comparing two Free scripted CAD systems

Werner Almesberger werner at
Sat Jul 23 20:59:21 EDT 2011

An update:

I got rid of the artefacts in OpenSCAD, which also improved render
time and mesh size.

>From the Cadmium model, I removed some constructs that were supposed
to help disambiguate some operations. What actually happened was
that Cadmium did just fine without them and rendered about 12-15
times faster.

The final score, times are in seconds:

                real    user    system  faces   vertices
OpenSCAD:         68.8    65.4     0.5  6508    3258
Cadmium:         316.3   315.9     0.3  2942    1473

It's hard to nominate a winner here. By discipline, we get:

Debug cycles: OpenSCAD (instantaneous preview, but with flaws)
Model tidiness:	Cadmium (doesn't need tweaks to avoid artefacts)
Language: a draw. Cadmium has the power of Python while OpenSCAD
  avoids some of Python's flaws. For more complex projects,
  Cadmium may come out ahead.
Rendering speed: OpenSCAD wins, although both have exhibited
  significant variations, so other models may yield different
Flexibility: OpenSCAD has extrusion, file imports, etc., while
  Cadmium has just the bare minimum needed for CSG. Both lack
  things like extrusion along an arbitrary path, automatic
  fillets or chamfers, etc.

The search for the perfect CAD isn't over yet :-)

- Werner

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