Version: 2017.2
public static Quaternion LookRotation (Vector3 forward, Vector3 upwards= Vector3.up);

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.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour { public Transform target; void Update() { Vector3 relativePos = target.position - transform.position; Quaternion rotation = Quaternion.LookRotation(relativePos); transform.rotation = rotation; } }

See Also: SetLookRotation.