Hello
Is there always only one Unwrap feature?
Is there always only one WorkSurface?
Is the unwrapped surface always a circle?
If so, you can use iLogic below to get the radius as parameter "radius". Add this rule to the event trigger "on model geometry change". Every time you change the model, the parameter will be updated.
This rule is for this one specific situation your screenshot shows.
Dim oPartDoc As PartDocument = ThisDoc.Document
Dim oUOM As UnitsOfMeasure = oPartDoc.UnitsOfMeasure
Dim oCompdef As PartComponentDefinition = oPartDoc.ComponentDefinition
Dim oWorkSurface As WorkSurface = oCompdef.WorkSurfaces.Item(1)
Dim oSurfaceBody As SurfaceBody = oWorkSurface.SurfaceBodies.Item(1)
Dim oEdge As Edge = oSurfaceBody.Edges.Item(1)
Dim oCircle As Circle = oEdge.Geometry
Dim dRadius As Double = oUOM.ConvertUnits(oCircle.Radius ,"cm",oUOM.LengthUnits)
Dim oParam As UserParameter
Try
oCompdef.Parameters.UserParameters.Item("radius").Expression=dRadius & oUOM.LengthUnits
Catch
oCompdef.Parameters.UserParameters.AddByExpression("radius", dRadius, oUOM.LengthUnits )
End Try
R. Krieg
RKW Solutions
www.rkw-solutions.com