> ## Documentation Index
> Fetch the complete documentation index at: https://support.lumafield.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Unroll

> Flatten a cylindrical section of a scan into a 2D image

Unroll unwraps a cylindrical part into a flat image so you can inspect the whole circumference in one view. Use it for the inside wall of a tube, a bore, or a thread. The result is a 2D image you can review the same way as any other image plane.

[Stack Aggregation](/voyager/voyager-stack-aggregation) is the other 2D thickness tool. A slab keeps the slices stacked in the volume. Unroll cuts a ring out of the volume and lays that ring flat.

Unroll is in the Toolbar in [Analysis Mode](/voyager/voyager-modes#analysis-mode).

<h2 id="what-you-are-defining">
  What you are defining
</h2>

The workflow builds a cylinder and then samples a wall around it.

* **Cylinder axis** is the direction the part runs. You choose it on the setup step.
* **Circle** is the trace of that cylinder on the slice. Three clicks on the edge set it. Center and radius can be edited afterward.
* **Annulus thickness** is how far the sample extends across the wall, through the traced circle. The inner edge cannot pass the axis.
* **Output pixel size** is the resolution of the flat image, in millimeters. It cannot be finer than the volume's voxel size.
* **Aggregation** collapses the thickness into each output pixel: **Mean**, **Minimum**, or **Maximum**. If the annulus is thinner than half an output pixel, each pixel takes one sample and the aggregation choice does not change the image.

A preview of the unrolled image sits beside the slice while you edit. Submit runs the unroll on the cloud. A notification tells you when the image is ready.

<h2 id="workflow">
  Workflow
</h2>

<Steps>
  <Step title="Open Unroll">
    Choose **Unroll** from the Toolbar and select the volume.
  </Step>

  <Step title="Choose the cylinder axis">
    Set **Cylinder axis** to the direction the bore or thread runs.
  </Step>

  <Step title="Trace the edge">
    Click three points on the edge of the cylinder in the slice. Press **Escape** to start over, or **Redraw circle** after the trace is set.
  </Step>

  <Step title="Set the wall">
    Adjust **Center**, **Radius**, and **Annulus thickness**. The circle's edges are drawn in the Viewport.
  </Step>

  <Step title="Choose the output">
    Set **Aggregation** and **Output pixel size**. The panel estimates width, height, samples across the thickness, and file size before you submit.
  </Step>

  <Step title="Submit">
    Submit the workflow. The unrolled image is added to the Project when processing finishes.
  </Step>
</Steps>

<Tip>
  Trace the edge you actually want to inspect. For an internal thread, trace the crest or root you care about, then set the annulus thick enough to cover the thread depth. A radius that sits in air produces an empty image.
</Tip>

<h2 id="related-pages">
  Related pages
</h2>

* [Stack Aggregation](/voyager/voyager-stack-aggregation)
* [2D Inspection](/voyager/voyager-2d-inspection)
* [Inspection Planes](/voyager/voyager-inspection-planes)
* [Voyager Modes](/voyager/voyager-modes)
* [Voyager Release Notes](/platform/voyager-release-notes)


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