Point-And-Click Movement In Unity

After setting up Unity’s Navigation system in my scene, I am implementing a point-and click movement system to work along-side my top-down camera.

Today’s Objective: Set up point-and-click movement for my top-down stealth game.

The Design:

After setting up the scene’s Navigation mesh in my previous post, Working With Unity’s Navigation System, I am now creating the player controls which allow the player to move their character around the level.

When the player clicks on the screen, I want their character to move as close to the point on screen at which the player clicked. This is achieved using a few bits of code dealing with different areas of Unity:

1. Physics.Raycast.
2. Camera.ScreenPointToRay.
3. NavMeshAgent.SetDestination.
4. Then all the Unity Navigation System’s internal pathfinding stuff.

The Implementation:

First I create a new Player GameObject and a new class called “Player Control”, then add that script as well as a NavMeshAgent component to the Player object. The character model is a child of this object and is not required for movement.

Now in the “Player Control” class, I add some variables used in the movement calculations.

Since I currently only have 2 behavior states (moving and not moving) for my character, I only need 2 Enum states to switch between.

Get the references in Start( ). Not Awake( ) because Camera.main is also a reference set in Awake, and may return null if done to early.

Now in Update( ), check if the player character is moving by checking the _agent’s velocity. If it is, set it’s state to Walking, otherwise set to Idle.

After that If-Else, check for any Player input this frame telling the character to move.

My move button is Mouse 0 (left click)

Now I create an additional method called “SetDestinationToClickPosition( )” which does what the name says.

After _agent.SetDestination is called, the NavMeshAgent component will automatically start pathfinding the Player object to the set destination. Assuming you’ve set up your Nav-mesh and obstacles correctly, it will move around any obstacles in its path.

The Result:

AI navigation is actually a really simple task when you made use of Unity’s system.