I have multiple polygons (destinations) and an elevation raster. For each raster cell in my study area, I need to calculate the distance to the nearest destination polygon. If I use the 'as crow flies' distances, that's easy (I can convert my polygons to raster, and then use the Raster\Analysis\Proximity in QGIS or raster - euclidean distance in ArcGIS).
In my application I need to get a 3D distance on the terrain surface. So, an "as crow flies" distance of 10 km would be bigger if there is a big hill or deep valley between them.
Is there any ArcGIS function similar to the "raster proximity" or "raster euclidean distance" that takes into account elevation change?
I'm looking for something like least cost path distance, but not just for two points but for every grid cell.