The issue here is not retopology in itself, but the fact that the modder states it is his original work.
It would the same issue for an imported model under CC BY for example.
But it would be perfectly ok to "retopo" that same CC BY model, when the original author's name is provided.
In short : retopology can't be claimed an original work, a license must be provided as for the other imports.
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Am sorry that I can't find any BY SA mod with forbidden derivatives. I feel confused, I wouldn't write such an assertion only to bother people. I must have been mistaken, or idk what happened.
In the same idea of consistency, I would disallow licenses which have a NC and/or a ND equivalent clause.
disallow ND (no derivative) because of the removed wheels problem I wrote in my previous post, unless the modder keeps the wheels and sets an invisible material... but almost all imported models need some fixes, stitches, up axis rotation, etc, wich modify the original mesh, and thus breach the no derivative clause. It is impossible to handle geometry checks in the long run.
disallow NC (no commercial use) because a LFS mod is used in the commercial context of LFS, wich is a business that hosts and sells access to download the mods for use in the sim, and displays some ads from IRL companies (bmw...). (authorization from author is needed for commercial use)
It is a bit of a pity that this mod import story turns into a witch hunt :
- you are not legally required to check the validity of the licenses. You act with good faith when you simply trust the provided source license.
You can't be responsible of being misled by the uploaders/hosts. At worst you will be asked to remove the mod if infrigement is proven. No big deal.
- most people making mods are only expressing their passion, I doubt there is any intent to bypass the copyright rules, or make the reviewers work hard(er). People just don't know how copyrights work, they are creative and excited and try alternate ways to make mods faster, without documenting and learning about copyrights mechanics. They are not working against LFS, but FOR LFS. That's what I see and read online. Dont misunderstand.
Why not witch hunt pirate photoshop/3ds max/ users ? and the same copyright tracking on textures and blueprints ? that would be much more consistent.
A last thought about importing parts of copyrighted materials. In the case of music (hiphop and rap are great examples), it ok to sample, or "extract a quote" of copyrighted materials.
It should be same for mods : creating a whole mod from many parts of copyrighted works should be acceptable.
In the end, why not make it all simpler and just relax the witch hunt ? We will never be able to handle the copyright checks in the long run. If it was possible, the copyright issues on uploaded models in 3D meshes databases would be already insignificant; because stolen source material wouldn't be so much abundant for download in the first place : they would be easily filtered out by the repository website.