Terrain dataset troubleshooting

• Problem:

  It appears as though a lot of storage space is required for geometry. This might be slowing things down too.

  Suggestion 1:

  Are m-values enabled unnecessarily? This can happen easily, especially if shapefile-based data was ever involved.

  Suggestion 2:

  Is the resolution set to be more accurate than it needs to be? The default resolution can be excessive.

• Problem:

  The terrain layer does not display.

  Suggestion:

  The terrain may have had a schema change without being rebuilt. Check to see whether the terrain dataset needs to be rebuilt.

• Problem:

  Why isn't a feature class that's inside the dataset available through the Terrain Wizard, or why can't a feature class be added through the API?

  Suggestion:

  Is the feature class versioned? Versioned feature classes cannot be added to a terrain dataset.

• Problem:

  The following error is returned when opening the wizard: "There are no valid feature classes that can participate in a terrain."

  Suggestion:

  The feature dataset is empty or all the feature classes inside the feature dataset are registered as versioned. The proper workflow order is to construct the terrain dataset, have its schema completely defined, then register the feature dataset it resides in as versioned if edits are to be made to the feature classes.

• Problem:

  An error is encountered when building a terrain.

  Suggestion 1:

  Make sure all feature classes have valid spatial indexes.

  Suggestion 2:

  If a feature class already exists with an identical name to a private feature class a terrain wants to build (for example, DTM_14_DirtyArea), terrain building will fail.

• Problem:

  A terrain dataset cannot be plotted.

  Suggestion:

  Plotting many triangles can be a problem. Rasterize the terrain and plot that.

• Problem:

  Drawing of a terrain dataset in ArcMap is really slow. It only draws a handful of triangles at a time.

  Suggestion:

  Make sure the map is in the projection of the terrain dataset. It could be that on-the-fly projection is slowing it down.

• Problem:

  The build process seems to step slowly through the phase 2 (or empty tile) process. Usually, this process is much quicker.

  Suggestion:

  This indicates that an unusually large number of empty tiles exist in the terrain dataset. This may be valid or could be a result of an incorrect extent recorded for one of the inputs. For example, if the data extent of a feature class was reduced through some form of editing, its recorded extent is not accurate. In this state, the terrain thinks the extent is one thing, but the actual extent differs and results in many empty tiles. This is a data problem, and the extent of the feature class must be recalculated.

• Problem:

  When data has been appended to a terrain dataset, the build process on an existing terrain (update) fails.

  Suggestion:

  Examine the source of the appended data. Is the extent as expected? It could be the appended data has a mistake in it, which created a large x,y extent.

• Problem:

  The terrain build process consumes a lot of memory.

  Suggestion:

  Too large of a point spacing may have been used. Check the data and make sure the point spacing used is correct.

• Problem:

  Access to/Viewing of the overview terrain is slow.

  Suggestion:

  Upgrade the geodatabase to ArcGIS 10. Respond yes when asked if you want to optimize the overview when viewing the terrain.