Blend a hillshade with a raster by specifying the elevation data. The resulting raster looks similar to the original raster, but with some terrain shading, giving it a textured look.
Use case
BlendRenderer
can be used to apply a color ramp to a hillshade to emphasize areas of high or low elevation. A BlendRenderer
can also be used to add a hillshade effect to aerial or satellite imagery, thereby making changes in elevation more visible.
How to use the sample
Tap on "Edit Renderer" in the toolbar to change the settings for the blend renderer. Choose and adjust the altitude, azimuth, slope type and color ramp type settings to update the image.
How it works
- Create a
Raster
object from a raster file. - Create a
RasterLayer
object from the raster. - Create a
Basemap
object from the raster layer and set it to the map. - Create another
Raster
object for elevation from a grayscale raster file. - Create a
BlendRenderer
object, specifying the elevation raster, color ramp, and other properties.- If you specify a non-null color ramp, use the elevation raster as the base raster in addition to the elevation raster parameter. That way, the color ramp is used instead of the satellite imagery.
- Set the blend renderer to the raster layer.
Relevant API
- BlendRenderer
- ColorRamp
- Raster
- RasterLayer
Offline Data
Read more about how to set up the sample's offline data here.
Link | Local Location |
---|---|
Shasta.tif raster | <userhome> /ArcGIS/Runtime/Data/raster/Shasta.tif |
Shasta_Elevation.tif raster | <userhome> /ArcGIS/Runtime/Data/raster/Shasta_Elevation.tif |
Tags
color ramp, elevation, hillshade, image, raster, raster layer, visualization
Sample Code
// [WriteFile Name=BlendRasterLayer, Category=Layers]
// [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]
#ifdef PCH_BUILD
#include "pch.hpp"
#endif // PCH_BUILD
#include "BlendRasterLayer.h"
#include "Map.h"
#include "MapQuickView.h"
#include "Raster.h"
#include "RasterLayer.h"
#include "BlendRenderer.h"
#include <QDir>
#include <QtCore/qglobal.h>
#ifdef Q_OS_IOS
#include <QStandardPaths>
#endif // Q_OS_IOS
using namespace Esri::ArcGISRuntime;
// helper method to get cross platform data path
namespace
{
QString defaultDataPath()
{
QString dataPath;
#ifdef Q_OS_ANDROID
dataPath = "/sdcard";
#elif defined Q_OS_IOS
dataPath = QStandardPaths::writableLocation(QStandardPaths::DocumentsLocation);
#else
dataPath = QDir::homePath();
#endif
return dataPath;
}
} // namespace
BlendRasterLayer::BlendRasterLayer(QQuickItem* parent /* = nullptr */):
QQuickItem(parent),
m_dataPath(defaultDataPath() + "/ArcGIS/Runtime/Data/raster")
{
}
BlendRasterLayer::~BlendRasterLayer() = default;
void BlendRasterLayer::init()
{
// Register the map view for QML
qmlRegisterType<MapQuickView>("Esri.Samples", 1, 0, "MapView");
qmlRegisterType<BlendRasterLayer>("Esri.Samples", 1, 0, "BlendRasterLayerSample");
}
void BlendRasterLayer::componentComplete()
{
QQuickItem::componentComplete();
// find QML MapView component
m_mapView = findChild<MapQuickView*>("mapView");
m_mapView->setWrapAroundMode(WrapAroundMode::Disabled);
// Create the raster and raster layer
Raster* raster = new Raster(m_dataPath + "/Shasta.tif", this);
m_rasterLayer = new RasterLayer(raster, this);
m_elevationRaster = new Raster(m_dataPath + "/Shasta_Elevation.tif", this);
m_rasterLayerColorRamp = new RasterLayer(m_elevationRaster, this);
// Add the raster to the map
m_basemap = new Basemap(m_rasterLayer, this);
m_basemapColorRamp = new Basemap(m_rasterLayerColorRamp, this);
m_map = new Map(m_basemap, this);
m_mapView->setMap(m_map);
}
void BlendRasterLayer::applyRenderSettings(double altitude, double azimuth, int slopeTypeVal, int colorRampTypeVal)
{
PresetColorRampType colorRampType = static_cast<PresetColorRampType>(colorRampTypeVal);
RasterLayer* rasterLyr = rasterLayer(colorRampType != PresetColorRampType::None);
if (!rasterLyr)
return;
QList<double> outputMinValues{9};
QList<double> outputMaxValues{255};
QList<double> sourceMinValues;
QList<double> sourceMaxValues;
QList<double> noDataValues;
QList<double> gammas;
double zFactor = 1.;
double pixelSizeFactor = 1.;
double pixelSizePower = 1.;
int outputBitDepth = 8;
ColorRamp* colorRamp = ColorRamp::create(colorRampType, 800, this);
SlopeType slopeType = static_cast<SlopeType>(slopeTypeVal);
BlendRenderer* renderer = new BlendRenderer(m_elevationRaster,
outputMinValues,
outputMaxValues,
sourceMinValues,
sourceMaxValues,
noDataValues,
gammas,
colorRamp,
altitude,
azimuth,
zFactor,
slopeType,
pixelSizeFactor,
pixelSizePower,
outputBitDepth,
this);
rasterLyr->setRenderer(renderer);
}
RasterLayer* BlendRasterLayer::rasterLayer(bool useColorRamp)
{
m_map->setBasemap(useColorRamp ? m_basemapColorRamp : m_basemap);
return useColorRamp ? m_rasterLayerColorRamp : m_rasterLayer;
}