So say that I use LeoCAD to export some brick models to Blender. Would it be unethical to modify the models in various ways (tris to quads tool, subsurfacing, textures, rigging, etc.) and then publish them to the internet, assuming that I do not try to profit from them in any way?

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    Ethics is always a personal taste and choice, isn't it? Commented Mar 17, 2012 at 14:20
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    @abatishchev Not really - there are legal agreements covering the parts, so they should be followed - as some of these allow for derivative and commercial use, there are no real ethics involved. The LDraw Steering Committee ask for donations of time or money if you are profiting from the library, which is where "ethics" might come in to play. Personally if someone wants to convert all these files into a more "native" format for use in traditional modelling apps I'm sure people would be very grateful. Commented Mar 17, 2012 at 22:55
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    In this case it's better to say "legal", not ethic, imo. Commented Mar 18, 2012 at 15:24

1 Answer 1


Almost certainly no, but with some caveats:

The LeoCAD parts library is based on the LDraw parts library, which has a Legal Agreement here.

The vast majority (and I would assume the entire subset used by LeoCAD) are covered under the Creative Commons Attribution License 2.0:

You are free:

  • to Share — to copy, distribute and transmit the work
  • to Remix — to adapt the work
  • to make commercial use of the work

Under the following conditions:

  • Attribution — You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the works).

However there are parts in the library that are not covered by the LDraw Contributor Agreement (CA), and these are covered by the more restrictive NonCA agreement. You are expressly forbidden from sharing, or making derivative works of these parts (creating 2d renderings of the elements isn't considered a derivative work, but converting the parts to a different format is).

All part files should have a license comment in their header stating either:

0 !LICENSE Redistributable under CCAL version 2.0 : see CAreadme.txt


0 !LICENCE Not redistributable : see NonCAreadme.txt

You should check those parts you wish to adapt, and proceed accordingly.

  • How do I tell which parts are under which licenses?
    – fouric
    Commented Mar 18, 2012 at 0:14
  • The .ldr or .dat files are text based, do you can open them and check the comment lines at the top. I've not checked but I'd assume that all the ones included in LeoCAD were the ones covered by the CC BY license. Commented Mar 18, 2012 at 9:59
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    Note that the LDraw community has been actively working to remove non-CA parts, and there are only 5 left in the latest release. Not sure how up-to-date the LeoCAD parts library is, though.
    – Joubarc
    Commented Mar 18, 2012 at 10:23
  • Somewhat out of date last time I looked ;) Commented Mar 18, 2012 at 12:04
  • Are 2d renderings of the CC-BY parts considered to be derivative works? Is attribution required for those 2d renderings? Commented Mar 18, 2012 at 15:00

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