How to check if Vector is opposite to another

Hey guys,

I'm currently looking for way to negate the opposite input if my player is moving.
So I need to check if one normalized vector is opposite to another normalized vector within an angle range.
But I think a graph could better explain it:



So I need to check if my Vector 2 (the player input) is within the red range regardless in which direction Vector 1 point towards.

Has anyone a clue how to archive this?


Thank you very much

 

This is exactly what Dot Product is for
https://docs.unity3d.com/ScriptReference/Vector3.Dot.html
Passing 2 vectors returns 1 when they are pointing in the same direction, and -1 if they are opposite
https://docs.unity3d.com/Manual/UnderstandingVectorArithmetic.html (scroll down to dot product for a diagram of output values)

 

Ahhhhh thank you so much hpjohn

 

Also don't forget that a value of 0.5 is not equal to 45°, I see this done too often so I put the warning here. Basically get another placeholder vector at the threshold, and get the dot product and use that as a threshold value. I'm saying that because you can then create an interface to just tweak the place holder vector direction to fine tune the exclusion zone.