[NMS] Check if custom entity is looking directly (Or a little off) at a player

Hello! I've got a zombie, and his AI is perfect except for one thing: He will target you no matter where you are relative to him. Walls are the only exception. Can you point me in the right direction on how to accomplish what I need? All I need is a custom PathfinderGoal (Or other) to check if the entity is staring in a player's general direction.

 

This can be done by using the dot product of Vectors. You need two vectors: one is the direction Vector from the entity that we want to check, and the other one is the Vector from that entity to the entity it's supposed to be looking at. Normalize both Vectors and take the dot product: this will give you a value between -1 and 1. The closer it's to 1, the 'more directly' is the entity looking at the other entity.

Code:

function isTargeting(Entity entity, Entity other)
{
    // The first Vector
    Vector dir = entity.getDirection();
    // The second Vector
    Vector towards = other.getLocation().subtract(entity.getLocation());
    // Then normalize both, and take the dot product between both
    double dot = dir.normalize().dot(towards.normalize());
    // 0.75 is just an assumed number. The closer to 1, the more precise your check will be
    return dot > 0.75;
}

 

fireblast709 Thank you! I'll try it out, and get back to you on its results.