Drone2Map allows you to create Digital Surface Models (DSM's). The value of Drone2Map is that the DSM's get automatically uploaded to your Portal or ArcGIS Online.
Unfortunately you can't load the DSM's directly into a new web scene as a surface layer.
Currently you have to add the DSM into ArcGIS PRO first and publish a web scene before you can then use the DSM as a source of elevation within the scene viewer. See: http://server.arcgis.com/en/portal/latest/use/get-started-scenes.htm
It would be more productive if you could publish your DSM to Portal or ArcGIS Online from Drone2Map and for that surface to be useable as an elevation source immediately within the scene viewer, without the need to take the DSM back into PRO first. The whole idea of Drone2Map is to get data from the drone to be useful within the rest of the ArcGIS platform as quickly as possible. Having to use two different parts of the ArcGIS Platform in order to make use of the elevation data captured from the drone within the scene viewer could be made more efficient.
It would seem that if the DSM is already uploaded to the portal by Drone2Map then then the scene viewer should be able to leverage that DSM as soon as its uploaded.
