I remembered a great book I read years ago called Developing Games in Java by David Brackeen.
In it he actually develops a 3D game using pure Java drawn on canvas - and it performs amazingly well!
You can get the code here:
I wish someone would pick up on this to make a library out of it. Even if this doesn’t do everything the ability to do basic 3D without any dependencies would be amazing.
I would do it but I don’t understand the math. But I’m willing to assist in any way if anyone picks up this idea.