I am hoping that someone has done this before me and can point me in the right direction for how I might create a raster mask. I am working on a project in ArcObjects VBA that has users working with rasters. Currently, I have the user creating an envelope and clipping a selected raster by that envelope. Hillshade calculations are then performed on the clipped raster. The entire procedure takes quite a bit of time. In order to speed up the process, I would like to create a raster mask instead of clipping the raster in order to specify which section the hillshade calculation should be performed on. Is it possible to create a mask using the envelope? Or even the points the user creates in order to make the envelope? The Raster interfaces have me so confused; I am not sure what to do.
Any help would be appreciated.