From point A, Get the location X units behind B

[pezzott1]

@WhiteTeapot

The only problem remaining is that I cannot properly explain why this works.

Get Unit Direction Vector gets the direction vector of length 1 that aims from A to B.

The scalar XUnits is offseting that vector by multiplying its value.

You then add the offsetted vector with the B wolrd location to place C.

Basical its: get direction from A to B and move X Units in that direction starting from B location.