I have loaded a shp file and some DTED data and into ArcMap. I created a custom BaseTool in C# that finds the layers that intersect the point clicked. When I click on a point that intersects the shp file layer, I am able to cast that to IRowIdentifyObject and extract the Fields and Values from the Row. But when I try to get the elevation data from the DTED layer I have no luck. It comes into C# as a COM Object and I need to know the specific interfaces it supports so I can cast it and access the elevation data. I also need to get the slope and upslope (azimuth) values.
I searched the ArcObjects SDK for elevation, but could not find an interface that the DTED layer supports. I tried IGlobeLayerProperties, esriGlobeDataType, ILayerExtensions, IGlobeDisplay, IFeatureLayer, ISurface, IFeature, IARGlobe, ITinSurfaceElement, IGlobeDisplayLayers and every interface in ESRI.ArcGIS.Carto (created code to generate a class that tested each interface).
I also tried using the ZMax and Zmin on the IGeometry (casted to an Envelope).