Update the orientation of a graphic using expressions based on its attributes.
Use case
Instead of reading the attribute and changing the rotation on the symbol for a single graphic (a manual CPU operation), you can bind the rotation to an expression that applies to the whole overlay (an automatic GPU operation). This usually results in a noticeable performance boost (smooth rotations).
How to use the sample
Adjust the heading and pitch sliders to rotate the cone.
How it works
- Create a new graphics overlay.
- Create a simple renderer and set its scene properties.
- Set the heading expression to
[HEADING]
. - Apply the renderer to the graphics overlay.
- Create a graphic and add it to the overlay.
- To update the graphic's rotation, update the
HEADING
orPITCH
property in the graphic's attributes.
Relevant API
- Graphic::attributes
- GraphicsOverlay
- SceneProperties
- SceneProperties::headingExpression
- SceneProperties::pitchExpression
- SimpleRenderer
- SimpleRenderer::sceneProperties
Tags
3D, expression, graphics, heading, pitch, rotation, scene, symbology
Sample Code
// [WriteFile Name=ScenePropertiesExpressions, Category=Scenes]
// [Legal]
// Copyright 2019 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]
#ifdef PCH_BUILD
#include "pch.hpp"
#endif // PCH_BUILD
#include "ScenePropertiesExpressions.h"
#include "ArcGISTiledElevationSource.h"
#include "Basemap.h"
#include "Scene.h"
#include "SceneQuickView.h"
#include "SimpleMarkerSceneSymbol.h"
#include "SimpleRenderer.h"
using namespace Esri::ArcGISRuntime;
namespace
{
const QString HEADING("HEADING");
const QString PITCH("PITCH");
}
ScenePropertiesExpressions::ScenePropertiesExpressions(QObject* parent /* = nullptr */):
QObject(parent),
m_scene(new Scene(BasemapStyle::ArcGISImageryStandard, this))
{
// create a new elevation source from Terrain3D REST service
ArcGISTiledElevationSource* elevationSource = new ArcGISTiledElevationSource(
QUrl("https://elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer"), this);
// add the elevation source to the scene to display elevation
m_scene->baseSurface()->elevationSources()->append(elevationSource);
m_graphicsOverlay = new GraphicsOverlay(this);
m_graphicsOverlay->setSceneProperties(LayerSceneProperties(SurfacePlacement::Relative));
// Create a SimpleRenderer and set expressions on its scene properties.
// Then, set the renderer to the graphics overlay with GraphicsOverlay.setRenderer(renderer).
SimpleRenderer* renderer3D = new SimpleRenderer(this);
RendererSceneProperties renderProperties = renderer3D->sceneProperties();
renderProperties.setHeadingExpression(QString("[%1]").arg(HEADING));
renderProperties.setPitchExpression(QString("[%1]").arg(PITCH));
renderer3D->setSceneProperties(renderProperties);
m_graphicsOverlay->setRenderer(renderer3D);
}
ScenePropertiesExpressions::~ScenePropertiesExpressions() = default;
void ScenePropertiesExpressions::init()
{
// Register classes for QML
qmlRegisterType<SceneQuickView>("Esri.Samples", 1, 0, "SceneView");
qmlRegisterType<ScenePropertiesExpressions>("Esri.Samples", 1, 0, "ScenePropertiesExpressionsSample");
}
SceneQuickView* ScenePropertiesExpressions::sceneView() const
{
return m_sceneView;
}
// Set the view (created in QML)
void ScenePropertiesExpressions::setSceneView(SceneQuickView* sceneView)
{
if (!sceneView || sceneView == m_sceneView)
{
return;
}
m_sceneView = sceneView;
m_sceneView->setArcGISScene(m_scene);
// create a camera
const double latitude = 32.09;
const double longitude = -118.71;
const double altitude = 100000.0;
const double heading = 0.0;
const double pitch = 45.0;
const double roll = 0.0;
const int coneDimension = 10000;
Camera camera(latitude - 1.0, // place the camera arbitrarily south of the cone
longitude,
altitude * 2, // place the camera arbitrarily higher than the cone
heading,
pitch,
roll);
// set the viewpoint
m_sceneView->setViewpointCameraAndWait(camera);
// add the graphics overlay to the scene view
m_sceneView->graphicsOverlays()->append(m_graphicsOverlay);
// create a scene symbol based on the current type
SimpleMarkerSceneSymbol* smss = new SimpleMarkerSceneSymbol(SimpleMarkerSceneSymbolStyle::Cone, QColor("red"), 200, 200, 200, SceneSymbolAnchorPosition::Center, this);
smss->setWidth(coneDimension);
smss->setDepth(coneDimension);
smss->setHeight(coneDimension * 2);
// create a graphic using the symbol above and a point location
m_graphic = new Graphic(Point(longitude, latitude, altitude, m_sceneView->spatialReference()), smss, this);
m_graphic->attributes()->insertAttribute(HEADING, 0);
m_graphic->attributes()->insertAttribute(PITCH, 0);
// add the graphic to the graphics overlay
m_graphicsOverlay->graphics()->append(m_graphic);
emit sceneViewChanged();
}
void ScenePropertiesExpressions::setPitch(double pitchInDegrees)
{
m_graphic->attributes()->replaceAttribute(PITCH, pitchInDegrees);
emit pitchChanged();
}
double ScenePropertiesExpressions::pitch() const
{
return m_graphic->attributes()->attributeValue(PITCH).toDouble();
}
void ScenePropertiesExpressions::setHeading(double headingInDegrees)
{
m_graphic->attributes()->replaceAttribute(HEADING, headingInDegrees);
emit headingChanged();
}
double ScenePropertiesExpressions::heading() const
{
return m_graphic->attributes()->attributeValue(HEADING).toDouble();
}