Section: see a live cross-section of a model with a plane

Section cuts through the objects in the scene with a plane and shows the cross-section live. Use it to look inside a part, check the profile and the wall thickness, create section lines that you can process further, or cut a model in two.

Show a cross-section

1. Open a model and click Inspect › Section. The tool is also on the Mesh Edit tab and in the toolbar above the viewport.
2. Set the plane. Until you do, the panel says Clip object to get cross section. Either:
   • click Plane YZ, Plane XZ or Plane XY to place the plane across one axis;
   • click Import Plane, then click a plane object in the scene to use its position;
   • or drag a line across the model in the viewport with the left mouse button: the plane goes through this line, perpendicular to the screen.
3. Move the plane with Shift (the distance along the normal), the arrow buttons next to it, or by typing the Normal (X, Y, Z). Flip turns the plane around.

The Section Window in the corner of the viewport shows the cross-section as a flat profile. With Clip Objects on (the default), the part of the model on one side of the plane is hidden, so you see the cut in the viewport too.

Option	What it does	Default
Show Plane	Shows the section plane in the viewport.	Off
Clip Objects	Hides the part of the objects on one side of the plane.	On
Recolor Objects	Gives each object its own color, so you can tell several sectioned objects apart.	Off

Measure in the Section Window

To measure the profile, for example the wall thickness, hold Ctrl (Cmd on macOS) and click two points in the Section Window. The window shows the distance between them. Clear Distance removes the points.

Other mouse controls in the window: drag with the left mouse button to move the window, drag with the right mouse button to move the section inside it, and scroll to zoom. The Section Window settings:

• Show shows or hides the window.
• Recolored uses the object colors in the window.
• Auto Fit zooms and pans the window to the current section; Reset View does it once.

Move the plane automatically

Open Animation to sweep the plane through the model: the buttons move the plane to its lowest position, start or stop the movement, and move it to its largest position. Auto Repeat restarts the movement from the lowest position at the end. Speed is in length units per second; a negative value moves the plane backward.

Create lines from the cross-section

The section profile can become a separate object: a polyline that you can save or process on the Lines tab, for example simplify it, offset it or turn it into a mesh. See Lines and distance maps basics.

1. Open Export.
2. In Number of Sections, choose One for the current section or Many for a series of parallel sections.
3. Click Create Section Object (for One), or set Sections Step, the distance between neighbor sections, and click Create Sections with Step (for Many).

The new polyline objects appear in the Scene Tree under the sectioned object, for example Section0.

Cut objects with the plane

The Cut section splits the selected objects by the current plane:

Option	What it does	Default
Cut Objects	Cuts the selected objects by the section plane.	—
Fill Section	Closes the cut surfaces with new triangles.	Off
Keep Both Sides	Makes two objects from each original object. When it is off, only one side is kept.	On

To remove the part you do not need, select it in the Scene Tree and delete it. To cut a mesh along a geodesic or spline path instead of a plane, use Mesh Cut & Measure.