Advanced Enemy AI

Section A (Importing)

1. Import Advanced Enemy AI .unitypackage into your project.


You should now have the AEAI menu appear under “Tools” menu. Should incase you don't find the menu, follow the following steps:


2. Open the Advanced Enemy AI folder and locate the Editor folder

3. Cut the contents of the Editor folder and place them into your root Editor folder. (if you do not have a root editor folder, create a new folder in your main assets directory and name it Editor).

4. The AEAI sub-menu should now appear on your menu bar under “Tools” menu


Section B (Setting up AI)

There are 2 ways to setup an entity to work with this AI system. We begin with the automatic way which takes no more than a few clicks.

METHOD 1 (Automatic setup)

1. Select entity or entities that you wish to add AI to in your hierarchy.

2. Open the AEAI sub menu which can be located under tools menu on your menu bar.




3. Click on “Create AI” and viola! You have successfully added AI to the selected entity/entities

Upon doing so, you will see that the objects to which AI was added are enclosed in a new GameObject named “AIEnemy”. This is now the reference to the AI and defines the shell for that entity. You may move or rename this AI entity shell, but please keep the structure of child elements as this AI system depends of it.


Adding patrol way points for AI entity:

To setup way points for a particular AI entity, start by selecting the main entity shell (titled “AIEnemy”, if name is not changed). Next go to the AEAI sub-menu that is located on your project's menu bar under tools. Now select “Add New Waypoint”. A new patrol waypoint has now been added to your AI entity's patrol route and is ready to use. This may be done as many times as needed as long as the AI entity shell is selected. NB: wayponts can only be added to AI entities and an exception will be thrown if you try to add to any GameObject that has no AI setup.


METHOD 2 (Manual Setup)

This is the manual setup method and should be followed exactly as specified here.

We will use the term AIEnemy to refer to the main shell of the AI entity. We will use the term EnemySoldier to refer to the entity to which we want to add AI.


1. Begin by dragging the gameObject to which you need to add AI onto your hierarchy. This may be your enemy fbx model for instance.




2. Next, create a new empty GameObject in your hierarchy. This is going to be the main AI entity's shell, so rename it to “AIEnemy” or something similar. We will use the name “AIEnemy” for the purposes of this example.

3. Locate the script titled “AEAIIdentifier” (located in the Main AEAI folder, under Scripts sub-folder) and add to the AIEnemy (the empty game object we created in step 1 above)

4. Locate the script titled “AIData” (located in the Main AEAI folder, under Scripts sub-folder) and add to the AIEnemy (the empty game object we created in step 1 above)





5. Next, find the script titled “EnemyAI” (located in the Main AEAI folder, under Scripts sub-folder) and add to the entity to which you want to add AI to (the EnemySoldier in this example)







6. Finally, parent the EnemySoldier GameObject to the AIEnemy GameObject by simply dragging the EnemySoldier and dropping onto the AIEnemy.


Your EnemySoldier entity now has AI added and is ready to use, but lets also create way points so the Enemy can patrol.


Adding patrol way points for AI entity:

To manually add way points, please follow the steps below:

1. Select the AIEnemy shell (as created and defined above) to which you need to add patrol way points.

2. Right click on the shell and select 3D Object, then Sphere. This creates a unity primitive sphere at the center of the AI Shell transform (This new primitive shape defines your new waypoint, and you may freely change its position and scale to suit the needs of your game)




3. Next locate the script titled “WaypointIdentifier” (located in the Main AEAI folder, under Scripts sub-folder) and add to your newly created waypoint. Adding this script is necessary if you want your waypoint to be recognized and registered by the AI system.

4. Repeat steps 1 – 3 above to add as many patrol way points as required.

NB: There is no need to disable mesh renderers or colliders for your manually created way points. The system automatically takes care of that.





Section C (Configuring AI)



Configuration of the AI parameters is done on the AIData script that is attached to the main AI shell as defined in the section above.










Below is a list of parameters contained in the script, along with descriptions of what they do.



PARAMETER

DESCRIPTION

Player

This is the Player or target gameObject that the enemy should find.



Walk Speed

Enemy speed while walking



Run Speed

Enemy speed while running



Max Patrol Wait Time

During patrol, maximum time to wait before moving to next patrol point



Max Attack Distance

Maximum distance to begin attack when player is detected



Min Attack Distance

Minimum distance to begin attack when player is detected



Enemy Behavior

Defines the enemy behavior. Patrolling way points or standing at a fixed position. Position and rotation will remain as initially set until an event occurs that requires the enemy to move or look



Random Patroller

If or not the patrolling enemy moves to way points at random



Sight Distance

Enemy can see as far as this distance



View Angle

Enemy can see as wide as this angle (in degrees)



Can Hear (Checkbox)

Enables/disables the enemy's hearing sensor



Hearing Radius

Enemy can hear as far as this distance in a circular fashion



Audibility Threshold

Enemy can hear target if it produces sound with volume equal to or greater than this value



Walk Animations

Provides slots to add walk animations for the AI entity



Run Animations

Provides slots to add run animations for the AI entity



Aim Animations

Provides slots to add aim animations for the AI entity



Shoot Animations

Provides slots to add shoot animations for the AI entity



Idle Animations

Provides slots to add idle animations for the AI entity



Death Animations

Provides slots to add death animations for the AI entity



AI Volume

Maximum volume of sounds that the AI agent produces



Gunfire Sound

The sound that the AI entity plays when shooting/Attacking



Enemy Alert Sound

The sound that the AI entity plays when it detects the player/target



Enemy Death Sound

The sound that the AI entity plays when its health reaches zero and the entity dies



Enemy Take Damage Value

Percentage of damage to take when enemy is attacked by player. Ignore if using another damage system



Player Take Damage Value

Percentage of damage to deduct from player when attacked by enemy (once for each attack strike). Ignore if using another damage system



Has Death Anim

If or not the enemy has a death animation



Death Spawn Items

Items to be spawned on enemy death.



Delay Before Destroy

Time taken before spawned items disappear



Draw Rays

If or not rays that the AI entity shoots should be shown in the editor (For debugging)



Draw Vision Cone

If or not the AI entity's cone of vision should be shown in the editor (For debugging)



Draw Hearing Radius

If or not the AI entity's circle of hearing should be shown in the editor (For debugging)



Draw Overlap Sphere

If or not the AI entity's overlap sphere should be shown in the editor (For debugging)



Switch Off Radar Distance

Turn off enemy radar when player is away by this value (save performance) if set value is less than both sight distance and hearing radius of this agent, the set value will be ignored since radar should not be off if player is within sight or hearing distance



NB: There are multiple slots for parameters such as animations. This is so that you can insert multiple clips and have the AI entity play one at random. Doing so ensures that the AI acts as random as possible every single time.









The EnemyAI Script







The “EnemyAI” script that is attached to the AI entity (the gameObject that is contained in the AI shell) is the main brain of the entire system. It contains public parameters for debugging during gameplay so that the system can be tested while in play mode. These parameters are listed below along with their descriptions





Parameter

Description

Player Is Dead

Simulates what happens if player/target is dead



Player Detected

Simulates what happens if player/target is detected by the AI entity



Patrol Reset

Restarts the AI Entity



Is Seeking

Simulates what happens if the AI entity is seeking the player/target. Usually when The AI entity hears the player/target



Current Enemy Health

The current health of the selected AI entity. This can be used in your health system to decrease enemy health, and eventually kill the enemy. Drag this to zero to simulate what happens when the AI entity dies.















The PlayerHealthManager Script





This script should be added to the player if this health system is to be used. The script contains a function called killPlayer(){}. This function gets called when the player health reaches zero and the player dies. It should be modified to suit your own game needs.