Multidirectional Hillshade with custom main azimuth?
Hello, I'm using a Raster Function in ArcGIS Pro 2.9 to generate a Multidirectional Hillshade layer based on a DEM I created from a LiDAR point cloud. It works, but there's no way that I can see to change the "main" illumination direction/azimuth. (the Multidirectional Hillshade combines several illumination directions but seems to have a strong "main/primary" illumination from the northwest). The Traditional Hillshade Raster Function and the Hillshade geoprocessing tool let you set the azimuth (and altitude) to whatever you like, but they don't have a "Multidirectional" option.
The reason I need this is that the map I'm making is rotated (north is not up), so the hillshade doesn't read properly unless I can change the main illumination azimuth to be from (e.g.) the upper left of my rotated map. See attached images (they're rough, I haven't done any smoothing yet). In the rotated one, the valley (Purgatory Chasm) appears "inverted" because the main illumination is coming from the right.
Image 1: unrotated (north is up, main illumination is coming from the upper left, looks fine):
Image 2: rotated -145° (north is to the lower right, illumination is coming from the right, doesn't look the way it should):
I've searched the forums as best I can, to no avail. Apologies if I missed something obvious. So, a few questions:
- Is there a way to get the Multidirectional Hillshade Raster Function to use a different "main/primary" azimuth?
- Are there any other tools (besides that Raster Function) that can generate a Multidirectional Hillshade? (i.e. a geoprocessing tool, script, etc.). If so, do they let you change the main illumination direction?
Thanks!
