Adjusting horizon in VIZ from Revit model

[cliburn]

I have exported a model with a camera view from Revit into VIZ. The only thing wrong is that the horizon line is always in the middle of the rendered view using the same camera. Everything about the view is the same as it is in Revit, but Revit has this cool feature called "Slide" that I have used to show less ground and more sky without adjusting the height of the camera or target. Does anyone know how this colud be done in VIZ? I have had no luck with any other VIZ forums.

Thanks,
David