Spy backstab detection mechanics illustrated

Whether or not a particular knife attack is a backstab is determined by the result of three vector dot products. This video should help show visually how all of this stuff operates, even for people who don’t know what a “vector“ or “dot product“ is. In the first video segment, the yellow vector is the horizontal part of the spy’s aim direction (“SpyView“); the magenta vector is the horizontal part of the heavy’s aim direction (“VictimView“); and the cyan vector is the horizontal part of the vector pointing