EllipseOperator.Margin Property
Gets or sets a margin added to the view area when requesting data from the input operator.
Syntax
public System.Double Margin { get; set; }Property Value
Default: 100000.0
A margin added to the view area when requesting data from the input operator, specified in meters.
Remarks
This property specifies a margin that the operator adds to the view area when requesting data from its input. The margin should be larger than any possible radius, but note that their units may differ.
Why it is needed: A view presents the features visible inside its view area, and will normally ask its input for features inside the area. But an EllipseOperator can create a feature that is (partially) visible in the area from a point that is outside the area, if the radius is long enough. So the operator should extend the area with the longest possible radius, when it requests data from its input. The trouble is that the operator does not know the longest possible radius in advance. The radius may be an IndirectAttributeVariable<System.Double>, and there just might be a point at the antipodes with a range of 20000000 meters. Since it would be inefficient to request data from the entire world at every update, the operator assumes that the margin property is large enough.
Platforms
Windows, Linux, Android