Graphics Programs Reference
In-Depth Information
Figure 6. A 3-D construction of a topographic surface containing a stream that mimics the 2-D graphic
from the textbook. The blue prims illustrate the movement down slope.
Upon completion of the exercise the student
will be able to…
cubic shape of some of the basic primitive build-
ing objects the 3-D building tools provide. This
is not unlike the realization that cinematography
instructors have about the capabilities to film inside
Second Life (called machinima) such as place-
ment, staging, lighting, camera movement, etc.
In the sort of blocks world idea of maps that I
assumed in my first example, where square por-
tions of the earth are categorized as belonging to
one topographic level or another, one can extend
the idea for more exercises. For example, grid
cell based GIS also characterizes individual grid
cells by one type or another (e.g. different land
use types). In my second example, I wanted the
students to experience how the computer would
decide which grid cells would be coded a particular
category when they are overlaid on a traditional
map. This is a common task in GIS where a clear
grid would be laid down on top of a map so that
each grid cell gets a unique category. To do this in
1. Create a 3-D visualization of a topographic
surface as represented by a grid-cell based
GIS
2. Create a 3-D visualization of a topographic
surface with a stream running through the
middle.
3. Color code the movement of a fluid along
the stream channel that you produced.
4. Use textures on the grid cell prims to illus-
trate the movement of fluid from the upper
surface toward the stream.
5. Explain the limitations of representing sur-
faces using grid cells.
The conversion from course content to Second
Life exercises requires recognition of the physical
shape of GIS data cells and their relationship to the
Search WWH ::




Custom Search