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Hull

In one sentence: Compute the convex hull of all selected objects using OpenSCAD's CGAL engine, producing the smallest convex solid that contains every input shape.

Overview

Workbench: OpenSCAD
Menu: OpenSCAD → Hull
Requires: OpenSCAD binary installed
Shortcut: none

Passes all selected objects to OpenSCAD as a hull() call and imports the result as a Part object. All input objects are hidden. The convex hull is the tightest convex bounding solid around all the inputs.

Intuition

Wrap a rubber band around several objects lying on a table — the shape the rubber band makes is the 2-D convex hull. Hull does the same thing in 3-D: it finds the smallest convex solid that contains all the selected objects. No concavities, no overhangs — just the outer convex skin.

When to use it

  • You need a convex bounding solid for interference or clearance checking.
  • You want to create a convex approximation of a complex shape for simulation.
  • You are using the Hull-then-Minkowski pattern to create rounded offset shapes.

When NOT to use it

  • Without OpenSCAD installed — requires the OpenSCAD binary.
  • When you need non-convex bounds — use Part workbench bounding box tools.

Step-by-step

  1. Select two or more objects.
  2. Choose OpenSCAD → Hull.
  3. FreeCAD hides the inputs and creates a Part object containing the hull.

Python API

import FreeCADGui as Gui
Gui.doCommand("Gui.runCommand('OpenSCAD_Hull', 0)")

See also