Selling blender addons and redistribution


I’ve been working on an addon for blender ( a completely new feature ) with intent of selling it for a monthly fee.
I’ve read a bit about licenses and I need some clarification:

  1. If I make a script and sell it, the GPL license obligates me to give the source code to anyone who asks and anyone who has the source code can freely edit and redistribute it.
    Doesn’t that mean that I’m effectively out of business cuz someone can just buy my addon and then give an unlimited amount of it away to everyone for free, resulting in me losing money and control over my work?

  2. Can a patent prevent it from happening ( I checked, and my feature can be patented )?

To clarify: I have no issue with giving away the source code and someone editing it, but I don’t like the idea of someone just giving away my work for free/redistributing it without consent.

1: yes, but you are able to charge to provide sources
2: no

Can you elaborate on charging for sources? I thought I have to give the source code away for free ( unless I’m missing something ).

  1. You are effectively giving away the source code when you sell it given that it is Python. To be able to make a functioning Blender add-on you need to use the provided API which forces you to release your code as GPL. Your add-on code is still under GPL if you do not provide a license with it. It is by default.

  2. You might be able to patent an algorithm that you use in your source code to implement a feature but that is pretty much it, a GPL licensed code can’t be patented as far as I know.

They can redistribute the code without your consent. They can even resell it without your consent, but that is just a stinky behavior and I believe generally not welcomed by the community.

You can control your own brand name, logo, special artwork, models etc that might come with the add-on. For instance artworks that come with the GPL add-on may not be entitled to the same licensing as far as I know. GPL only controls the source code.

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With the patent part I meant that it counts as a “method” ( and the script itself may as well be a separate piece of software designed around utilizing that method ) and I thought this way I can somehow keep exclusive rights to distributing it.

I wonder, are there any “forks” (i.e. resales) of HardOps, or MeshMachin3, or SpeedFlow, or RetopoFlow, flying about? I haven’t seen any.

I do not think that you can patent an add-on, like I said you might be able to patent an algoritm implemented in your add-on but not the source code of your add-on.