Interface ILcdViewshed

All Known Implementing Classes:
ALcdCompositeViewshed, TLcdBoundedCompositeViewshed, TLcdCompositeViewshed, TLcdConeOfSilenceViewshed

public interface ILcdViewshed

The base interface for all viewsheds.

A viewshed is a representation of visibility of a 3D scene. A viewshed is defined in a specific reference and can describe the visibility of all points within this reference. Viewsheds are generally created for a positional viewpoint, or a viewing direction. (See ALcdViewshedObserver)

Figure 1: ILcdViewshed defines an interface to determine whether a point lies inside a visible volume. In this figure the gray regions are invisible to the observer.
The viewshed concept

Viewsheds represent visibility as a double:

  • Visibility 0 means the point is not visible.
  • Visibility 1 means the point is fully visible
  • Visibility between 0 and 1 means the point is partially visible. This can be either because:

Generating viewsheds should be done by either using the specific methods of the concrete implementations, or by using a matching ILcdViewshedFactory.

Visualizing viewsheds must be done by sampling the volume they represent, and converting the values to colors. One way of doing this is by using the TLcdViewshedMultilevelRaster class as a wrapper.

  • Method Summary

    Modifier and Type
    Returns the reference in which this viewshed is defined.
    Returns the visibility of a given point.
  • Method Details

    • getVisibility

      double getVisibility(ILcdPoint aPoint)
      Returns the visibility of a given point.
      aPoint - The point to check visibility of. The point must be given in the reference in which the viewshed is defined.
      A double indicating the visibility of the point. This value will be bound between 0 and 1. 0 represents non-visible. 1 represents fully visible. Anything in between 0 and 1 is partially visible, depending on specific cases.
    • getReference

      ILcdGeoReference getReference()
      Returns the reference in which this viewshed is defined.
      The reference in which viewshed is defined