When performing a visibility calculation between an observer domain object and an observed domain object, Lucy calculates:

  • An ILcdPoint representing the location of the observer.

  • The mode to interpret the Z-value of the ILcdPoint. For example, a Z-value of 100.0 might mean 100 meters above the terrain or 100 meters above the ellipsoid.

  • An ILcdShape representing the shape of the observed domain object.

  • The mode to interpret the Z-values of the ILcdShape.

This information is given by providers created in the TLcyShapeVisibilityAddOn, through the createPointObserverShapeProvider and createObserveeShapeProvider methods. To return a custom provider with custom logic, you can override those methods.