Viewshed on 3D Model

[MarekJamrozy]

I would like to use the interactive viewshed analysis tool, to evaluate the visibility of a windfarm and tought as a newbie, I had everything set up properly. I am using my own DEM as Elevation Surface, and the arcGIS Pro wind turbine 3D model for the positions (point features) of the turbines. 

https://imgur.com/a/P5ah62g

But in contrast to the pubilished scene of a viewshed analysis for an windturbine, my windturbine does not reflect the viewshed colors if visible or not, so is not part of the viewshed.
Is there a way to let the 3D Models of the wind turbines be taken into account? In the published scene the 3D Model of the turbine is described as a Format Mesh Symbol, which I am not familiar with