Mesh layer is now supported for the 1D, 2D and 3D data frames. It also comes with integration to the temporal controller in QGIS 3.14.

The releases of QGIS 3.14, MDAL 0.6.1 and Crayfish 3.4.4 are planned for this Friday We are delighted to have made improvements for the upcoming release:

• full integration with the new temporal controller
• 1D meshes support (e.g. to support urban drainage system models)
• New rendering and styling options for mesh layers
• improving greatly rendering speed for large datasets
• various other enhancements and bug-fixes

If you are eager to try the latest features, you can always install QGIS nightlies/master.

Special thanks to all contributors and the sponsors of these features

• Deltares
• BMT
• Artelia Group

Do you want to use QGIS Mesh Layers in your projects? Read more…

Native QGIS Temporal Controller

The long awaited native temporal support in QGIS is finally materialised. We managed to port all QGIS Mesh Layer code to the new infrastructure and remove the custom time slider in the Mesh Layer properties/styling dialog. The native temporal support will greatly benefit users in the long run. We can now share the code components for time handing with raster, vector and WMS-T and other temporal data types. Also user can load multiple temporal layers and change time-domain for all of them at the same time.

Unfortunately, the new temporal framework changed the API, so if you use QgsMeshLayer in your plugins, consult the QGIS documentation for required changes.

New MDAL logo and docs

We have started writing the proper documentation for all supported formats and also reference documentation for developers. We welcome all contributions to improve the documentations. Just go to https://www.mdal.xyz and click “Edit on GitHub”!

Support for 1d meshes

MDAL and QGIS now supports 1D meshes, currently for UGRID and 3Di formats. Other formats should be easy to add. If you are interested in supporting a format, drop us a line.

You can read the full technical description in the following QGIS Enhancement Proposal.

The 1D meshes can be styled with the various renderers, for example use of pressure data to calculate line width:

Furthermore, Crayfish plugin has been extended to support such mesh data frames. For example, 1D plots in Crayfish with the snapping and routing along the network can be used:

2D mesh rendering improvement

2D meshes streamlines/particles/arrows can be now styled by the colour ramp. You can better display streamlines and mesh vectoral data varaition:

Meshes in 3D map view

The mesh layer is now fully supported in the 3D map view. You can visualise your terrain and overlay vector arrows (e.g. velocity) and other mesh quantities (e.g. water surface) in the 3D map view.

Other features and bugfixes

QGIS

• The mesh rendering speed increased by 2-20 times depending on various mesh/zoom/map/data combinations
• Ability to show only subset of dataset groups in the Mesh styling window
• Support for reading multiple meshes in one file (e.g. UGRID)
• Ability to resample vertex values to faces
• Support for saving/loading of QML styles
• Full usage of temporal controller, even in print templates, animation, …

MDAL

• The GRIB and NetCDF datasets are now loaded twice as fast
• Support for UGRID datasets with magnitude and direction
• Support for reading of UGRID classified data and its usage in QGIS color ramps
• Renamed the pointers and functions in the API for consistency
• Created brand new logo and started the online-docs
• Support XMS Tin

Crayfish

• Ported to new temporal API
• Added 1D plots
• Fixed various UI bugs

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Mergin Maps, a field data collection app based on QGIS. Mergin Maps makes field work easy with its simple interface and cloud-based sync. Available on Android, iOS and Windows.

After a successful crowdfunding campaign to support Vector Tiles in QGIS, we have been busy adding new features for the upcoming release (3.14).

In this blog post, we are exploring different methods to add your vector tiles and style them.

Loading data - local files

If you have an MBTiles file containing vector tiles, you can simply drag and drop the layer in QGIS. Alternatively, you can connect to a local vector tile file(s) from the Data Source Manager or the Browser Panel. As an example, you can use this QGIS project which contains Switzerland vector tiles (maximum zoom level =14).

You can also test this project on your mobile device. Download Input app (for iOS you need the TestFlight version of the app), head to Projects > Explore and download saber\blogpost-vectortile.

Loading data - web resources

You can access vector tiles served through the web. You need to have the URL and possibly API key to add them in your QGIS. In the example below, vector tiles from MapTiler are added to QGIS:

To use MapTiler data, we recommend using their dedicated QGIS plugin, which comes with vector tiles in different styles. The plugin should be available on the QGIS plugin repository.

Styling data

Vector tiles contain points, line and polygon geometries. You can define a set of rules for features and apply style and label. Style and labelling can be dependent on the zoom level. Similar to vectors and rasters, styles for vector tiles can be stored in QML format. To set up filters, you can use the identify tool in QGIS to inspect geometries of your vector tile:

Currently, the most common format to store vector tiles styles are Mapbox GL (json). The OpenMapTiles repo contains some excellent Mapbox GL styles. We initially developed a tool to convert the json files to QGIS style. The plugin has been further extended and developed by MapTiler to better handle the OpenMapTiles data schema. This will ensure future changes to the data schema will be addressed by the plugin.

Example of styles converted from Mapbox GL to QGIS from Maptiler QGIS plugin

In the next post, we will explore different options within QGIS or other 3rd party tools to generate vector tiles.

Credits

All the data used in this blog post was from OpenStreetMap server by Geofabrik. OpenMapTiles conversion tool was used to generate the tiles from OpenStreetMap to vector tiles. See software license for more details.

The following OpenMapTiles Mapbox GL styles Bright, Positron, Basic and Fiord were converted using mapbox2qgis and QGIS MapTiler plugin.

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Mergin Maps, a field data collection app based on QGIS. Mergin Maps makes field work easy with its simple interface and cloud-based sync. Available on Android, iOS and Windows.

We introduced a new packaging and build environment for QGIS and its dependencies for macOS. This will bring a completely new experience for QGIS macOS developers and subsequently, the users.

Overview of the changes

• What is new?
• QGIS development on macOS
• Development of the QGIS-Deps package
• Next steps

What is new

In 2019, we upgraded the QGIS macOS packaging to address several issues at the time. This was made possible with the help of the QGIS project and donors who supported our work.

The upgraded system had a more transparent and automated packaging approach. But it came with its own limitation. We have been using Homebrew to fetch the QGIS dependencies and to compile only QGIS for the LTR, PR and nightly releases. The main problems with this approach are:

• Homebrew can only support one version of a package. This will limit QGIS to be built against multiple versions of, for example GDAL or Proj libraries. In one hand, we want QGIS nightlies to use more bleeding edge versions of the dependencies (e.g. for plugin or core developers) . On the other hand, using a more stable and tested versions of the dependencies for PR or LTR are not recommended (e.g. users and organisations). OSGeo4W offers the same approach for different versions of QGIS in Windows. Unfortunately, Homebrew does not offer such an option.

• Continuous integration has been a major part of QGIS infrastructure to ensure pull requests by developers do not break workflows in certain Operating Systems. Microsoft Windows and Linux have been well supported in the CI. But with the macOS packages, it was left to user to test and report back any bugs after Pull Requests were merged to QGIS source code.

With the recent work, we have addressed both of the above issues. QGIS and almost all of its dependencies are built from sources. It will be also possible to easily integrate the code with the current CI for macOS with GitHub Workflows. This will bring more stability and control over the way we build and package QGIS for our users, whilst helping developers to identify issues with their pull requests for macOS platform, before merging them to the QGIS source code.

QGIS development on macOS

If you want to check the latest QGIS master on macOS or tweak the code to see some new exciting features, now it should be easier with the following steps, to compile QGIS from source code an a clean machine:

1. Install XCode

• Upgrade to latest MacOS version
• Install latest XCode from the official AppStore
• Open XCode and accept license
• Install command line tools from XCode, AppStore or from command line by sudo xcode-select --install

2. Install Qt and QGIS-Deps

• Download the latest install qgis-deps script and check the version of Qt required
• Install the required Qt version referenced from the official Qt download area. Or alternatively download qt-version.tar.gz from deps area
• Download latest qgis-deps package too.
• Run install_qgis_deps.bash script to install Qt in /opt/Qt/5.14.1/clang_64 and QGIS-Deps to /opt/QGIS/qgis-deps-0.3.0 folder. You may need to use root privileges or create those folders under /opt/ and assign the right permission beforehand.

3. Install other tools

• Install Homebrew
• Install minimal set of packages required for macOS build tools listed in this list

You may use MacPorts, Conda or other packaging system, but by the end you need cmake, git, astyle and other useful tools to be on the system PATH

4. Download and compile QGIS

• Open the terminal (Note that the qgis-deps package is not yet signed, so you may need to add Terminal to System Preferences -> Security & Privacy -> Privacy -> Developer Tools)
• In your work folder (e.g. ~/Projects/), clone QGIS with git clone git@github.com:qgis/QGIS.git
• Create a build folder mkdir -p ~/Projects/build-QGIS
• Go to the created empty directory cd ~/Projects/build-QGIS
• Run CMake to generate the build system (use your download qgis-deps and qt package)

  QGIS_DEPS_VERSION=0.3.0;\
  QT_VERSION=5.14.1;\
  PATH=/opt/QGIS/qgis-deps-${QGIS_DEPS_VERSION}/stage/bin:$PATH;\
  cmake -DQGIS_MAC_DEPS_DIR=/opt/QGIS/qgis-deps-${QGIS_DEPS_VERSION}/stage \
      -DCMAKE_PREFIX_PATH=/opt/Qt/${QT_VERSION}/clang_64 \
      ../QGIS
  

Note that all libraries are picked from qgis-deps and not from system /usr/lib or Homebrew’s /usr/local/ or system Frameworks /Library/Frameworks/. Especially check Proj, GDAL, sqlite3 and Python paths. You should see output similar to this:

-- QGIS version: 3.13.0 Master (31300)
-- Found OpenCL: /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.15.sdk/System/Library/Frameworks/OpenCL.framework (found version "1.2")
-- Found OpenCL C++ headers: /Users/peter/Projects/mesh/QGIS/external/opencl-clhpp/include
-- Found GRASS 7: /opt/QGIS/qgis-deps-0.3.0/stage/grass78 (7.8.2, off_t size = 8)
-- Looking for openpty
-- Looking for openpty - found
-- Found Proj: /opt/QGIS/qgis-deps-0.3.0/stage/lib/libproj.dylib version 6 (6.3.1)
-- Found GEOS: /opt/QGIS/qgis-deps-0.3.0/stage/lib/libgeos_c.dylib (3.8.1)
-- Found GDAL: /opt/QGIS/qgis-deps-0.3.0/stage/lib/libgdal.dylib (3.0.4)
-- Found Expat: /opt/QGIS/qgis-deps-0.3.0/stage/lib/libexpat.dylib
-- Found Spatialindex: /opt/QGIS/qgis-deps-0.3.0/stage/lib/libspatialindex.dylib
-- Found Qwt: /opt/QGIS/qgis-deps-0.3.0/stage/lib/qwt.framework (6.1.4)
-- Found LibZip: /opt/QGIS/qgis-deps-0.3.0/stage/lib/libzip.dylib
-- Found libzip: /opt/QGIS/qgis-deps-0.3.0/stage/lib/libzip.dylib
-- Found Sqlite3: /opt/QGIS/qgis-deps-0.3.0/stage/lib/libsqlite3.dylib
-- Found Protobuf: /opt/QGIS/qgis-deps-0.3.0/stage/lib/libprotobuf.dylib (found version "3.11.4")
-- Found Protobuf: /opt/QGIS/qgis-deps-0.3.0/stage/lib/libprotobuf.dylib
-- Found ZLIB: /opt/QGIS/qgis-deps-0.3.0/stage/lib/libz.dylib (found version "1.2.11")
-- Found zlib: /opt/QGIS/qgis-deps-0.3.0/stage/lib/libz.dylib
-- Found PostgreSQL: /opt/QGIS/qgis-deps-0.3.0/stage/lib/libpq.dylib
-- Found SpatiaLite: /opt/QGIS/qgis-deps-0.3.0/stage/lib/libspatialite.dylib
-- Qt WebKit support enabled
-- Found Qt version: 5.14.1
-- Found QScintilla2: /opt/QGIS/qgis-deps-0.3.0/stage/lib/libqscintilla2_qt5.dylib (2.11.4)
-- Found QtKeychain: /opt/QGIS/qgis-deps-0.3.0/stage/lib/libqt5keychain.dylib
-- Found QCA: /opt/QGIS/qgis-deps-0.3.0/stage/lib/qca-qt5.framework (2.3.0)
-- Found QCA OpenSSL plugin
-- Found Libtasn1: /opt/QGIS/qgis-deps-0.3.0/stage/include
-- Pedantic compiler settings enabled
-- Found PythonInterp: /opt/QGIS/qgis-deps-0.3.0/stage/bin/python3 (found suitable version "3.7.7", minimum required is "3")
-- Found Python executable: /opt/QGIS/qgis-deps-0.3.0/stage/bin/python3
-- Found Python version: 3.7.7
-- Found Python library: /opt/QGIS/qgis-deps-0.3.0/stage/lib/libpython3.7m.dylib
-- Found Python site-packages: /opt/QGIS/qgis-deps-0.3.0/stage/lib/python3.7/site-packages
-- Found PyQt5 version: 5.14.1
-- Found SIP version: 4.19.21
-- Found QScintilla2 PyQt module: 2.11.4
-- txt2tags not found - disabled
-- Performing Test COMPILER_HAS_HIDDEN_VISIBILITY
-- Performing Test COMPILER_HAS_HIDDEN_VISIBILITY - Success
-- Performing Test COMPILER_HAS_HIDDEN_INLINE_VISIBILITY
-- Performing Test COMPILER_HAS_HIDDEN_INLINE_VISIBILITY - Success
-- Performing Test COMPILER_HAS_DEPRECATED_ATTR
-- Performing Test COMPILER_HAS_DEPRECATED_ATTR - Success
-- Found exiv2: /opt/QGIS/qgis-deps-0.3.0/stage/lib/libexiv2.dylib
-- HDF5: Using hdf5 compiler wrapper to determine C configuration
-- Found HDF5: /opt/QGIS/qgis-deps-0.3.0/stage/lib/libhdf5.dylib;/opt/QGIS/qgis-deps-0.3.0/stage/lib/libz.dylib;/usr/lib/libdl.dylib;/usr/lib/libm.dylib (found version "1.10.0")
-- Found PkgConfig: /usr/local/bin/pkg-config (found version "0.29.2")
-- Found NetCDF: /opt/QGIS/qgis-deps-0.3.0/stage/lib/libnetcdf.dylib
-- Found LibXml2: /opt/QGIS/qgis-deps-0.3.0/stage/lib/libxml2.dylib (found version "2.9.10")
-- Looking for updwtmpx
-- Looking for updwtmpx - not found
-- Found GSL: -L/opt/QGIS/qgis-deps-0.3.0/stage/lib -lgsl -lgslcblas
-- Using PROJ 6 srs database.
-- Ctest Binary Directory set to: /Users/peter/Projects/mesh/build-QGIS/output/bin
-- Configuring done
-- Generating done
-- Build files have been written to: /Users/peter/Projects/mesh/build-QGIS

• Compile QGIS make -j4 and wait for [100%] mark :)
• Now you can run QGIS with command ./output/bin/QGIS.app/Contents/MacOS/QGIS or open ./output/bin/QGIS.app

Notes:

• If you use QT Creator, you can open already generated project to modify files from it.
• The critical CMake variable is QGIS_MAC_DEPS_DIR and you must ensure it contains valid qgis-deps installation
• You can add more variables to CMake command to tweak the build settings, e.g. enable 3D with ‘-DWITH_3D’, etc.
• Consult QGIS’s [INSTALL]https://github.com/qgis/QGIS/blob/master/INSTALL) for latest developement tips

Development of the QGIS-Deps package

If you want to help with development of the qgis packages on macOS, please feel free to contact peter.petrik@lutraconsulting.co.uk. The development is taking place on public QGIS-Mac-Packager repository.

Next steps

Currently, we are carrying out the following tasks:

• to move all-in-one QGIS bundle for LTR/PR/nighlies to use this new package of dependencies. Check out Twitter for for any news on the packages. We are aiming to have the new packaging in place for the QGIS 3.14 release, which will bring GDAL 3 and Proj 6 to macOS users

• to sign the qgis-deps packages, so that developers do not need to tweak Privacy settings to use it for compiling QGIS and its dependencies.

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Mergin Maps, a field data collection app based on QGIS. Mergin Maps makes field work easy with its simple interface and cloud-based sync. Available on Android, iOS and Windows.

We are delighted to announce that the crowdfunding to support Vector Tiles in QGIS has been successful!

Here is the list of donors who have supported us and the wider QGIS user by funding this feature.

List of donors

(in no particular order)

• GISassistANS AB
• QGIS ITALIA
• Bright Rain Solutions
• GIS Support sp. z o.o.
• Andreas Neumann
• ZT-Buero Weissbacher
• geoco
• BNHR
• Daniel! :)
• Hobu, Inc.
• Webmapper
• Ghislain GREGOIRE
• Jorrit Jorritsma
• Zhi Keng He
• Gregory Hall
• Dirk Voets
• OSGeo:UK
• Correlate Analytics gmbh
• Roy Rathbun
• Terence Dodge
• MapTiler (the OpenMapTiles team)
• Jin Igarashi
• Location Strategy LLC
• Common Data Solutions, LLC
• Syed Gardezi
• Casey Ghilardi
• MaptIQ Consulting Ltd
• Animus Technology
• WhereGroup GmbH
• Hans van der Kwast
• Farallon Geographics
• LonLat OÜ
• MIERUNE Inc.
• QLX GmbH
• Mohammed ZAHRAN
• Torben Scharm
• Paul-Benjamin Riedel
• FISOTEC

Also many thanks to those who spread the word and offered us moral support!

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Mergin Maps, a field data collection app based on QGIS. Mergin Maps makes field work easy with its simple interface and cloud-based sync. Available on Android, iOS and Windows.

In this post, we will use Input app to record tracks. The first step is to set up a project in QGIS.

Quick recap

In the previous tutorial, we set up a simple QGIS project and transferred it to our devices using the Mergin service.

In this tutorial we are going to set up a new survey project with more advanced features:

• Forms with more options
• Different background layers (aerial imagery and street map)
• Using different geometry type of survey layer
• Exploring other Input app functions

Software needed

To start with, you will need to install the following software applications:

• QGIS - for your PC/laptop: download and install QGIS if you have not already done so
• Input app - for your mobile table: you can download the app from Google Play Store or Apple’s App Store

In addition, you will need to register with the Mergin service. The Mergin service allows you to transfer data between your PC/laptop and mobile/table via the cloud. Note that after signing up to the Mergin service, you have to activate the account by clicking on the link sent to your email.

Configuring QGIS project

Similar to the previous tutorial, we are going to start with a blank QGIS project. All the data and the project will be stored locally on a folder called recording tracks.

First, start a QGIS project and add the OpenStreetMap layer under XYZ Tiles. You can add also add aerial imagery as an XYZ layer to your QGIS.

Save your project as tracks in the recording tracks folder.

In addition, we need to create a Geopackage survey layer. Below are the attribute columns for your survey layer. Also note that need to select Line as geometry type.

To create a survey layer, in QGIS, from the main menu select Layer > Create Layer > New Geopackage Layer …. A new window will appear:

For Database click on … and select the recording tracks folder then type survey.gpkg for the name of your database.

For Table name, type tracks.

For Geometry type, select Line.

You can select the option to Include Z dimension. The upcoming version of Input app supports capturing altitude from your device (or external GPS device tethered with your phone/tablet).

For Coordinate Reference System (CRS), select WGS 84 / Pseudo-Mercator EPSG:3857.

Add the following Fields. Note, different field types:

• Type field type as text
• Public field type as Boolean or bool
• Photo field type as text
• Date field type as Date & time

Click OK to create and add the layer to your QGIS session.

Styling layers and setting up forms

We are going to style the tracks layer based on Type field and use four categories:

• Footpath
• Byway
• Cycle path
• Bridle way

In the Layer Panels right-click on tracks layer and select Properties. A new window will appear. From the left panel, select Symbology. Change the styling from Single to Categorized on the top left section of the window. For the Value, select Type from the drop-down menu.

In the bottom-left section of the window, click on Classify. Then add 4 classes (by adding the green plus adjacent to Classify) for track types. In addition, we can add another class for Other types. Adjust the colours and line style accordingly:

To set up the form, select Attribute forms from the left panel of the layer properties window. Adjust the Widget type as below:

• For fid, select Hidden
• For Type, select Value map and add the 5 categories (Footpath, Byway, Cycle path, Bridle way and Other) for Value and Description section (see image below)
• For Public, select Checkbox
• For Photo, select Attachment and select the option for Relative path
• For Date, select Date/Time

Input app allows you to have a custom pop-up drawer window when you tap on feature. To customise that, you can change the Display settings under the layer properties window. For Display name select Type and in the HTML Map Tip section type:

# image file:///[%@project_folder%]/[% "Photo" %]

Setting up map themes

We can set up two different map themes: one with aerial imagery and one with street map. To do that, ensure you have only the following layers are set to visible in your layer panel:

• tracks
• Aerial images

On top of the layers panel, select Manage Map Themes > Add Theme …

A new window will appear. Type Aerial photo for the name of your map theme and press OK.

Now, turn off your Aerial images layer in the layer panel and turn on the OpenStreetMap layer:

You can now add a new map theme and call it Street map.

Save your project and transfer your data and project to your phone through the Mergin service as described in the previous tutorial.

If you missed a step, you can see the final version of the project here. You can also skip the above section by cloning the project in the above link.

Recording tracks using Input app

In Input app, download and open Tracks project.

You can easily change between different map themes in Input, by going to (… More) > Map Themes:

To capture tracks, press Record button in the lower panel in Input. A green cross will appear, centred on your GPS location. You can capture a line in two different methods:

• Adding points to form the line by moving the map and pressing Add Point
• Streaming GPS location while moving to form a line. To do that, press and hold GPS icon on the bottom left of your screen (see image below)

You can change the frequency of adding points when streaming GPS location, under Settings in Input. Also note that the GPS streaming can be done for polygon survey layer.

Once you finished capturing the track, press Done and you will be presented with a form:

You can easily fill the form using the drop-down menu for Type and checkbox option for Public.

By tapping on tracks on the map, you will should be able to see a small preview window presenting Type and Photo:

After completion of the survey, you can synchronise your data back through the Mergin and see the results in QGIS desktop.

In an earlier blog post, we looked into how to visualise rasters and terrains in QGIS 3D.

In this post, we will explore 3d vectors and how to view buildings and trees.

Data Sources

For the purpose of this blog post, we will be using

• Buildings dataset.
• Background vector data and tree points.
• Terrain data.

You can download all the dataset and final QGIS project from our Mergin service. Note that the DTM has been resized from 1m resolution to 5m. All of the datasets have been clipped to Luxembourg commune extent.

After styling the layers you should be able to see an image like the one below in your map view.

3D Buildings

You can open a new 3D map window and set the DTM layer as your terrain as shown in the earlier blog post.

The other layer we want to view in 3D canvas is the building layer. To adjust the settings, you need to change the layer styling (by pressing F7 to open the styling panel):

• By default, the 3D rendering of vector layer is set to No symbol. Click on it and set it to Single symbol.

The buildings layer contain height information:

• Change Altitude clamping to Absolute.
• Change Altitude binding to Vertex.

In case, your building layer is not a 3D dataset, you can apply height and/or extrusion to be able to see them in 3D map view.

Culling mode helps rendering your scenes faster by not drawing certain features facing the camera. You can read more about culling modes here and here.

You can change Diffuse, Ambient, Specular and Shininess of the polygons using relevant widgets. These parameters are based on Phong reflection model.

Finally to better display the buildings, you can define the Edges.

You should be able to see a 3d scene similar to the one below:

3D Points

Points can be displayed in 3D map view as different type of objects. In this example, we are going to display trees as combination of predefined shapes. You can extract tree points from the OpenStreetMap data (the osm_pois layer with filter: "fclass" LIKE 'tree').

For tree trunks, we can set the 3D properties as follows:

The tree trunks are represented by a Cylinder shape. As you have noted, the Altitude clamping method for this layer is Relative.

For the tree top, we can duplicate the same tree layer in the layer panel and change the styling to be a Sphere shape. You will also need to set the Transformation for Y to e.g. 10, so that the spheres sit on top of the cylinders. For the example below, we have set the styling to be a mix of spheres and cones (Rule-based instead of Single symbol).

3D point renderer allows you to import 3d models supported by Open Asset Import Library.

Fly-over animations

You can create animations of 3d scenes, by defining key frames. Click on the Animation icon from the 3D map view window. A new toolbar will appear at the bottom of your window.

Click on the green plus sign to add the timing of the key frames and then move the camera to a different location. You can then play the fly-over using different interpolation methods. Alternatively, you can export them as images and generate an animation outside QGIS.

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Mergin Maps, a field data collection app based on QGIS. Mergin Maps makes field work easy with its simple interface and cloud-based sync. Available on Android, iOS and Windows.

We are happy to announce a new crowdfunding campaign to support Vector Tiles in QGIS!

This will be a great step for QGIS to support an increasingly popular technology used in web mapping to deliver maps that are faster and more flexible at the same time.

With native support for Vector Tiles in QGIS, you will be able to add more resources to your QGIS map:

• Support for remote resources (e.g. HTTP/HTTPS map tiles)
• Handling local vector tiles (in XYZ format)
• Handling database vector tiles (Mapbox Vector Tiles format)

The target amount is 8,000 € and the campaign will be active until 20 March 2020.

Please have a look at the dedicated page Vector Tiles support in QGIS for further details and help us spread the word!

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Mergin Maps, a field data collection app based on QGIS. Mergin Maps makes field work easy with its simple interface and cloud-based sync. Available on Android, iOS and Windows.

In this post, we will walk you through basic steps to set up a survey project in QGIS desktop and using it in Input app to collect data in field using your Android or iPhone/iPad device.

Software needed

To start with, you will need to install the following software applications:

• QGIS - for your PC/laptop: download and install QGIS if you have not already done so
• Input app - for your mobile table: you can download the app from Google Play Store or Apple’s App Store

In addition, you will need to register with the Mergin service. The Mergin service allows you to transfer data between your PC/laptop and mobile/table via the cloud. Note that after signing up to the Mergin service, you have to activate the account by clicking on the link sent to your email.

Configuring QGIS project

To be able to survey data, we need to set up a project in QGIS. Usually, you will need some data for your background layer (so that you can locate yourself!). In addition, you need to set up a table (or layer), to store your survey information.

For background data, we are going to use Open Street Map. For survey table, we need to decide on a form structure and the type of feature you want to survey (e.g. point of interest, tracks or parcel of land). In this case, we want to survey potholes. Also, it would be good to attach some notes for each pothole, take a photo of it and add a date for survey. The GIS format best suited to store spatial information, is Geopackage.

Let’s start by opening QGIS and add the above layers to our project. To simplify things, we can create a folder on Desktop (referred to in this tutorial as data collection folder) and store everything there.

Open QGIS from your PC/laptop. From the Browser panel (usually located on the top left side), expand XYZ Tiles and double-click on OpenStreetMap to add it to QGIS:

You should see the OSM layer:

Save your project as pothole survey in the data collection folder.

To create a survey layer, in QGIS, from the main menu select Layer > Create Layer > New Geopackage Layer …. Note that Geopackage is a file based database where you can store multiple tables (spatial or non-spatial). A new window will appear:

For Database click on … and select the data collection folder on your Desktop and then type survey-db.gpkg for the name of your database.

For Table name, type Potholes.

For Geometry type, select Point.

For Coordinate Reference System (CRS), click on the icon to the right of EPSG:4326 - WGS84. A new window will appear. Under Filter section on the top of the window, type: 3857 and under Predefined Coordinate Reference Systems, select WGS 84 / Pseudo-Mercator EPSG:3857. Then click OK.

We can now create the column headers for our table under New Field section. For this form, we want to create the following columns to store data: Date, Notes, Photo

For Name, type Date

For Type, select Date

Click on Add to Field lists to add your column.

Repeat the same process for Notes and Photos columns, but make sure to change the Type for those columns to Text. At this stage, you should see an image similar to the one below:

Go ahead and click OK to create the layer and add it to QGIS.

Styling layers and setting up forms

The default style applied to Potholes layer is not very visible probably. To change it:

In the Layer Panels right-click on Potholes layer and select Properties. A new window will appear. From the left panel, select Symbology. Try to change the style to something shown in the image below:

Click on Apply.

We can also change the way user fills in the form. By default, you have to type in the values. But by using different widgets, we can simplify filling the form in the field.

In the Properties window, from the left panel, select Attribute forms.

We are going to change the Widget Type for each of the Fields.

fid is an auto-increment field and we can keep it hidden from users. So, highlight the fid field under Field section and then from the Widget Type select Hidden

For Data, it should have automatically selected the correct widget type:

For Notes, you can also leave the Widget Type as Text Edit.

For Photos, we need to change the Widget Type to Attachment. Also make sure to select the option for Relative paths. This will allow us to attach photos using mobile camera or gallery folder to the pothole point.

Tip: You can scroll further down and under Integrated Document Viewer and select Type as Image. This will show the image in QGIS forms too.

Project set up is completed and we can save the project.

Transferring data to mobile devices

You have 2 options to transfer your data to the mobile through the Mergin service: through website or through Mergin plugin in QGIS. In this tutorial we are going to use the plugin from within QGIS.

In QGIS, from the main menu, select Plugins > Manage and Install Plugins …. A new window will appear. From the left panel, select All and then in the search section (on the top) search for Mergin. Select the plugin from the list and click on Install plugin. After installation, you need to restart your QGIS.

After the restart, you should be able to see the Mergin icon in your Browser Panel:

In the Browser Panel, right click on the Mergin and select Configure. Type in your username (or email address) and password that you have registered with the Mergin service.

Click on Test Connection and you should see a green OK.

If you have selected to Save credentials (so you do not need to type in the username and password again) and you have not configured QGIS password manager, you will be prompted to set a password for your QGIS password manager.

After clicking OK, you should see a list of folders on your Mergin connection in your browser panel:

We can know upload the data:

Right click on the Mergin and select Create new project. A new window will appear:

For Project name type Potholes survey

Select Initialize from local drive

Click on … and and select data collection folder

Once click OK, the project will be created and content of the data collection folder will be uploaded there.

The project is now ready to be downloaded on your mobile device.

Collecting data using Input app

The project can now be accessed from Input app. Open your Input app and for the first time you should see a screen similar to the image below:

To log in to the Mergin service, you can select My projects or the green and white icon on the top right.

Type your Mergin username (or email address) and password and then select Sign in.

Once signed in, select My projects and you will see Potholes survey project in the lists

Select the download icon on the right side of Potholes survey to download your project on the phone and make it ready for survey.

After downloading is completed, select Home and you should be able to see Potholes survey.

Select Potholes survey and it will open the map:

To record a feature, select Record button and the pointer changes to a cross-hair.

By default, the cross-hair centres to your location (the orange point) on the map. You can move the map and adjust the location. To recentre the map to your location, you can select GPS button. Once you are happy with the location, you can select Add point and the form for your point will appear:

Fill in the form and press Save. You should see the map with the newly captured pothole:

Synchronising data

The data you have captured on your phone can be synchronised through the Mergin service.

In Input app, select Projects and then My projects. You should see a double arrow on the right side of the Potholes survey.

Select the double arrow to sync your project. You can also open QGIS from your PC/laptop and synchronise changes back to your desktop:

In QGIS, from the Browser Panel under Mergin > My projects right-click on Potholes survey and select Synchronize

After synchronising is completed, you should be able to see the point and its associated form on your QGIS.

Further reading

Input app’s manual can be found here.

With the Mergin service, multiple users can collect data on the same project. For more information, see this the blog post.

For more information on how to set up complex forms and map themes see QGIS documentation.

Ready for 3D meshes, vector streamlines or contour export?

The releases of QGIS 3.12, MDAL 0.5.0 and Crayfish 3.2.1 are planned for end of February 2020. We are proud to present you few of upcoming features we implemented for this release:

• vector trace animation
• 3D stacked meshes
• mesh calculator enhancements
• export contours
• various smaller enhancements (reference time support, resampling, export plot data, mdal_translate utility)

If you are hesitant to wait till end of February, feel free to get nightly build and test it out!

Do you want to use QGIS Mesh Layers in your projects? Read more…

Support for vector trace animation and streamlines (QGIS)

Last feature from QGIS 2.x/Crayfish 2.x series that was not ported to QGIS 3 is finally available. You would be able to visualize streamlines and particles for vector datasets in mesh layers. In QGIS main menu, under Mesh>Crayfish>Export Trace you are also able to export animation with the particle traces to various video formats

This feature was funded by TUFLOW

Support for 3d Stacked Meshes (e.g. TUFLOW FV format)

MDAL and QGIS now supports 3D Stacked Meshes, particularly for TUFLOW-FV format. For this release, you need to choose appropriate averaging method in the QGIS interface and you are able to browse the data similarly to any other 2D dataset.

In Crayfish 3.2.1, you can create plots of the profile showing the variation along Z-axis.

The technical description can be found in the following QEP

This feature was funded by TUFLOW

On the fly resampling of data defined on faces to vertices

For datasets defined on faces, one can choose to interpolate data to vertices with neighbour average method. When no data interpolation method is chosen, each pixel on a single face has a single value/color. With data on vertices, the rendering for each pixel is interpolated from the values on the vertices, making smoother figures.

Use mesh contours styling panel to switch between the data interpolation methods.

This feature was funded by Austrian Ministry of Agriculture, Forestry, Environment and Water Management

Smooth export of the contours (Crayfish processing algorithm)

We have implemented a new algorithm in QGIS’s analysis library to export directly contour lines and polygons. The method is not based on GDAL as it was in the Crayfish 2.x releases. It is both faster and with smoother shapes, matching rendered images from QGIS. You can find the new processing algorithm in Crayfish processing toolbox.

This feature was funded by Austrian Ministry of Agriculture, Forestry, Environment and Water Management

Support of datasets defined on faces in QGIS Mesh Calculator

From QGIS 3.12 you can use mesh calculator for all datasets, both defined on faces and vertices. Additionally, it allows users to store the result of mesh calculator under different name or format. This allows for example to work with FLO-2D or HEC-RAS data in the QGIS mesh calculator

This feature was funded by Austrian Ministry of Agriculture, Forestry, Environment and Water Management

Support for reference time (QGIS)

For various dataset type, for example GRIB and NetCDF, the reference time in QGIS time settings dialog is prepopulated from the raw data and does not need to be set manually. Also we fixed various bugs related to time parsing, so in QGIS 3.12 it should be possible to format and show your time in plots/animations in proper way.

This feature was funded by TUFLOW

Support for conversion of 2dm to UGRID mesh (mdal_translate utility)

MDAL library now has a new utility: mdal_translate. For now, use can use the utility to convert text-based 2dm mesh definition files to UGRID NetCDF/HDF5 binary-based format and save up to 80% disk and speed up loading of your mesh by similar amount.

This feature was funded by TUFLOW

Support for export of 2D plot data (processing)

With Crayfish 3.2.1 you can export your time series or cross section raw dat to CSV format for further processing.

This feature was funded by Lutra Consulting

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Mergin Maps, a field data collection app based on QGIS. Mergin Maps makes field work easy with its simple interface and cloud-based sync. Available on Android, iOS and Windows.

The latest beta release of Input (v.0.4.90) comes with smart diff support for vectors. This will allow you to use the app (current beta version) in a collaborative environment, where several users can make changes to a single survey layer (geopackage).

What does it mean?

It is often the case, where multiple users need to make changes to a single vector layer. If you work in office, this issue is usually addressed by having a central geodatabase (e.g. Postgres/PostGIS). If you want extra information (e.g. audit trails, versioning, latest changes, etc), you can modify your database, to keep track of it.

The problem arises when you want to collect data, without having access to the central geodatabase. You can do some manual work to handle this scenario, but it can easily lead into data management nightmare.

To simplify the workflow, we have developed Geodiff, a multi-platform library to keep track of changes, calculate the differences, merge and consolidate the differences.

How can I use it?

Geodiff has been integrated into the beta version of Input. This will allow you to share a project with your team and edit a single layer (geopackage format) all at the same time, even when you are offline.

To start with, you need to create a project and upload it to Mergin. You can then share the project (with write access) with your colleagues:

The project contains a survey layer (trees.gpkg). There is only one feature present within the layer:

The project is shared with two users. Both users download the project and take their devices to the field:

User 1, carried out a survey (using iPhone!), by adding a tree and editing the attribute table of the existing one. The changes were synchronised back through the Mergin:

Meanwhile, User 2 added a new feature to the survey layer. Once User 2 tries to synchronise the changes, Input automatically detects the changes not only made through User 2, but also the ones uploaded to the Mergin. The layer will be patched both locally and on the server to take all the changes into account:

The data administrator can now pull all the changes from both users in QGIS:

You can also see the history of changes to the project and the survey layer on the Mergin website. Below shows the changes from different users:

To see changes from each user, you can click on the version and it lists the changes. In this example, User 1 (jack) added a new feature and modified an existing feature:

You can also see the extended history and see where the changes have been made:

How can I test this new feature?

You can use Beta version of Input app in Android or TestFlight in iOS:

For any issues or feedback, please file a ticket on Input repository