July
11
2015

A simple movement AI moving to random waypoints.

In this tutorial we’ll create a schematic to move a game object to random waypoints using NavMesh. When reaching a waypoint, the game object will optionally perform an idle behaviour (using a tagged machine, e.g. wait for some time) and select a new random waypoint.

You can download the finished schematics here – if the schematic is missing the script reference after importing it into your project, just select the MakinomSchematicAsset class in the missing script field.

Download Schematic

Random Waypoint: Schematic

First we’ll create the schematic handling the random waypoint and movement. It will check if the destination was reached, start the tagged machine with the idle behaviour and move to the next random waypoint.

Open the Makinom editor, navigate to Schematics and create a new schematic. Change the following settings.

schematics_random_waypoint1

Is On NavMesh

Add > Movement > NavMesh > Is On NavMesh

This node checks if a NavMesh agent is on a NavMesh and active. If that isn’t the case, it would be useless telling the agent where to move and would result in warning messages.

Object

  • Object
    Select Machine Object.

NavMesh Remaining Distance

Add > Movement > NavMesh > NavMesh Remaining Distance

We’ll use this node to check if we’ve reached the destination (i.e. we’ll check if we’re close to it).

This node is connected to the Success slot of the Is On NavMesh node.

Object

  • Object
    Select Machine Object.

Check

  • Check Type
    Select Is Less.
  • Check Value
    Set to 0.1 (Value).

Start Tagged Machine

Add > Machine > Start Tagged Machine

We’ll use this node to start the optional idle behaviour through a tagged machine.

This node is connected to the Success slot of the NavMesh Remaining Distance node.

  • Wait
    Enable this setting.

Machine Object

  • Object
    Select Machine Object.

Starting Object

  • Object
    Select Machine Object.

Tag Settings

Click on Add Tag to add a starting tag.

  • Tag
    Set to idle.

Vector3 Multiply

Add > Value > Vector > Vector3 Multiply

We’ll use this node to create a random position within the random movement radius of the game object (stored in the local start variable radius).

Variable Settings

  • Variable Key
    Set to waypoint.
  • Variable Origin
    Select Local.
  • Operator
    Select Set.

Vector3 Value

  • Vector3 Type
    Select Random Inside Sphere.

Multiply By

  • Float Type
    Select Float Variable.
  • Variable Key
    Set to radius.
  • Variable Origin
    Select Local.

Vector3 Transform Value

Add > Value > Vector > Vector3 Transform Value

We’ll use this node to transform the random position we’ve created into world space. The random position we’ve created is around on X=0, Y=0, Z=0, so we need to translate it to the moving object.

Variable Settings

  • Variable Key
    Set to waypoint.
  • Variable Origin
    Select Local.
  • Operator
    Select Set.

Value

  • Vector3 Type
    Select Vector3 Variable.
  • Variable Key
    Set to waypoint.
  • Variable Origin
    Select Local.

Object

  • Object
    Select Machine Object.
  • Modify
    Select Transform Point.

Store Sample Position

Add > Movement > NavMesh > Store Sample Position

We’ll use this node to find the closest NavMesh position to our random waypoint.

Variable Settings

  • Variable Key
    Set to waypoint.
  • Variable Origin
    Select Local.
  • Operator
    Select Set.

Source Position

  • Vector3 Type
    Select Vector3 Variable.
  • Variable Key
    Set to waypoint.
  • Variable Origin
    Select Local.

NavMesh Destination

Add > Movement > NavMesh > NavMesh Destination

Finally, we’ll set the destination for the NavMesh agent to the new random waypoint.

Moving Object

  • Object
    Select Machine Object.

Position

  • Vector3 Type
    Select Vector3 Variable.
  • Variable Key
    Set to waypoint.
  • Variable Origin
    Select Local.

That’s it for the random waypoint schematic – click on Save Schematic and save it e.g. as RandomWaypoint.

Idle Wait: Schematic

Now, we’ll create a schematic for a simple idle behaviour – waiting for some time.

Create a new schematic and change the following settings.

schematics_idle_wait1

Wait

Add > Base > Wait

We’ll use this node to wait for some time. The wait time will be defined by the local start variable time.

  • Float Type
    Select Float Variable.
  • Variable Key
    Set to time.
  • Variable Origin
    Select Local.

And that’s it for the schematic – click on Save Schematic and save it e.g. as IdleWait.

Random Waypoint: Tick Machine

The random waypoint schematic will be added using a tick machine. The game object you want to move also needs a NavMeshAgent component.

Add a tick machine component to the game object (e.g. using the component menu: Makinom > Machines > Tick Machine) and change the following settings.

Start Settings

  • Update
    Enable this setting.

Machine Execution Settings

  • Asset Type
    Select Schematic.
  • Schematic Asset
    Select RandomWaypoint.
  • Execution Type
    Select Single.
  • Update Type
    Select Update.

Local Start Variables

  • Set Start Variables
    Enable this setting.

Click on Add Variable to add a start variable.

  • Variable Key
    Set to radius.
    Use the Value string type.
  • Type
    Select Float.
  • Operator
    Select Set.
  • Float Value
    Set to 5 (Value).

Idle Wait: Tagged Machine

We’ll add the idle behaviour using a tagged machine, started by the tag idle. By using a tagged machine for that, you can add different idle behaviour to different game objects, e.g. playing an animation or rotationt the game object.

Add a tagged machine component to the game object (e.g. using the component menu: Makinom > Machines > Tagged Machine) and change the following settings.

Start Settings

Click on Add Starting Tag to add a tag that can start this machine.

  • Starting Tag
    Set to idle.

Machine Execution Settings

  • Asset Type
    Select Schematic.
  • Schematic Asset
    Select IdleWait.
  • Execution Type
    Select Single.
  • Update Type
    Select Update.

Local Start Variables

  • Set Start Variables
    Enable this setting.

Click on Add Variable to add a start variable.

  • Variable Key
    Set to time.
    Use the Value string type.
  • Type
    Select Float.
  • Operator
    Select Set.
  • Float Value
    Select Random.
  • Value
    Set to 0.
  • Value 2
    Set to 3.

And that’s it!

Tip!

Need to stop your random waypoint AI at some point? E.g. when the game object should chase the player instead.

Use a bool object variable to do that – use it as a variable condition in the tick machine’s Condition Settings to prevent the machine from starting.