This article is a quick start guide on how to use PIX4Dmatic for the first time. In particular, this page will show how to get from an image dataset captured by a drone or PIX4Dcatch RTK to the creation of accurate 2D and 3D maps and models.
IN THIS ARTICLE
Setting up a project Log in
Create new project
Import Tie points
Coordinate Reference System
Image Coordinate Reference system
GCPs Coordinate Reference System
Project coordinate system
Calibration
Dense point cloud
Planes
Mesh
DSM
Orthomosaic
Video tutorials
Introduction to the PIX4Dmatic interface |
How to process aerial imagery with PIX4Dmatic |
How to process PIX4Dcatch data with PIX4Dmatic |
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Setting up a project
The first step in PIX4Dmatic is setting up the project, defining the required parameters, and adding the necessary data before moving on to processing.
Log in
Sign-up for a Pix4D account or use the existing Pix4D account to log in to the software.
- Click icon or Log in on the top right side of the screen.
- Enter the Email and click Continue.
- Enter the Password and click Log in.
Create new project
New projects in PIX4Dmatic can be created by dragging and dropping images or image folders on the home screen, using the menu bar, or the Ctrl + N (⌘ + N) shortcut.
Drag and drop input files
- Drag and drop images or image folders on the home screen.
- Specify the Project name and the Path of the project.
- Click Start.
A new project is created and ready for processing. To import additional input files use the File menu or drag and drop them on the screen.
For more information: Create a project - PIX4Dmatic
Import Tie points (GCPs and CPs)
Adding and marking Tie points (Ground control points (GCPs) and Checkpoints (CPs)) in a project is optional but it's a method to maintain and verify the absolute accuracy of a project.
For more information on Tie points: Tie points - PIX4Dmatic
For more information on how to mark Tie points: Mark Tie points - PIX4Dmatic
There are three methods to import a tie point .csv/.txt file into PIX4Dmatic. One is accessible through the File tab in the main header, and the others are accessible from the Tie Points panel.
- [1] Go to the Menu bar and select File > Import GCPs... to select the GCP file.
- Click the Tie points (0) tab on the lower right of the screen to expand the tab.
- [2] Drag and drop the GCP file, or Select from disk to specify the GCP file.
- [3]Click the dropdown menu and select Import GCPs...
- Select the tie point file.
Tie points can be imported and marked at different stages:
- Before the Calibration step: This requires more manual work as the position of Tie Points on images is not precise as it is determined only based on the initial image geolocation and orientation. However, marking the Tie Points before processing can eliminate the need for reprocessing or reoptimizing the Calibrate step.
- After the Calibration step: The position of Tie Points on images is more precise as external and internal camera parameters are calculated. However, you will need to reprocess or reoptimize the Calibrate step.
Coordinate Reference System
After importing the images and the Tie points, the Coordinate Reference System (CRS) must be set. PIX4Dmatic allows setting the CRS of the Images, the GCPs, and the Project.
Image coordinate reference system
PIX4Dmatic allows the image coordinate system to be manually set or edited.
To edit the image horizontal or vertical coordinate systems, click on the edit icon in the lower right corner of the screen where the Cameras tab is.
After clicking on the edit icon, the Set image coordinate reference system (CRS) dialog box will open.
Unless a camera is in the PIX4Dmatic camera database or the images have the correct XMP tags, the default image coordinate system is WGS84 (EPSG: 4326) for the horizontal and EGM96 (EPSG: 5773) for the vertical.
GCPs coordinate reference system
Both the horizontal coordinate system and the vertical coordinate system can be defined in the Tie Points table:
The GCP coordinate reference system (CRS) window will pop up.
To select the horizontal coordinate reference system:
- In the Horizontal coordinate reference system dialog, search or copy-paste:
- The name or
- The EPSG code of the coordinate system.
To select the vertical coordinate reference system:
- In the Vertical coordinate reference system dialog, search or copy-paste:
- The name or
- The EPSG code of the coordinate system.
- (Optional) Geoid: If the selected vertical coordinate system supports geoids and the geoid model is available in the PIX4Dmatic database, select the geoid model in the drop-down list.
- (Optional) Geoid height: If the selected vertical coordinate system supports geoids but the geoid model is not available in the PIX4Dmatic database, enter the value of the geoid height at that location.
For more information and the list of supported geoids, please see How to use Geoids in PIX4Dmatic.
Project coordinate reference system
The project Coordinate Reference System is derived from the GCPs coordinate system. No GCPs are required to change the coordinate system in a PIX4Dmatic project.
The horizontal and vertical coordinate reference systems of the project are defined based on the imported image geolocation data or the selected GCPs coordinate reference system:
The project coordinate system is always visible on the bottom bar:- When the GCPs coordinate system is not defined, PIX4Dmatic will default the project coordinate system to the corresponding UTM zone based on the position of the image geolocation. The vertical coordinate system is set to ellipsoidal heights*.
- When GCPs coordinate system is defined, the project coordinate system corresponds to the GCPs coordinate systems. If the GCPs coordinate system is geographic the corresponding UTM zone is used for the project coordinate system.
Processing options
After setting up the project, the next step is processing it. From Calibrating the images to generating a Digital Surface Model (DSM) or an Orthomosaic, PIX4Dmatic has plenty of different options in each of the processing steps to choose from, depending on the project's needs. PIX4Dmatic comes with three different preset processing templates:
For Custom: By changing any of the processing options at any step during processing, PIX4Dmatic will automatically change the processing template to Custom.
Calibration
Calibration is the first step in processing a dataset and lays the foundation for the following steps. Default settings are provided and are generally the best place to start.
For more information: Calibration - PIX4Dmatic
For PIX4Dcatch projects: How to process PIX4Dcatch datasets - PIX4Dmatic
Dense point cloud
A dense point cloud is a series of dots spread across a volume of 3D space that represents the area of interest. The Dense point cloud step is a 3D representation of reality and it's the basis of the other 2D and 3D representations of reality that can be produced in PIX4Dmatic.
For more information: Dense point cloud - PIX4Dmatic
Planes
The Planes feature has been designed to improve mesh generation for man-made environments, including interior and urban scenes where planar surfaces are common. When added to a project, the surface of the mesh will be constrained to the associated Plane.
For more information: Planes - PIX4Dmatic
Mesh
The Mesh step is generated directly from the dense point cloud and is not necessary for every project. It is not required to generate a mesh to be able to generate the Digital Surface Model and the Orthomosaic.
For more information: Mesh - PIX4Dmatic
DSM
A Digital Surface Model (DSM) is a 2D representation of the elevation of everything in the area of
interest, both natural and artificial. The DSM step is required to generate the orthomosaic, so any
changes to the processing settings of the DSM will also impact the orthomosaic. The DSM step defines the Resolution, enables the Surface smoothing, and enables Interpolation for the Digital Surface Model (DSM) creation.
For more information: DSM - PIX4Dmatic
Orthomosaic
An Orthomosaic is a highly detailed and realistic 2D representation of reality generated by combining individual images. The Orthomosaic step is generated directly from the Digital Surface Model (DSM), so any errors or gaps in the DSM will also be present in the orthomosaic.
For more information: Orthomosaic - PIX4Dmatic
Outputs
Once processing is complete, the Exports window in PIX4Dmatic provides the selection of the following outputs:
- Quality Report
- Dense point cloud
- Point cloud from mesh
- Mesh
- Digital Surface Model (DSM)
- Orthomosaic
Locate the export folder
To access the outputs, click on File and then Open project folder. The exported outputs are in the Exports folder.
For more information: Outputs - PIX4Dmatic