Getting started
      Back to home
      1. Pix4D Documentation
      2. PIX4Dcatch
      3. Getting started

      Capture a project - PIX4Dcatch

       

      IN THIS ARTICLE

      Capture a project

      Information: There are different ways to georeference the images:
      • Standard georeferencing with meter level of accuracy using the integrated (phone) GNSS/GPS sensor.
      • RTK georeferencing with a supported RTK Device for centimeter-level accuracy. For more information: How to use PIX4Dcatch a supported RTK device.

      PIX4Dcatch viDoc RTK bluetooth dialog

      Capture a project

      Before you start capturing, it is recommended to plan a capture route for best results. Determine an optimal direction to take. Depending on the subject matter and size, circular and/or linear capture paths can be followed. For larger subjects, the use of multiple parallel paths (horizontal or vertical) can be considered with adequate overlap between paths.

      Illustration showing better practices when capturing

       

      1. Tap the record button record button and slowly move the device to start capturing. The app will automatically start capturing images based on the selected settings.
      2. If necessary, tap the pause button pause button to pause the recording. Tap the record button record button to start recording again.
        Important: Use the pause button only when necessary, and return close to where the pause was initiated.
      3. iOS and Android users who have LiDAR or ToF sensors in their devices can use the Live Preview feature to gain insight into what is being captured.

         

         

      4. After the capture is complete, tap save button to save the captured project. The cancel button cancel button can be used to abort a project while capturing.
      5. After tapping the save button button, a capture report will be displayed for reviewing the overall project quality. The following information is displayed:
        • Project Name.
        • Images Image icon - Number of images taken for the capture.
        • center button Tap to center the project.
        • layer button Tap to access:
          • cameras button Toggle the camera positions visibility.
          • pointcloud button Toggle Sparse point cloud. Available for devices with a TOF and/or LiDAR sensor. Tie points will be displayed for devices without these sensors.
          • close button Close the menu.

        PIX4Dcatch RTK quality report

      6. After tapping Save, the project is created and stored on the device.
      Tips:
      • Fill the image frame with the content you wish to reconstruct.
        • Employ a slight downward tilt.
        • Point the camera to capture near and far.
        • Avoid moving objects including the shadow of the operator.
        • Capture rich textures in good lighting.
      • Move and turn Slowly.
        • Do not change the orientation of the camera while standing still. e.g. turn in place.
        • Avoid any sudden perspective changes / rapid or waving motions.
        • Try to maintain a consistent distance between the camera and what it captures.
        • Plan for smooth transitions around corners.
        • It is better to raise or lower the camera height when trying to capture further detail in higher or lower regions than it is to point the camera up/down from the same height.
      • Plan.
        • Identify areas that may have limited visibility due to scene geometry.
        • Plan the image collection with consideration to lighting.
        • Consider potential locations for manual tie points and ground control points. Distribute accordingly.
        • In difficult terrain, a practice run can help.
      • Try to avoid.
        • Low light scenes, if you need to scan a scene with poor lighting try to move slowly or use artificial light avoiding shadows. 
        • Pointing the camera in the exact direction of travel/ahead.
          • Face the camera at an angle from the direction of travel.
        • Try not to travel back exactly over the same path.
          • Change the elevation and path slightly, whenever necessary to double over a previously captured region.
      • Ensure stable internet.
        • Use WiFi only if the scene has full coverage and the connection is stable.
        • Turning WiFi off is a good idea, as WiFi may shadow mobile data (4G) connection, even if it has a weak signal. Projects with mixed WiFi and mobile connection may fail.

      With the project saved, it can be uploaded for processing or the device is ready to start a new project.

      Tip: To use automatic Tag Detection during capturing, please import the Point Collection before capturing. For more information: How to use automatic Tag Detection and manual GCP marking - PIX4Dcatch RTK

      Processing a PIX4Dcatch project for more information on how to process.

      How to export PIX4Dcatch projects (iOS/Android) for more information on how to export your project to save or process locally.