Multishot on crossbow: spread of arrows depends on pitch

This is interesting problem. Will think about math shenanigans to solve it later.

I think it would be good if they changed the enchantment so it adds a bolt for each level of the enchantment. Make it have 5 levels and then with each level you can have greater spread.

I actually know why. I ran into this problem when creating a command thing. I think they are editing the rotation at which the calculation for arrow motion is being fired at, rather than the actual arrow motion. Let's say they are editing the arrow so it is going to the left, if you look straight down and move your mouse left, you're still looking straight down. If they actually applied a leftward motion on it (which is what I did for my commands), it would probably work properly.

Confirmed for 18w50a.

Currently, the extra arrows are fired at
yaw: φ±10°, pitch: θ;
whereas the expected direction would be something like
yaw: φ±arctan(tan(10°)/cos(θ)), pitch: arctan(sin(θ) · cos(10°) / sqrt(sin²(10°)+cos²(10°) · cos²(θ)))
(where the actual angle of the shot is yaw: φ, pitch: θ). There doesn't seem to be a simpler form.