Viewing a terrain in ArcMap is similar to viewing other data types. There’s a terrain layer that you can turn on and off in the table of contents (TOC). It has a Layer Properties dialog to control display parameters. The Symbology tab on this dialog is identical to TIN layers.

The terrain will retrieve measurements from the database for the pyramid level associated with the current display scale. The measurements are triangulated on the fly and drawn to the screen. When going from a coarser pyramid levels to more detailed levels, only the additional measurements needed to get to the higher-detail pyramid level are retrieved and added to the triangulation.

The terrain overview is the coarsest representation of the terrain. It’s coarser than the lowest level of detail (LOD) pyramid specified when the terrain was defined. The overview is used by default when the layer is zoomed out to full extent or beyond. This is used to speed up rendering. Use of the overview representation can be turned on and off from the Display tab of the terrain’s Layer Properties dialog. You can also apply a point limit from this tab. The use of a limit tells the terrain layer to downgrade its display resolution if the current environment (that is, display extent, scale, and pyramid definition) would require too many measurement points. This helps maintain display performance at the cost of not always honoring the terrain’s original pyramid display definition. When the resolution has been downgraded, an asterisk is displayed next to the terrain layer’s name in the TOC. By default, a point limit of 800000 is used.