how to display 3D bulidings with texture in Cesium?

I'm working on 3D web-GIS of an urban area. 3D buildings (with texture) were created in Arcgis and I'm looking for the best solution to display this 3D model on the web. I tried Cesium but I couldn't convert the KML file to CZML. What should I do to convert KML to CZML? Is there any other solution to display 3D buildins on the Web