which appear in a landscape which are not derived from
- mapping data. They may reside in the data or they may be formed
- as a result of the program.
-
- Caldera
- -------
- The crater at the top of a volcano.
-
- DEM
- ---
- Digital Elevation Model is a model of a landscape reduced to
- three dimensional digital coordinates.
-
- Digital Elevation Model
- -----------------------
- Digital Elevation Model is a model of a landscape reduced to
- three dimensional digital coordinates. Abbreviated: DEM.
-
- Dithering
- ---------
- A program function which blurs the boundaries between polygons
- in order to more closely simulate realism in landscape
- creation.
-
- Fat Polys
- ---------
- Foreground polygons which are relatively larger than the
- polygons in distant scenes. Fat Polys are a function of
- perspective and the accuracy of the data being rendered.
-
- Fractal
- ------
- Fractional dimension. Most math deals with whole numbered
- dimensions. One dimension is a point. Two dimensions are a
- line. Three dimensions are a solid. Four dimensions are a
- space-time solid, and so on. Fractals deal with non-whole
- numbered dimensions, and fractal geometry is capable of
- producing pictures which are remarkably similar to natural
- phenomena - particularly geological shapes.
-
- Gadget
- ------
- A gadget is a black box which contains numerical or textual
- information. It shows Vistapro settings and allows modification
- of these settings. See the Gadget section in the Graphical User
- Interface portion of Chapter 2 of this manual on page 2-10.
-
- Haze
- ----
- The atmospheric occlusion that increases with the distance
- between the eye and the target.
-
- PCX
- ---
- A standard graphic file format used by computers.
-
- Jaggies
- -------
- Partial polygons which produce jagged lines often at the ridge
- line of a landscape and sometimes in the foreground. Jaggies
- distort the realism of a scene.
-
- Olympus Mons
- ------------
- A volcano on Mars. Olympus Mons is an extremely vast feature.
- The base of the volcano covers an area the size of Nebraska.
- Olympus Mons also has a feature which is unique within the
- solar system. The base of the volcano is well within the thin
- atmosphere of Mars. The peak of the volcano is virtually above
- the Martian atmosphere allowing launch to orbit by magnetic
- acceleration. A tramway could be constructed from the base of
- Mons Olympus to the top of Mons Olympus. Liquefied carbon
- dioxide, water, hydrogen, and oxygen (condensed from the
- atmosphere) could then be transported for magnetic rail launch
- into orbit at the top. A return from space could be
- accomplished with aero-braking. Therefore, Mons Olympus could
- become the basis for a Martian space transportation system
- which did not require rockets.
-
- Polygons
- --------
- The basic geometric units with which Vistapro renders
- landscapes. A polygon is a two dimensional shape having at
- least three linear sides.
-
- Ray Tracing
- -----------
- A method of image generation where a hypothetical ray of light
- is projected, reflecting off the target and ultimately
- colliding with the camera.
-
- Topography
- ----------
- Science of drawing maps representing the surface features of a
- region.
-
- Topology
- --------
- The study of the surface features of a region.
-
- USGS
- ----
- United States Geological Survey. The USGS has created three
- dimensional maps of much of the United States, some undersea
- landscapes, and some extra terrestrial landscapes. Much of the
- work done by USGS is in the public domain and can be adapted
- for display by Vistapro.
-
- XYZ Coordinates
- ---------------
- XYZ coordinates simply refer to the three dimensions necessary
- to define a solid object. By translating the topology of a
- landscape into XYZ coordinates, the three dimensional
- topography can be stored in digital format and can be easily
- manipulated by Vistapro's landscape rendering engine.
-
-
- *** End of Appendix C ***
-