Bug report: RhinoViewport.CameraDirection property oddly modified by 3dConnexion mouse navigation

I found out today, after debugging some issues with a component I’m working on with preview overrides / UI overlays, that the 3dConnexion mouse was the culprit to some issues I was having.

I noted while debugging in Visual Studio that the RhinoViewport.CameraDirection property changes drastically when you move the 3dConnexion versus when you rotate/pan/etc with the normal mouse. In my own instance, the vector for camera direction went from, with mouse engaged, something like {-9, -5, -16} to, with the 3d Connexion engaged , something like {-90,000, -47,000, -144,000}, while the view change was extremely minimal.

I also note that the other properties of the Viewport did not change to this extreme (camera position and target stayed reasonable). This leads me to believe that there is a bug at play here.

For myself, I’ve resolved this in our code by deriving camera direction as a unitized vector between the camera position and camera target, however I’m recommending that McNeal look into this.