ArcObjects Library Reference (Editor)  

esriZCaptureType Constants

Method used by the editor to capture Z-values.

Constant Value Description
esriCaptureCurrentZ 0 Use Current Z value.
esriCaptureInterpolateZ 1 Interpolate Z value.
esriCaptureSurfaceZ 2 Derive Z value from surface.

Product Availability

Available with ArcGIS Desktop.

Remarks

esriCaptureCurrentZ new features are assigned a z-value based on IEditSketch2_CurrentZ

esriCaptureInterpolateZ will initially assign NaN to the z value of the new vertex when working with the edit sketch until the sketch is finished. Just before the sketch is completed these NaN values are resolved to a definite value.  At least one vertex in the sketch must have a simple z-value (non NaN) defined to successfully assign z-values using this method. The editor commands that do not interact with the edit sketch will immediatly resolve the z-value.

esriCaptureSurfaceZ requires that a surface is defined via IEditProperties4_Surface.  Each new vertex is assigned the z-value taken from the defined surface.