I have many buildings in CityGML format. Currently cesium does not parse citygml. I tried Geojson and KML formats as in Cesium official tutorials using Sandcastle. In geojson buildings can be seen only 2d (as footprints) and in kml experience Cesium gives an error "Unsupported geometry type: model". I want to render both 3d geometries and semantic attributes in Cesium. I have approximately 2000 buildings. So, What is the best and easiest way to visualize buildings and their attributes in Cesium?