Scale PointSymbol3D based on zoom level

[TimoMartosatiman]

Hi! 

I got a question about scaling the PointSymbol3D objects. I want my 3D objects to scale when zooming in and out. I've seen several tutorials where the 3d objects get scaled based on the FeatureLayers. For my own 3D objects, I'm using the GraphicLayers instead of the FeatureLayers. Can anyone explain me how I can achieve the same with a GraphicLayer? 

Thanks in advance,

Timo