LineOfSightAnalysis

LineOfSightAnalysis computes the line of sight from a single observer position towards a set of targets. The results are visualized in a 3D SceneView.

To display the line of sight between two points, create a new instance of LineOfSightAnalysis, add it to SceneView.analyses, and set the observer and targets properties.

If the observer position or target position have z-values then these will be treated as absolute values, otherwise the points will be aligned to the ground.

Use the LineOfSightAnalysisView3D to retrieve analysis results.

// create line of sight analysis
const lineOfSightAnalysis = new LineOfSightAnalysis({
  observer: new LineOfSightAnalysisObserver({ position: new Point({ }) }),
  targets:[
    new LineOfSightAnalysisTarget({ position: new Point({ }) })
  ]
});

// add to the view
view.analyses.add(lineOfSightAnalysis);

// wait for the view to not be updating to ensure we get the latest results.
await reactiveUtils.whenOnce(() => !view.updating);

// retrieve the results from the analysis view.
const analysisView = await view.whenAnalysisView(lineOfSightAnalysis);
const results = analysisView.results;

The line of sight analysis can also be added to a LineOfSightLayer which can be persisted in a web scene:

// create line of sight layer containing the analysis
const lineOfSightLayer = new LineOfSightLayer({
  analysis: lineOfSightAnalysis
});

// add to the map
view.map.add(lineOfSightLayer);

To place the observer and targets interactively, use the LineOfSightAnalysisView3D.place() method.

const abortController = new AbortController();

try {
  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();

The analysis results are displayed as colored lines, where areas visible to the observer are shown green and occluded parts are marked in red. Also, the color of the target points indicates their visibility. When the line of sight cannot be calculated, it will be displayed with a gray color. This may happen if either the target or the observer is not in the view.

Use the Line Of Sight component to display a user interface for the line of sight analysis.