The WebScene I shared in the CAD to GIS Integration Webinar was built from importing CAD layers to GIS features. The GIS features were imported into CityEngine. Once the features were styled and symbology was finalized I published the WebScene to ArcGIS Online. The web scene was published by Esri and the workflow is very well documented in our help system for ArcGIS Pro and CityEngine. Here is a link to my WebScene which is an interactive web application featuring 3D features.