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Clip

The Clip tool trims surfaces using clipping planes and other geometric tools, with the option to create closed (capped) surfaces at the clip boundary. This is particularly useful for creating cross-sectional views, preparing surfaces for 3D printing, or trimming surfaces at precise locations.

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​

Clipping provides a clean, planar cut through surfaces. Unlike the Cut tool which uses arbitrary ROI shapes, the Clip tool excels at creating geometrically precise cuts—especially when you need the resulting surface to remain watertight with a properly capped boundary.

The tool offers various plane orientations and interactive positioning, making it easy to clip surfaces at any angle or location.

Interface​

Clipping Tools​

Position the clipping plane using interactive handles in the 3D view. The plane can be:

  • Translated along its normal direction
  • Rotated to any orientation
  • Aligned to specific anatomical planes (axial, sagittal, coronal)

Clip Options​

OptionDescriptionDefault
Closed clipCreate a cap over the clipped region, closing the surfaceDisabled
InvertClip the outside region instead of the inside regionDisabled
Retain clipped regionSave the removed portion as a new surface objectDisabled

Parameters​

Closed Clip​

When enabled, a new triangulated surface is created to cap the cut boundary, resulting in a watertight surface. This is essential for:

  • 3D printing preparation
  • Volume calculations
  • Boolean operations
Requirements

The Closed clip option requires the input surfaces to be closed and manifold. If your surface has holes or non-manifold geometry, fix these issues first using Diagnostics and Fixes.

Invert​

Controls which side of the clipping plane is removed:

  • Unchecked: Remove the portion on the default side (typically inside/below)
  • Checked: Remove the opposite portion (typically outside/above)

The preview in the 3D view updates to show which portion will be retained.

Retain Clipped Region​

When enabled, the removed portion is not discarded but instead saved as a new surface object. This effectively splits the surface into two parts along the clipping plane.

Actions​

ButtonDescription
ResetReset the clipping plane to the bounding box center of selected surfaces
ApplyExecute the clipping operation

Clip vs. Cut​

FeatureClipCut
Planar cuts✓Limited
Freehand shapes✓
3D primitive shapes✓
Closed (capped) surfaces✓
Interactive plane positioning✓
Best for cross-sections✓
Best for irregular regions✓

Typical Workflows​

Creating a Cross-Section​

To create a clean cross-sectional cut:

  1. Open the Clip tool
  2. Position the clipping plane at the desired location
  3. Enable Closed clip for a watertight result
  4. Use Invert to toggle which half to keep
  5. Click Apply

Splitting a Surface in Two​

To divide a surface into two parts:

  1. Position the clipping plane at the split location
  2. Enable Closed clip (optional, for watertight halves)
  3. Enable Retain clipped region
  4. Click Apply

Both halves are preserved as separate surface objects.

Preparing for 3D Printing​

To create a flat base for 3D printing:

  1. Position the clipping plane parallel to the desired base
  2. Enable Closed clip to create a solid, printable surface
  3. Adjust Invert to keep the correct portion
  4. Click Apply
  5. Verify the result is manifold using Diagnostics and Fixes

Creating an Anatomical View​

To expose internal anatomy:

  1. Position the clipping plane at the desired viewing angle
  2. Leave Closed clip disabled to see inside the structure
  3. Click Apply

The open cut allows visualization of internal features.

Plane Positioning​

Interactive Handles​

The clipping plane widget provides interactive controls:

HandleAction
Center sphereTranslate the plane in 3D space
Normal arrowTranslate along the plane normal
Rotation ringsRotate the plane around its axes
Edge handlesResize the plane visualization

Preset Orientations​

Quick-set buttons (if available) align the plane to:

OrientationDescription
AxialHorizontal plane (XY plane)
SagittalLeft-right dividing plane (YZ plane)
CoronalFront-back dividing plane (XZ plane)

Best Practices​

  1. Use Closed clip for watertight results: If you need the clipped surface for 3D printing, simulation, or Boolean operations, always enable Closed clip.

  2. Check manifoldness first: Closed clipping requires manifold input. Run diagnostics before clipping.

  3. Preview before applying: The 3D view shows which portion will be retained. Verify this is correct before clicking Apply.

  4. Use Retain for both halves: If you need both portions of the split surface, enable Retain clipped region.

  5. Reset for alignment: Use Reset to center the clipping plane on your surface, then fine-tune from there.

  6. Combine with other tools: After clipping, you may need to use Fill Holes or Smooth to refine the result.

See Also​