This is the .glb image I get when I try to use the clip feature and then proceed with the imagery & terrain option. My doubt is I would like to get a more realistic 3d terrain which I would like to download and then display offline. Is this blank issue due to my free plan will upgrading to another plan help me download a more realistic terrain? Image 2 is attached for reference notice how despite selecting Cesium World Terrain , it is just a blank blue globe
It looks like this is (nearly) a duplicate of Cesium Clip Terrain is Blank , but with additional information. It may be best to post further answers only on the other thread (to avoid duplicates)