tweaks for ospray lights
positional light soft shadow parameter name was wrong. apply kludges to the too bright ambient and too dim positional lights be sure to override a new vtkLight subclass that we are planning to add to ParaView.
positional light soft shadow parameter name was wrong. apply kludges to the too bright ambient and too dim positional lights be sure to override a new vtkLight subclass that we are planning to add to ParaView.