> ## 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.

# Manual Feature Authoring

> Create, refine, name, and promote plane and cylinder features in Dimensioning Mode

Manual Feature Authoring gives you control over the features you measure to and from. In [Dimensioning Mode](/voyager/voyager-modes#dimensioning-mode), the **Features** toolbar button lets you author planes and cylinders by hand to complement [automatically extracted](/voyager/voyager-feature-extraction) features.

Authored features behave like automatic ones. They can be measured, used as [datums](/voyager/voyager-datums), and picked by [Flatness](/voyager/voyager-flatness), [Cylindricity](/voyager/voyager-cylindricity), and [Profile](/voyager/voyager-profile). Authoring creates **planes and cylinders**. Extraction can also return cones, fillets, and chamfers; those are not authored from this workflow. Right-click a feature for the actions that apply to it: a datum, a GD\&T check, refine, rename, or delete.

<h2 id="requirements">
  Requirements
</h2>

Manual Feature Authoring needs a Feature Set extracted with **algorithm v20 or newer**. See [Feature Extraction](/voyager/voyager-feature-extraction#algorithm-v20).

On older extractions, the authoring controls are greyed out and a tooltip explains why. Re-run Feature Extraction on the parent reconstruction to replace that Feature Set with a v20 (or newer) run, then author features on the result.

<h2 id="when-to-use">
  When to use Manual Feature Authoring
</h2>

Use authoring to complement automatic extraction — not to replace it. Typical cases:

* **Thin rims** that automatic extraction under-represents
* **Multiple disconnected components** that should belong to one plane
* **Small patches** that mimic CMM probe points
* **Small pins and threaded holes** that need a cylinder sized to the real geometry
* **Cleanup** — delete features you do not want in the scene so measurement and datum work stay focused

<h2 id="create-planes">
  Create planes
</h2>

Create planes large and small on **contiguous and non-contiguous** surfaces. Non-contiguous patches can still define a single plane, which is how thin rims and disconnected faces become measurable.

<video controls className="w-full aspect-video" src="https://mintcdn.com/lumafield/ZWRoFQpofIViz7Vs/images/mfa_plane.mp4?fit=max&auto=format&n=ZWRoFQpofIViz7Vs&q=85&s=c4006e3023d1f5b604b3736e2dfa79d2" data-path="images/mfa_plane.mp4" />

*Authoring a plane on a rim of a part.*

<Steps>
  <Step title="Open Features">
    In Dimensioning Mode, choose **Features** in the Toolbar. Confirm the Feature Set is algorithm v20 or newer.
  </Step>

  <Step title="Create a plane">
    Author a plane on the surfaces that should define it. Include disconnected patches when they belong to the same geometric plane.
  </Step>

  <Step title="Review membership">
    Confirm the highlighted surface is the plane you intend to measure or datum from.
  </Step>
</Steps>

<h2 id="create-cylinders">
  Create cylinders
</h2>

Create cylinders large and small, including small pins and threaded holes.

<video controls className="w-full aspect-video" src="https://mintcdn.com/lumafield/ZWRoFQpofIViz7Vs/images/mfa_cylinder.mp4?fit=max&auto=format&n=ZWRoFQpofIViz7Vs&q=85&s=e89c51e65b8c16f97fc29165087e6a83" data-path="images/mfa_cylinder.mp4" />

*Authoring a cylinder on geometry that had uneven edges in automatic feature extraction.*

<Steps>
  <Step title="Open Features">
    Choose **Features** in the Toolbar.
  </Step>

  <Step title="Create a cylinder">
    Author a cylinder on the pin, hole, or thread you need to measure. Size it to the region that should participate in Diameter, Cylindricity, or an Axis datum.
  </Step>

  <Step title="Review membership">
    Confirm the cylinder captures the intended surface and not neighboring geometry.
  </Step>
</Steps>

<h2 id="refine-automatic-features">
  Refine automatic features
</h2>

Right-click any automatic feature to adjust it directly. Refinement uses the same membership tools as a feature you created from scratch.

<h2 id="paint-erase-erode">
  Paint, erase, and erode
</h2>

Paint, erase, and erode give full manual control over **which surface belongs to the feature**:

* **Paint** — add surface to the feature
* **Erase** — remove surface from the feature
* **Erode** — shrink membership inward to drop noisy edges or over-extracted boundary

Use these tools after create or after right-click refine until the feature matches the geometry you will measure.

<h2 id="name-and-promote">
  Name and promote
</h2>

Right-click one feature and choose **Rename** to give it the name the drawing uses. The name can be up to 64 characters. A feature with no name is shown by its kind and number, such as Plane 3.

**Promote to sidebar** puts that feature in the **Features** group under the feature set, so the surfaces you use often stay listed. **Remove from sidebar** takes it back off the list. The feature itself is unchanged. Promotion is one feature at a time.

<h2 id="delete-features">
  Delete features
</h2>

Delete retires a feature so it is no longer offered for measurement, datums, or GD\&T. A feature that a measurement or a datum still uses cannot be deleted until that use is removed. The remaining features stay available on the volume.

<h2 id="measure-and-datum">
  Measure and datum from authored features
</h2>

Once a feature is in the Feature Set, use it like any other primitive:

* [Distance, Angle, and Diameter](/voyager/voyager-direct-dimensions)
* [Flatness](/voyager/voyager-flatness) on planes
* [Cylindricity](/voyager/voyager-cylindricity) on cylinders
* [Datums](/voyager/voyager-datums) (Plane, Axis, Midplane)
* [Profile](/voyager/voyager-profile), [Position](/voyager/voyager-position), [Perpendicularity](/voyager/voyager-perpendicularity), and [Parallelism](/voyager/voyager-parallelism), when the feature kind is one they accept

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

* [Feature Extraction](/voyager/voyager-feature-extraction)
* [3D Auto-Dimensioning](/voyager/voyager-auto-dimensioning)
* [Direct Dimensions](/voyager/voyager-direct-dimensions)
* [Flatness](/voyager/voyager-flatness)
* [Cylindricity](/voyager/voyager-cylindricity)
* [Datum Definition](/voyager/voyager-datums)
* [Profile](/voyager/voyager-profile)
* [Voyager Modes](/voyager/voyager-modes)
* [Voyager Release Notes](/platform/voyager-release-notes) and [Monthly Highlights](/platform/monthly-highlights)


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