Viewshed Tool

icon coneViewshed The viewshed tool allows the user to visualize the visibility of a specific location in 3D space. Objects within the observer’s field of vision are illuminated and objects that cannot be seen are shaded.

Two different modes are available:

The cone viewshed mode is directional, this allows the viewing direction to be determined in addition to the viewer’s viewpoint and distance, the analysis area is limited by the field of view.
In 360° viewshed mode, an all-round analysis is performed. Only the viewpoint and a distance that determines the analysis area are selected.

Clicking the corresponding icon starts the analysis tool and opens the corresponding settings window.

Cone Viewshed

To initialize the cone viewshed analysis, first select the height mode. The viewpoint must then be determined with a first click, a second click determines the analysis distance and viewing direction. After this input, the selected parameters are displayed in the settings window for further adjustments and interactions:

Option	Description
Viewpoint	Jump to viewpoint: The map view jumps to the position of the viewpoint and displays the analysis from the viewer’s perspective. / Move viewpoint: Activates the inputs for to move the set viewpoint relative in X, Y or Z direction and the cursor for interactive moving of the object in the map.
Position	Shows the coordinates of the position of the set viewpoint. These can be edited via manual input.
Height mode	Relative to ground: Position specification in Z direction refers to the height above the terrain. The default setting is 1.80 m (human observer). In height mode relative to ground, the viewpoint can only be positioned at the selected relative distance to the terrain; objects such as buildings are not taken into account when positioning. Absolute: Position specification in the Z direction refers to the absolute height. In absolute height mode, the viewpoint can be positioned anywhere in 3D space. This also makes it possible to position the viewpoint on an object.
Show viewpoint	Display the position of the lighting object and the cone geometry in the 3D scene.
Distance [m]	Changes the analysis distance (viewing distance) .
Field of view	Adjust the field of view, for example to simulate a pair of eyes or a camera lens with different focal lengths.
Orientation	Change the main analysis direction in the horizontal plane, the value can be set from 0 - 360°.
Tilt	Change the tilt of the main analysis direction in the vertical plane, the value can be set from -90° - 90°.

Option

Description

Viewpoint

icon human male Jump to viewpoint: The map view jumps to the position of the viewpoint and displays the analysis from the viewer’s perspective.

icon editVertices / icon axisArrow Move viewpoint: Activates the inputs for to move the set viewpoint relative in X, Y or Z direction and the cursor for interactive moving of the object in the map.

Position

Shows the coordinates of the position of the set viewpoint. These can be edited via manual input.

Height mode

Relative to ground: Position specification in Z direction refers to the height above the terrain. The default setting is 1.80 m (human observer). In height mode relative to ground, the viewpoint can only be positioned at the selected relative distance to the terrain; objects such as buildings are not taken into account when positioning.

Absolute: Position specification in the Z direction refers to the absolute height. In absolute height mode, the viewpoint can be positioned anywhere in 3D space. This also makes it possible to position the viewpoint on an object.

Show viewpoint

Display the position of the lighting object and the cone geometry in the 3D scene.

Distance [m]

Changes the analysis distance (viewing distance) .

Field of view

Adjust the field of view, for example to simulate a pair of eyes or a camera lens with different focal lengths.

Orientation

Change the main analysis direction in the horizontal plane, the value can be set from 0 - 360°.

Tilt

Change the tilt of the main analysis direction in the vertical plane, the value can be set from -90° - 90°.

360°-Viewshed

To initialize the 360° viewshed analysis, first select the height mode. The viewpoint must then be determined with a first click, and a second click determines the analysis distance. After this input, the selected parameters are displayed in the settings window for further adjustments and interactions:

Option	Description
Viewpoint	/ Move viewpoint: Activates the inputs for to move the set viewpoint relative in X, Y or Z direction and the cursor for interactive moving of the object in the map.
Position	Shows the coordinates of the position of the set viewpoint. These can be edited via manual input.
Height mode	Relative to ground: Position specification in Z direction refers to the height above the terrain. The default setting is 1.80 m (human observer). In height mode relative to ground, the viewpoint can only be positioned at the selected relative distance to the terrain; objects such as buildings are not taken into account when positioning. Absolute: Position specification in the Z direction refers to the absolute height. In absolute height mode, the viewpoint can be positioned anywhere in 3D space. This also makes it possible to position the viewpoint on an object.
Show viewpoint	Display the position of the lighting object and the cone geometry in the 3D scene.
Distance [m]	Changes the analysis distance (viewing distance). The maximum is set to 2000 Meters.

Option

Description

Viewpoint

Position

Shows the coordinates of the position of the set viewpoint. These can be edited via manual input.

Height mode

Show viewpoint

Display the position of the lighting object and the cone geometry in the 3D scene.

Distance [m]

Changes the analysis distance (viewing distance). The maximum is set to 2000 Meters.

When the viewshed tool is opened, a temporary field of view analysis is created in which the settings made are applied. If the settings are to be discarded, you can click on the NEW button to start from the original state with new settings.

icon workspace plus adds the analysis result to My Workspace in order to display or edit it again during the active session, to create and compare several analysis or to export them from there. Further information on this can be found at: Interaction with My Workspace.

Interaction with My Workspace

Each viewshed added to My Workspace is listed there in the viewsheds section.

Using the icon overflow menu at the end of each entry, it is possible to

rename the element.
jump to the extent of the field of view.
edit the properties of the analysis.
remove the analysis result from My Workspace.

Export viewshed

Click on one or more elements in My Workspace to select them. The selected elements can then be exported as GeoJSON via the icon overflow menu of the viewsheds section. This allows the analysis geometry to be saved permanently beyond the current session or to be passed on to third parties.

This step only exports the analysis geometry and the set parameters, not the analysis results. If the viewshed is imported again into the same scene, the analysis results are displayed in the VC Map app. The JPG or PDF generator of the sharing tool can be used to document the results.

Import viewshed

Exported viewsheds can be imported again at any time using the saved GeoJSON file, e.g. to continue working with this element when visiting the VC Map App again. To do this, open My Workspace. The import function is available in the icon overflow menu of the viewsheds section. After selecting a valid GeoJSON file that contains an analysis object, the entry is added to the section again. The viewshed is now available for viewing or further editing.