One project that’s been on slow burn throughout this winter break has been an attempt to get a Live2D Cubism avatar animated using OpenCV facial detection routines.

Becuase Live2D provides pretty much zero useful documentation in English, I have resorted to “copying” their Windows OpenGL Demo to try to make something useful. By “copying,” I mean that I had their code up on one screen, while I took note of the structure and names and typed similarly structured and named code on another screen. Like the good citizen I am, I had the thought, “wait, could it be possible that this isn’t legal?”

Turns out it’s legal

…although not for the reasons you may think. Follow along with the Live2D Open Software License Agreement if you woul like. Keep in mind that I Am Not A Lawyer so anything I say should be taken with a grain of salt.

Restrictive things

Most of the license seems to be dedicated to preserving the license itself. Many clauses are about how, under no circumstance, can anyone come into possession of licensed code or use it without first agreeing to the license (also no re-licensing under a different license because duh). Once that’s done, the restrictions are fairly minimal: just don’t commit crimes, and also if you publish your source code that uses this open source code, Live2D can use your code too. Live2D also retains half the copyright to any modifications you make to their source code. Also you need to keep all copyright notices intact.

Things you can do

You can redistribute the code (if people agree to the license), you can publish code that is based off the license, you can make modifications (to the code, not the licensing). You also retain full ownership over the parts of Derivative Works that aren’t Live2D code. All in all, it seems to be a fairly permissive license.

Where does my copying fall under this?

I was worried that my copying might be not allowed at first glance according to section 5.1, titled No Modifications. It basically says the same thing as the title. Under certain interpretations, my “copying” might be construed as a modification (because the same result could’ve been achieved by first copying, then modifying, or really the modifications were happening on a copy in my brain, idk). The Software protected by this license includes all copies and modified copies, so the code would still be protected by the license. If it had included language like “Only Live2D is allowed to distributed the Software” then I would’ve been out of luck. Fortunately, that is not the case and I am still allowed to distribute this regardless of whether or not courts would think what I have done counts as a copy.

Code

Still very unfinished at the moment, but here it is. Pay no mind to a previous version written in Rust; it current has no Live2D components, just an OpenCV demo with a broken Windows API hook (that I plan on fixing later, then porting the Live2D logic to, can’t be a copy/modification if it’s in an entirely different language).

Also sorry for not posting recently; Winter Break has been very fun and relaxing but putting stuff on my blog has not been part of my routine. I think leaving it like this, with monthly-ish posts might be good enough. No pressure on myself, though. Maybe I’ll post about an AI thing again one day (after my PR gets accepted probably, be excited ;)).