Automatic Calibration Basics

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The automatic calibration (or auto-alignment) is recommended for multi-projector setups to visually combine several projected images into a single seamless image. This technique is recommended for non-planar screens like domes or cylindrical panoramas. It can also be effectively used on planar and rectangular screens to speed up image warping and the blending process as well as to achieve more precise results in geometry and brightness.

In Screenbrerry both manual and automatic calibrations can be applied either separately or combined together.

Creating a Node Graph for Automatic Calibration

To create a node graph for automatic calibration:

  1. In the Node Graph, add a Canvas node.
  2. Add the Canvas Editor widget to your workspace and make sure that the Displays option is selected in the view mode dropdown menu.
  3. In the Canvas Editor, press the Create Display Array button. In the dialog box, enter the number of Rows and Columns to create a grid with a number of cells that matches the number of projectors* in your setup, select CalibratorPatch as the Patch Type, and press OK. As a result, a node tree is created in the Node Graph consisting of the Calibrator node connected to the CalibratorPatch nodes, each of which is connected to the Canvas node via the Display nodes.
  4. In the Node Graph, add a MediaPlayer node (or any other media source node) and connect its Image output parameter to the Source input parameter of the Calibrator node.
  5. In the Node Graph, add a Camera node, then:
    • Connect its Camera output parameter to the Camera input parameter of the Calibrator node, and
    • Connect its Image output parameter to the Camera Image input parameter of the Calibrator node.

*The number and arrangement of displays in a display array should match the settings and topology of the GPU driver settings.

Creating the Calibration Node Graph for a typical 4-projector set-up