code: def separation(self, r=10):
          
          
          
          vx = vy = vz = 0
          for b in self.boids:
              if b != self:
                  if abs(self.x-b.x) < r: vx += (self.x-b.x)
                  if abs(self.y-b.y) < r: vy += (self.y-b.y)
                  if abs(self.z-b.z) < r: vz += (self.z-b.z)
                  
          return vx, vy, vz
docs: Boids keep a small distance from other boids.
          
          Ensures that boids don't collide into each other,
          in a smoothly accelerated motion.