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DrawContext.IsTransparentPass

Method
Description:
Determines whether the current rendering pass is for transparent objects.
Remarks:

Opaque and transparent geometry should be submitted for rendering separately. See UseInTransparentPass(View).

Syntax
public static bool IsTransparentPass()
Exceptions
Exception Condition
InvalidOperationException This DrawContext is not available because Revit is not currently rendering. In general, this DrawContext must be used in the scope of the RenderScene() callback of IDirectContext3DServer.