Types of Grids

The first issue of any visualization is the type of grid in use. Most grids fall into one of two basic categories.

Structured Grids

Structured grids get their name from their nature of having a structure implicitly defined by the arrangement of the data. Structured grids have a basic rectangular matrix structure that makes storage and use easy as integer offsets (typically named I, J, and K) can be used to access individual data points. Data points are arranged into rectangular or cubic structures by simply connecting them to their neighboring I, J, and K cells.

Within structured grids there are several subtypes:

Unstructured Grid
Unstructured Grid

Unstructured Grids

Unstructured grids are the exact opposite of structured grids, where the connectivity between points must be explicitly defined for every set of points. This makes them significantly more difficult and complex, and the nice relationships between neighboring cells or edges is no longer automatic and must be constructed manually. However, they are much more flexible in their ability to define complex shapes because they have no constraints on their arrangement.

Unstructured grids are typically defined as points and cells. Cells are collections of points to define basic 2-D or 3-D primitives such as triangles, cubes, and tetrahedra.

Specialty Grids

There is also an emerging field of specialty grids. Consisting of various combinations of structured and unstructured, they are a widely researched area with wide promise in future work. Typically they boast specific features such as hierarchical information or multi resolution.

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