Pose space deformer - Vector Angle node, whatever it's called.

I wrote another custom node, again beholden somewhat to this post, that basically calculates the angle between to vectors.

It takes in two world space matrices and compares specified axis (x,y or z) of the nodes. It returns a ranged, 0-1, value based on user set bounds (actually the node outputs a ranged angle, full angle and dot product). Its really pretty simple but should come in handy.

I have tried to make this setup before, using Maya utility nodes and some elbow grease, but It was always quite cumbersome and I was a bit off with the math, So I thought an api node would be a better bet. So I created a nice self contained node that does it all for you and gave the user a nice display.

Here it is in action. I piped the output into the scale of the cube for visual cue of the output. 

I think i can take this a bit further, I'm thinking of trying to make this calculate a u-v space bounds of a sphere, so i can cut a more complex piece of a sphere to calculate if the vector is inside. We'll see how far i get with that!