Quaternion.LookRotation on only one axis?

Questions & Answers
1

Quaternion look = Quaternion.LookRotation(player.position - transform.position);
transform.rotation = Quaternion.Euler(look.eulerAngles.x, 0, 0);

I simply want my object to look at the player object only on the X axis. Try the script out yourself. Once it gets to 90 degrees it stops trying to look towards the player object.

2

Easiest way I can think of is to bring the target point to the level of the transform on y and z.
I haven’t tested it so does this do any good?

Vector3 target = new Vector3(player.position.x, transform.position.y, transform.position.z);
transform.rotation = Quaternion.LookRotation(target - transform.position);