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Convert to Points

In one sentence: Sample a solid or mesh object at a specified density to create a Points::Feature point cloud from CAD geometry.

Overview

Workbench: Points
Menu: Points → Convert to Points
Shortcut: none

Takes any geometric object — a Part solid, a PartDesign Body, or a mesh — and produces a Points::Feature by sampling points from its surfaces. A single tolerance parameter controls the maximum spacing between sampled points.

Intuition

Imagine pressing a sheet of fine mesh against a 3-D surface and marking every point where the mesh touches the surface. The maximum distance between marks is the tolerance you set. Convert to Points does exactly this, but mathematically, producing a cloud that approximates the original surface at the requested density.

This tool is the bridge from the CAD world (exact B-rep or mesh geometry) to the point cloud world (unstructured sets of coordinates). You would use it when another tool or workflow expects a point cloud as its input.

When to use it

  • You need a point cloud representation of a CAD part for comparison against a scan.
  • You want to test a point cloud processing algorithm on known geometry.
  • You are using the Reverse Engineering workbench and need a cloud to approximate back to surfaces.
  • You need to export a Part solid as a cloud (.ply, .pcd) for a downstream tool that does not accept STEP or BREP.

When NOT to use it

  • Don't use this to create a mesh — use Mesh workbench → From Part Shape if you need a triangulated mesh (STL).
  • Don't use this for scan data — if you already have a cloud from a scanner, use Import Points instead.

Step-by-step

  1. Select one or more geometric objects (Part solids, PartDesign Bodies, or mesh features) in the model tree.
  2. Choose Points → Convert to Points.
  3. A dialog appears asking for the maximum distance (tolerance in mm). Enter the desired point spacing.
  4. Click OK.
  5. FreeCAD creates one Points::Feature for each selected object, named <original name> (Points).

Tip

Start with a tolerance of 0.1 mm and adjust. For large objects, 1.0 mm is usually sufficient for visualisation. For precision comparison with a scan, match the tolerance to the scan resolution.

Parameters

Parameter Type Default Description
Maximum distance Length (mm) 0.1 Maximum spacing between adjacent sampled points. Smaller = denser cloud, longer computation.

Tolerance guide

Tolerance Cloud density Typical use
0.01 mm Very dense High-accuracy surface comparison
0.1 mm Dense General reverse-engineering reference
1.0 mm Medium Visualisation, coarse comparison
5.0 mm Sparse Quick preview only

Common mistakes and pitfalls

Very small tolerance causes out-of-memory errors

Cause: A 0.001 mm tolerance on a 100 mm × 100 mm solid can generate 10 billion points, exhausting RAM.
Fix: Start with 0.1 mm and decrease only if needed. Check your available RAM before proceeding with sub-0.01 mm tolerances.

Converted cloud has the wrong number of points

Cause: The sampling algorithm distributes points uniformly across the surface area. Highly curved or detailed regions get the same density as flat areas.
Fix: This is expected behaviour. Use Reverse Engineering tools for adaptive sampling.

Python API

import FreeCAD as App

doc = App.ActiveDocument
solid = doc.getObject("Body")   # replace with actual object name

# Convert to points with 0.1 mm tolerance
# Use the GUI command via Gui module (most reliable)
import FreeCADGui as Gui
Gui.Selection.clearSelection()
Gui.Selection.addSelection(solid)
Gui.doCommand("import Points, PointsGui")
Gui.doCommand("PointsGui.convert(App.ActiveDocument.getObject('%s'), 0.1)" % solid.Name)
doc.recompute()

See also