About Analysis in 3D
The ArcGIS 3D Analyst extension provides analysis capabilities for three-dimensional (3D) data. Both surfaces and feature data can be modeled in 3D allowing you to more realistically capture and understand phenomenon in the real world.
Many tasks can be performed using geoprocessing tools. It will generally be easier and more efficient to use an existing geoprocessing tool than trying to recreate that same functionality with ArcObjects.
See Also:
Using 3D Analyst geoprocessing toolsCreating a TIN
How to interpolate spot heights and profile lines on a TIN
How to open a terrain dataset
How to perform surface analysis on a terrain dataset
How to access a difference surface when intersecting TINs and terrains