ArcObjects Library Reference (Geometry)  

esriGeometryDimension Constants

The topological dimension of a geometry.

Constant Value Description
esriGeometry0Dimension 1 A zero dimensional geometry (such as a point or multipoint).
esriGeometry1Dimension 2 A one dimensional geometry (such as a polyline).
esriGeometry2Dimension 4 A two dimensional geometry (such as a polygon).
esriGeometry25Dimension 5 A 2.5D geometry (such as a surface mesh).
esriGeometry3Dimension 6 A 3D geometry.
esriGeometryNoDimension -1 The dimension is unknown or unspecified.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Remarks

Describes the dimensionality of the geometry object. Each dimension corresponds to a direction of orthogonal movement. Therefore, Zero Dimensions describes a point with no extent beyond the point itself. One Dimension describes a line where the dimension of movement extends along the length of the line. Two Dimensions describes a surface where the movement can occur along two parametric orthogonal axes to create an Area. Three Dimensions describes a space with three parametric directions of movement (height, width, and depth). 2.5 Dimensions is a pseudo-dimensional construct that refers to a functional surface, represented by a planar Two Dimensional object with Z attributes. A No Dimensional object (not to be confused with a Zero Dimensional point) is an object for which dimensionality is not properly defined.

esriGeometry0Dimension   = Points and Multipoints
esriGeometry1Dimension = Segments, Paths, and Polylines
esriGeometry2Dimension = Envelopes, Rings, Polygons and Multipatches
esriGeometry25Dimension = ZAware esriGeometry2Dimension objects
esriGeometry3Dimension = New upcoming geometry type
esriGeometryNoDimension = GeometryBags

Dimension Example