In an ArcGIS Pro scene, I am attempting to display a hillshade raster draped on a 20-m pixel, 7500X7500 cell DEM. The map meets my requirements except that when viewed at a scale of 200,000 above ground, there are empty patches in the hillshade, these go away at 75,000 feet above ground zoom or less, but I would like to produce maps at the smaller (200,000 ft) scale. I have offset the hillshade 100 m above the DEM to avoid any instances of the hillshade 'tunneling' below the DEM. There should be no horizontal offset between the hillshade and DEM as the hillshade is a direct derivative of the DEM. I am using ArcGIS Pro 2.2.4.
Thanks kindly for any help you might provide! See illustrations below.
White patches in 200, 000 ft above ground zoom view of hillshade draped on DEM.
White patches do disappear at 75,000 ft zoom level or less.