ViewshedAnalysis

ViewshedAnalysis enables the creation and display of viewshed and view dome type of visibility analysis in a 3D SceneView.

The analysis can contain multiple viewsheds. These can be created interactively or programmatically, and the analysis can be added directly to SceneView.analyses or to the ViewshedLayer.source in a SceneView.map.

 const viewshed = new Viewshed({
   observer: new Point({ }),
   farDistance: 900,
   heading: 64,
   tilt: 84,
   horizontalFieldOfView: 85,
   verticalFieldOfView: 52
 });
 const viewshedAnalysis = new ViewshedAnalysis({
   viewsheds: [viewshed],
 });

 // add the analysis to the view
 view.analyses.add(viewshedAnalysis);

To add a viewshed interactively, use the ViewshedAnalysisView3D.place() method.

const abortController = new AbortController();

try {
  // get a view for the analysis
  const analysisView = await view.whenAnalysisView(viewshedAnalysis);

  // start placing a new viewshed interactively
  await analysisView.place({ signal: abortController.signal });
} catch (error) {
  if (error.name === "AbortError") {
    console.log("Placement operation was cancelled.");
  }
}

// cancel the placement operation at some later point
abortController.abort();

To edit existing viewsheds interactively, set the ViewshedAnalysisView3D.interactive property true and select a viewshed by hovering and clicking on their field-of-view manipulators.

// allow existing viewsheds in the analysis to be selected and edited
analysisView.interactive = true;

A ViewshedAnalysis can be persisted in a WebScene as part of a ViewshedLayer.