Extrusion Body makes a mesh by moving one line, the profile, along a straight axis or along another line, the trajectory. Use it to turn a section contour into a prism, or to sweep a profile along a path: a rib, a channel, a strip. For a round tube of constant radius around a line, Offset is simpler.
Profile and Trajectory
- The profile is the lines object you select before you open the tool. A closed profile gives a body with open ends, which Fill Holes can close; an open profile gives a strip.
- The trajectory is either the X, Y or Z axis of the scene with a length you set, or another lines object of the scene (Use Custom Trajectory). The custom option is unavailable when the scene has no other lines object; its tooltip then says No other lines objects in the scene.
Make an Extrusion
- Select the profile in the Scene tree.
- Click Lines › Extrusion Body.
- Choose the direction: Move Along Y Axis, Move Along X Axis, Move Along Z Axis, or Use Custom Trajectory and pick the line in Trajectory.
- Set the options and click Apply.
| Parameter | What it does | Default |
|---|---|---|
| Trajectory Length | Axis modes only: how far the profile moves along the axis (0.001–1000) | 1 |
| Allow Rotation | Custom trajectory only: turns the profile at the trajectory's vertices so it follows the bends. Off: the profile only moves | On |
| Auto Body's Center | On: the center of the profile's bounding box moves along the trajectory. Off: the origin of the profile's own coordinate system does | Off |
| Start Mesh from Source | The profile lies exactly on the resulting mesh | On |
| Fill Holes | Fills the flat holes at both ends of the body | Off |
Result
The tool makes a new mesh and closes. Its name is the profile's name with _xextrusion, _yextrusion or _zextrusion added, or with the trajectory's name and _extrusion for a custom trajectory. The profile stays in the scene.
In the example, a section of a CAD housing made with Section was extruded 40 mm along Z with Fill Holes on. The result is a closed mesh: the Information panel shows its Volume.
To sweep along a smooth path, make the trajectory with To Spline first.
