This sample demonstrates how to perform a line of sight analysis between two points in a SceneView.
Use case
A line of sight analysis can be used to assess whether a view is obstructed between an observer and a target. Obstructing features could either be natural, like topography, or man-made, like buildings. Consider an events planning company wanting to commemorate a national event by lighting sequential beacons across hill summits or roof tops. To guarantee a successful event, ensuring an unobstructed line of sight between neighboring beacons would allow each beacon to be activated as intended.
How to use the sample
The sample loads with a preset observer and target location, linked by a colored line. A red segment on the line means the view between observer and target is obstructed, whereas green means the view is unobstructed.
Click to turn on the mouse move event listener, then move the mouse to update the target location in real time. Click again to lock the target location.
How it works
- Create an
AnalysisOverlay
and add it to the scene view. - Create a
LocationLineOfSight
with initial observer and target locations and add it to the analysis overlay. - Capture mouse movement with the
mousePositionChanged
signal. Turn the screen point into a scene point withsceneView.screenToLocation(screenPoint)
. - Update the target location with
lineOfSight.setTargetLocation(scenePoint)
.
Relevant API
- AnalysisOverlay
- ArcGISTiledElevationSource
- LocationLineOfSight
- SceneView
- Surface
Tags
3D, line of sight, visibility, visibility analysis
Sample Code
// [WriteFile Name=LineOfSightLocation, Category=Analysis]
// [Legal]
// Copyright 2017 Esri.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// [Legal]
import QtQuick 2.6
import QtQuick.Controls 2.2
import Esri.ArcGISExtras 1.1
import Esri.ArcGISRuntime 100.15
Rectangle {
clip: true
width: 800
height: 600
property bool calculating: false
SceneView {
id: sceneView
anchors.fill: parent
focus: true
Component.onCompleted: {
// Set the focus on SceneView to initially enable keyboard navigation
forceActiveFocus();
}
Scene {
id: scene
Basemap {
initStyle: Enums.BasemapStyleArcGISTopographic
}
Surface {
ArcGISTiledElevationSource {
url: "https://elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer"
}
}
onLoadStatusChanged: {
if (loadStatus === Enums.LoadStatusLoaded) {
setInitialViewpoint();
}
}
}
// Add an Analysis Overlay
AnalysisOverlay {
id: analysisOverlay
// Declare a LineOfSight and set initial observer and target locations
LocationLineOfSight {
id: locationLineOfSight
visible: true
observerLocation: Point {
x: -73.06958032962375
y: -49.253112971555446
z: 2000
spatialReference: Factory.SpatialReference.createWgs84()
}
targetLocation: Point {
x: -73.079266999709162
y: -49.300457676730559
z: 1312
spatialReference: Factory.SpatialReference.createWgs84()
}
// Configure the LoS color and width
Component.onCompleted: {
LineOfSight.setVisibleColor("cyan");
LineOfSight.setObstructedColor("magenta");
LineOfSight.setLineWidth(2);
}
}
}
// Update the target location as you tap the map
onMouseClicked: locationLineOfSight.targetLocation = sceneView.screenToBaseSurface(mouse.x, mouse.y);
onMousePressedAndHeld: calculating = true;
onMouseReleased: calculating = false;
onMousePositionChanged: {
if (!calculating)
return;
locationLineOfSight.targetLocation = sceneView.screenToBaseSurface(mouse.x, mouse.y);
}
}
function setInitialViewpoint() {
// Set a viewpoint
const point = ArcGISRuntimeEnvironment.createObject("Point", {
x: -73.0815,
y: -49.3272,
z: 4059,
spatialReference: Factory.SpatialReference.createWgs84()
});
const camera = ArcGISRuntimeEnvironment.createObject("Camera", {
location: point,
heading: 11,
pitch: 62,
roll: 0
});
sceneView.setViewpointCamera(camera);
}
}