The Revit API discussion forum thread on drawing or rendering over the active view brought to my attention that an important new SDK sample created to demonstrate the use of the Revit 2018 functionality
DirectContext3D for display of externally managed 3D graphics in Revit is missing in the SDK.
I added it right here, in DuplicateGraphics.zip, and also provide an overview of the new SDK samples
– Structural Analysis CodeCheckingConcreteExample and CalculationPointsSelector
– REX SDK DRevitFreezeDrawing...