How to make a spotlight look at the mouse

So I have a spotlight but I need it to stay in one place - on the ground.Whilst the beam (the end) needs to follow and point at the mouse. I have absolutely no idea how to do this. So the beam kind of needs to rotate around an anchor at it's source.

All I can find is how to make the light follow the mouse at its source. Rather than just the beam facing the mouse.

Any help is greatly appreciated.

 

First, you need to transform the mouse cursor position from the 2D viewport into the 3D world of your game. Change the z value to the distance from the camera to your spotlight (default would be 10, because games almost always happen at 0 and the camera is at -10): http://docs.unity3d.com/ScriptReference/Camera.ViewportToWorldPoint.html
Then, have your spotlight look at it: http://docs.unity3d.com/ScriptReference/Transform.LookAt.html

 

I would use ScreenPointToRay, not ViewportToWorldPoint. then simply get the point out that you need.

Code (csharp):

1.  
2. point = Camera.main.ScreenPointToRay(Input.mousePosition).GetPoint(10);
3.  

Also, it depends on the direction that you are taking. You could use the Ray given in ScreenPointToRay as part of a Raycast. Thus getting the point on the colliders that the mouse hits.