Acting

Core

Action

An action is basically anything a character can do that may occupy it for a while.

Where the action behavior is defined depends on its use. It could be defined directly on a character so it can be triggered by AI or input(attacks, moves, …). Alternatively it may also sit on some object in the environment and become available to the character by colliding with a CharacterActionArea(Door, Levers, Dialog, …).

The most important methods to override when implementing a new action are:

CanStart returns if all requirements to start are met(key for door, stamina for move).
OnStart is called by the actor when the action is actually started so this is the main point where things are kicked of.
CanEnd defines if an action can be ended by the outside even though it has not ended itself yet.
OnEnd is called by the actor when the action is ended. This is where things are reset for reusable actions or when actions are destroyed if they are one time.
OnMessage is where messages from the character will be directed when the action is active. For example events from the animator that are needed so the action knows when it has ended.

Actor

A character actors manages a stream of actions for a character. That means taking care of how and when they are started and ended as well as forwarding the appropriate messages to them.

CharacterActorBase can technically accommodate more than one active action at a time but the most common scenario is that actions are performed one after the other rather than parallel. SerialCharacterActor serves as a good base class for these scenarios. Both the MinimalCharacterActor(ai) and BufferedCharacterActor(player) inherit from it.

Souls

Attack

Attacks in AdventureSouls have a custom implementation called SoulsAttackAction.

Attacks CanStart when the character has enough stamina and either the action has not started or when it has and it CanCombo. OnStart it triggers an animation and adds an instruction that suspends the characters regular movement so that only the root motion from the animation is used. It also removes the used stamina from the character.

It responds to the following in OnMessage
START confirms that the animation has actually started, this makes sure we are not responding to messages from the wrong animation.
DMG_ON/DMG_OFF control whether the damage on the weapon is turned on. COMBO is sent when the animation is ready to transition to the next swing.
END means the animation has ended and the action should end.

CanEnd is true when the attack CanCombo and the next action is that same attack. OnEnd the attack reset some things including the combo counter if the next action is not itself.

Roll

The roll in AdventureSouls uses an action from AdventureCore called MotionAction. This action is useful for rolls, jumps and any other moves that are based on a character animation.

CanStart returns true when is has no cost or when the character has any of the demanded resources left. OnStart removes the cost from the character and sets the animation trigger. If AlignCharacter is checked(which is the case for a roll) the motion calls AlignToInput on the characters movement. Without this the player would not be able to change direction when rolling multiple times in a row because movement is always suspended.

CanEnd is true when RELEASE has been received by OnMessage so we can transition into the next roll before it has ended. OnEnd just resets things.

Gate

The gate in AdventureSouls uses an action from AdventureCore called ObjectAction. This is a good action for interacting with objects in the world. It supports one animation on an object you’re interacting with and another(optional) one on an object that should move in the end. It is useful for doors, levers and chests.

An ObjectAction CanStart always unless there is a cost item defined the character does not have. OnStart it moves the character into place and triggers its animation. When ACT is received in OnMessage it starts the animation on the lever and in OnEnd it starts the one on the gate.

Hero

Attacks

The different directional Attacks of the Hero use a VisualScriptingAction combined with the HeroAttackAction scripting graph. The kind of attack each action performs is determined by the AttackType integer variable on the object. This integer gets sent to the animator in the graph which triggers the attack animation. During the animation the graph reacts to messages defined in the animation like DMG_ON which activates the damage sender on the sword.

Which of the attacks is started is decided in the Actions Subgraph of the HeroCharacter. This graph checks if the hero actually has a sword equipped and then selects an action based on the input direction.

Throw

Throwing is another VisualScriptingAction that shows a visual(HeroNutVisual) in the characters hand while it winds up and that instantiates a projectile(HeroNutProjectile). It is started from an equipment item(HeroNut) and uses the HeroThrow graph.

In the actual levels this item only randomly drops from pots. To try it out imediately open the HeroDebuggingGeneral scene, the inventory of the player is overridden to have it equipped.

Carry

The HeroCarryAction is s custom action either started as a context action from the CharacterActionArea(Pots) or by an Equipment Item that uses the HeroSpawnEquipment graph(Bombs). The HeroDebuggingGeneral scene contains some examples of pots, bombs and other objects that can be carried.

It parents itself to the ItemParentOverhead transform defined on the HeroPlayerCharacter when started and sets its rigidbody to IsKinematic=true. It sets the CONTEXT_ACTION_OVERRIDE variable to receive the context action button while it is active. When it is ended by Throwing, Putting or some other action occuring it unparents itself again and sets isKinematic=false so it is affected by Physics again.

Climb

In contrast to most other actions the custom HeroClimbAction starts itself under the right circumstances. It uses a GenericTriggerArea to detect climbable surfaces and checks whether the player input points against those.

During climbing it checks points in four directions to determine if the climb can continue, these points are visualized as blue spheres when the action is selected. When it cannot climb upwards is performs Raycasts forward and down to check if the character can pull itself up. These are visualized as green lines.

To define a surface as climbable simply add a GenericTriggerItem and set the Key to CLIMB. Check out the HeroDebuggingClimbing scene for examples of climbable surfaces.

Block

The HeroBlockAction lets characters pull and push on rigidbodies. It is defined on the respective side of the objects that needs to be pushed and gets started through the CharacterActionArea.

The rigidbody needs to be set to isKinematic=true when not used so the character can’t simple push it away by running against it. When pushed isKinematic is set to false to allow the object to fall when it is pushed over a ledge. The action then ends itself and waits for the rigidbody to stand still before it resets isKinematic.

The HeroDebuggingBlock scene contains various examples on how block pushing may be used.