Quaternion.LookRotation
static function LookRotation(forward: Vector3, upwards: Vector3 = Vector3.up): Quaternion;
Parameters

forward The direction to look in.
upwards The vector that defines in which direction up is.
Description

Creates a rotation with the specified forward and upwards directions.

Returns the computed quaternion. If used to orient a Transform, the Z axis will be aligned with forward and the Y axis with upwards if these vectors are orthogonal. Logs an error if the forward direction is zero.
	// Most of the time you can use:
	// transform.LookAt instead

var target : Transform; function Update () { var relativePos = target.position - transform.position; var rotation = Quaternion.LookRotation(relativePos); transform.rotation = rotation; }
See Also: SetLookRotation.