I have designed an implementation of ArcObjects' IDistanceOP.EucDistanceFull. It takes its input as a feature class and converts it to a GeoDataset with which EucDistanceFull can work with. It works fine with feature classes in projected coordinate systems, but doesn't execute property on feature classes with unknown or geographic coordinate systems (It will output a blank or black raster).
What could be the issue here? I don't see anywhere in the library documentation that states that EucDistanceFull requires projected coordinate systems.