Angle

This labeling tool is only available to use in the 3D Medical Labeling Editor (e.g. on NIfTI/NRRD files).

The Angle labeling tool allows you to draw and measure angles in 3D medical assets.

How to add an Angle tool to your project

From the project’s Settings tab, enter the Category Schema section.

Click on Add Category. From the list that appears, click on Angle.

A new row will appear named Angle. Click on it to expand it.

Schema ID: A unique ID which identifies this class in your project.

Title: The name of your class.

Required: Whether or not annotators have to add at least one instance of this class in order to submit their annotation task.

If you would like to ask labelers further questions, for example, if you want to show a further radio after drawing the annotation, click on Add Classification and add a further question. More on nested questions here.

How to Draw an Angle

Click on the image where you’d like the angle vertex to be. Then, click on it or on its edge nodes to change its angle or where it is located.

Example Export

This is what the Angle tool output looks like in the final export. See its section on our documentation page on our export for more.

[
  {
    "asset": "https://angohub-test-assets.s3.eu-central-1.amazonaws.com/67ed4234d51cdf151a019b3e/assets/72579265-072d-4a8e-893f-1fd3225fd80c.nii.gz?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA3FV7TSYIZFWAQDUV%2F20250902%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Date=20250902T112709Z&X-Amz-Expires=86400&X-Amz-Signature=3d6ee78dce799adc3f2eae6e1d77f0251bf27d63df24f7a54363f308d890d2df&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject",
    "assetId": "67ed4269cce65e74f1a24a0d",
    "externalId": "medical-compressed-nifti.nii.gz",
    "batches": [],
    "task": {
      "taskId": "67ed4269cce65e74f1a24a1f",
      "type": "default",
      "stage": "Complete",
      "stageId": "Complete",
      "updatedAt": "2025-09-02T11:25:46.054Z",
      "updatedBy": "[email protected]",
      "totalDuration": 0,
      "tools": [
        {
          "angle": {
            "vertex": [
              121,
              112,
              60
            ],
            "p1": [
              17,
              166,
              60
            ],
            "p2": [
              170,
              176,
              60
            ],
            "angle": 100
          },
          "objectId": "5b1e9542a735f72f5edc815",
          "classifications": [],
          "schemaId": "e83ed8591f14d6c804f9919",
          "title": "Angle Tool"
        }
      ],
      "classifications": [],
      "relations": [],
      "brushDataUrl": null,
      "medicalBrushDataUrl": null
    }
  }
]