View on GitHub Sample viewer app

Perform an exploratory viewshed analysis from a defined vantage point.

Use case

An exploratory viewshed analysis is a type of visual analysis you can perform at the current rendered resolution of a scene. The exploratory viewshed shows what can be seen from a given location. The output is an overlay with two different colors - one representing the visible areas (green) and the other representing the obstructed areas (red).

Note: This analysis is a form of “exploratory analysis”, which means the results are calculated on the current scale of the data, and the results are generated very quickly but not persisted. If persisted analysis performed at the full resolution of the data is required, consider using a ViewshedFunction to perform a viewshed calculation instead.

How to use the sample

Use the sliders to change the properties (heading, pitch, etc.), of the exploratory viewshed and see them updated in real time. To move the exploratory viewshed, double touch and drag your finger across the screen. Lift your finger to stop moving the exploratory viewshed.

How it works

  1. Create a ExploratoryLocationViewshed passing in the observer location, heading, pitch, horizontal/vertical angles, and min/max distances.
  2. Set the property values on the exploratory viewshed instance for location, direction, range, and visibility properties.

Relevant API

  • AnalysisOverlay
  • ArcGISSceneLayer
  • ArcGISTiledElevationSource
  • ExploratoryLocationViewshed

About the data

The scene shows a buildings layer in Brest, France hosted on ArcGIS Online.

Tags

3D, exploratory viewshed, frustum, scene, visibility analysis

Sample Code

ColorDialog.qml ColorDialog.qml ShowExploratoryViewshedFromPointInScene.cpp ShowExploratoryViewshedFromPointInScene.h ShowExploratoryViewshedFromPointInScene.qml ViewshedSlider.qml main.cpp
// [WriteFile Name=ViewshedLocation, Category=Analysis]
// [Legal]
// Copyright 2018 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
import QtQuick.Controls
import QtQuick.Layouts
Dialog {
id: colorDialog
property alias red: redSlider.value
property alias green: greenSlider.value
property alias blue: blueSlider.value
property alias alpha: alphaSlider.value
readonly property color color: Qt.rgba(red, green, blue, alpha);
title: qsTr("Pick a color")
standardButtons: Dialog.Ok | Dialog.Cancel
function setColor(c) {
red = c.r;
green = c.g;
blue = c.b;
alpha = c.a;
}
GridLayout {
columns: 2
Rectangle {
Layout.columnSpan: 2
Layout.fillWidth: true
height: redSlider.height
border {
color: "black"
width: 1
}
radius: 2
color: colorDialog.color
}
Label {
text: qsTr("Red")
}
Slider {
id: redSlider
}
Label {
text: qsTr("Green")
}
Slider {
id: greenSlider
}
Label {
text: qsTr("Blue")
}
Slider {
id: blueSlider
}
Label {
text: qsTr("Alpha")
}
Slider {
id: alphaSlider
}
}
}