Interaction

How to Pew, Pew, Pew!

The two previous chapters we overviewed how to create a Weapon and an Ammo object, as well as see what each option does. In this chapter we'll see how to put everything together and make Characters make use of the Weapon and Ammo objects in order to pull, aim and shoot at stuff.

Character Shooter

The Character Shooter component is a special component that must be added to each Character that is going to hold a weapon.

If this component is not detected, Game Creator will automatically add it for your, but it's better if you add it yourself in the editor, or you'll miss some features, such as saving the amount of ammunition.

The Player should use another component called Player Shooter instead. This will allow it to use different aiming modes, unavailable to NPCs.

Drawing & Holstering Weapons

Drawing and holstering weapons is done using the Weapon Draw and Weapon Holster Actions. These automatically equip the character with the specified weapon.

The Ammo field is optional and, if none is specified, it will use the default Ammo object defined by the Weapon.

Aiming

Aiming is the process of choosing a target at which to shoot at. There are multiple aiming types, each addressing requirements set by different types of games. Here is the full list of options available when using the Aim Weapon Action.

• Stop Aiming: Used to stop aiming with the weapon. Typically used when releasing the aiming button.

• Aim Camera Direction: Aims where the camera looks at. Perfect for Third-Person and First-Person shooter games.

• Aim at Target: The target is specified by a Transform object and keeps track of its position.

• Aim at Position: The target is specified by a given position.

• Aim Muzzle Forward: Simply aims forward, where the character with the weapon is shooting at.

• Aim Top-Down Plane: Aims at a direction specified by the projection of the mouse over the plane where the character is. This option is perfect for top-down shooter games.

• Aim Top-Down Floor: Very similar to Top-Down Plane, but instead of shooting straight ahead where the eyes of the shooter are, the shot is performed where the mouse position intersects with geometry. This allows to shoot at enemies that are on a lower or upper level than the shooter.

• Aim Side-Scroll: Aims at a direction specified by the project of the mouse over the vertical plane of one side of the character. The plane (XY or ZY) can be also specified.

It is important to distinguish the difference between Aim at Target and Aim at Position. The first one will make the character keep track of the target while it is aiming, while the other one will remember the position of the target, but, if this one moves, it will still aim at where it was at the beginning.

As a rule of thumb, Aim at Target should only b used with the player, as you normally lock onto enemies. On the other hand, Aim at Position is usually used by enemies to simulate a flaw in their accuracy.

Shooting

Shooting a weapon is very simple. All that is needed is to use the Shoot Weapon Action. This will instruct the weapon to shoot. Depending on both the currently equipped Weapon and Ammo assets, the shot will be different.

However, there's a second type of shot that requires a different set of Actions: The charged shots.

Charged shots need a wind-up time before being released. An example of a charged shot are grenades, bows, Megaman's ArmGun, etc...

To start charging a shot you need to use the Weapon Start Charged Shot. To execute a charged shot you'll need to use the Weapon Execute Charged Shot.

Notice that nothing will happen if the Execute Charged Shot is issued before the Start Charged Shot.

Charged shots also have a minimum charge time, which defines the minimum time required to be able to shoot a charged shot. If the time between Start Charged Shot and Execute Charged Shot is less than the Min Charge Time field in the Ammo asset, the shot will not be made.

Receiving Damage

Receiving damage is an essential step in any game where any kind of shooting is involved. There are two ways to deal with damage output: The first one is using the built-in Action Lists provided by each Ammo asset. When shooting with any raycast or trajectory-cast projectiles, the Invoker will always reference the targeted object.

However, this does not give enough control. To solve this, there's the On Receive Shot Trigger, which is executed any time it received a shot. These shots can be filtered by weapon type and shot type (Any, Normal or Charged).

Raycast shooting modes will always automatically look for any On Receive Shot Trigger and call it. However, projectiles do not. In order for a Grenade or an Arrow (or any prefab projectile) to trigger the On Receive Shot, these need to use the Notify Shot Action.

For example, the Arrow projectile has a On Collision Enter Trigger which uses the Notify Shot Action to whatever object it collides with. The Grenade, on the other hand, collects all the objects affected by the blast and uses the Notify Shot Action in each one of them.