Hello, I was searching for some books/resources to help me understand Game Engines development better to give me some boost to fix more bugs and continue documenting the Animation API, I went through 2 good books and I would like to share them (Maybe they can help with the undocumented parts):
Game Engine Architecture By Jason Gregory, this book specifically has perfect explanation for the Animation Blending, how animation clips and procedural animation work.
I only have experience in 2D framework dev, but have check on these two:
also there is russians and persian repos, which contain most new papers, but so restricted to the people out of countries.
there is a book off topic to game engine but on computer graphic with java and opengl, used in universities which can be supplementary:
[Scott Gordon](V: search on Z-Library. Scott Gordon)