Which axis should be pointing towards the descendent bone?

[jsantell]

Currently, bones orient to face down their positive Z axis, such that positive Y is their UP, like Object3D's are in three.js. Looking at other rigging solutions, can't seem to find any good or consistent arguments for any axis other than being consistent.

[avaer]

I've been working with rigs that use Y+ (blender's convention). https://blender.stackexchange.com/questions/15609/in-which-direction-should-bone-axes-be-oriented

I haven't seen any good arguments for any convention, but it might be nice to be able to specify the convention to the lib for easier application to whatever rig convention is being used 🤔.

[mikebourbeauart]

Maya generally does X+, so there might be a need to specify convention.