Learning Objectives:
- Identify GIS application domains in which true 3-D models of natural phenomena are necessary
- Illustrate the use of Virtual Reality Modeling Language (VRML) to model landscapes in 3-D
- Explain how octatrees are the 3-D extension of quadtrees
- Explain how voxels and stack-unit maps that show the topography of a series of geologic layers might be considered 3-D extensions of field and vector representations respectively
- Explain how 3-D models can be extended to additional dimensions
- Explain the use of multi-patching to represent 3-D objects
- Explain the difficulties in creating true 3-D objects in a vector or raster format
- Differentiate between 21/2-D representations and true 3-D models