Cut

The Cut tool allows you to remove or extract portions of visible surface(s) using a variety of region-of-interest (ROI) selection methods. This is essential for trimming unwanted parts of a surface, isolating specific regions, or preparing surfaces for further processing.

Medical Disclaimer

This tool is provided for research and educational purposes only. Any clinical or diagnostic use requires proper validation in accordance with applicable regulations.

Overview

The Cut tool operates on all visible surfaces, making it easy to trim multiple objects simultaneously with a single operation. You define the region to affect using ROI tools, then choose whether to remove that region or extract it as a new surface.

Unlike the Clip tool which uses infinite planes, the Cut tool offers more flexible ROI shapes including freehand drawing, geometric primitives, and 3D selection regions.

Interface

Operation

Select what happens to the selected region:

Operation	Description
Cut	Remove the selected ROI portion from the visible surface(s)
Retain	Remove the selected portion and create a new surface object from it

ROIs mode

Choose the category of ROI selection tools. The mode also decides how the operation is triggered:

Mode	Tools	Applied
Quick	Drawn directly in a view	As soon as the ROI is completed
Advanced	Interactive 3D shapes with numeric parameters	With the Apply button
Primitives	A managed list of named ROI primitives	With the Apply button

Quick mode tools

The ROI selection tools group holds six buttons. Each ROI is drawn directly in the 3D view, and the cut runs as soon as the ROI is finished, so this mode has no Apply button. Hold the Alt key while drawing to spin the camera.

Tool	How to draw it
Rectangle	Left-click and drag, then release to apply
Polygon	Left-click to place vertices, then press and release the middle mouse button to close the polygon and apply
Sphere	Left-click and drag to draw a sphere around the target area
Plane	Left-click and drag to define a cutting plane
Cylinder	Left-click and drag to define a cylinder through the target area
Lasso	Left-click and drag to draw a freehand outline, then release to apply

Advanced mode tools

Advanced mode places one interactive shape in the 3D view and exposes its exact parameters, so a cut can be positioned numerically and reproduced later.

Tool	Parameters
Cuboid	Position (mm), Size (mm), Rotation (°), and Show box
Sphere	Center (mm), Radius (mm), and Show sphere
Cylinder	Center (mm), Radius (mm), Axis:, Adjust cylinder along X/Y/Z-axis, and Show cylinder
Plane	Origin (mm), Normal:, Adjust plane normal to X/Y/Z-axis, and Show plane

Primitives mode

Primitives mode uses a table of named ROI primitives, built with the same shapes and the same controls as the Primitives tool. Add the ROIs you need, show the ones that should take part, and click Apply to cut with all visible ROI primitives at once.

The table toolbar offers Add a new ROI., Delete the selected ROI(s)., Delete all ROIs., move up and down, Import ROIs from the disk., and Save ROIs to the disk., so a set of inspection ROIs can be reused across projects.

Actions

Button	Description	Available in
Reset	Reset the ROI placement to the bounding box of the visible surfaces	Advanced mode
Apply	Execute the cut operation	Advanced and Primitives modes

Cut vs. Clip vs. Editor

Understanding when to use each cutting tool:

Scenario	Cut	Clip	Editor
Trim using freehand shapes	✓
Trim using infinite planes		✓
Trim using 3D primitive shapes	✓
Create closed (capped) cuts		✓
Delete individual triangles			✓
Extract region as new surface	✓	✓	✓
Apply to multiple surfaces at once	✓	✓	✓

Typical Workflows

Trimming Excess Geometry

To remove an unwanted portion of a surface:

1. Make only the surfaces you want to cut visible
2. Open the Cut tool
3. Select the Cut operation
4. Select Quick mode and a drawing tool
5. Draw the region to remove in a view. The cut runs as soon as the ROI is completed

Extracting a Region

To isolate a specific portion as a new surface:

1. Open the Cut tool
2. Select the Retain operation
3. Define the region to extract with any ROI mode
4. In Advanced or Primitives mode, click Apply

The selected region is removed from the original surface and added as a new surface object.

Trimming with a 3D Box

To remove everything inside a box region:

1. Select Advanced mode and the Cuboid ROI selection tool
2. Enable Show box, then click Reset to fit the box to the visible surfaces
3. Drag the handles in the 3D view, or type exact Position (mm), Size (mm), and Rotation (°) values
4. Select Cut to remove the enclosed portion or Retain to extract it
5. Click Apply

Precise Cutting with Polygons

For precise cuts along specific boundaries:

1. Select Quick mode
2. Choose the Polygon tool
3. Left-click to place vertices along the desired cutting boundary
4. Middle-click to close the polygon. The cut is applied immediately

Best Practices

1. Hide unaffected surfaces: The Cut tool operates on all visible surfaces. Hide surfaces you don't want to modify.

2. Use Retain for safety: If you're unsure about the cut, use Retain to preserve the removed portion as a new surface.

3. Reset in Advanced mode: Use the Reset button to initialize the interactive shape to the bounding box of your surfaces, which is a good starting point for adjustments.

4. Consider closed clipping: If you need the cut surface to remain watertight, use the Clip tool with the Closed clip option instead.

5. Fill holes after cutting: Cutting creates open boundaries. Use Fill Holes if you need a closed surface.

6. Use appropriate mode:

   • Quick for fast, freehand cuts drawn straight in a view
   • Advanced for a numerically defined, reproducible 3D region
   • Primitives for cutting with several saved ROI shapes at once

Mouse Interaction

Interaction	Action
Left-click and drag	Draw a Rectangle, Sphere, Plane, Cylinder, or Lasso ROI, then release to apply
Left-click	Place a Polygon vertex
Middle-click	Close the polygon and apply
Alt (hold)	Spin the camera while an ROI tool is active

See Also

• Clip - Trim surfaces using infinite planes with optional capping
• Editor - Manual triangle-level editing
• Fill Holes - Close holes created by cutting
• Boolean - Compute geometric Boolean operations