Defining z and m domains

If you want to store z or m values with a feature class, when you create the feature class, you must specify that it will contain z or m values. You can also set spatial domains for these values. As with x,y domains, the geodatabase stores z and m values as integers between 0 and 2.14 billion.

Geodatabases can store z and m values in addition to x,y coordinate values.

If you are importing a coverage with m values (a route feature class) or a shapefile with z coordinates (a 3D shapefile), then the minimum and maximum m or z values default to the values in the source data. If you need to, you can change both the value range and the precision value.

If you do not import z or m domains, ArcCatalog will provide placeholder values which you will probably want to modify. For example, the placeholder minimum z and m domain values will not be a negative number. If you were creating a z domain that needed to include negatives, such as elevations below sea level, you would have to modify the z domain values.

The same placeholder values are provided for both z and m domains.

To modify the z or m domain, enter the lowest value you will need for your data and a precision value to support its accuracy.

While feature classes within a feature dataset must share the same x, y, and z domains, they can have different m domains.