Adding an Extra Collider

[cemalgnlts]

Hi,

My bomb object already has a collider so it stays on the floor, but when it explodes I want to add a circle collider so I can access the objects within the area it exploded.

There is information about changing it in the document, but I want to add one more.

(I saw the Trigger class but wanted to know if it is added to the actor object.)

[cemalgnlts]

I misunderstood the Trigger class a bit. The Trigger indicates that it has collided with another object. I need more control.

I tried adding an Actor instead:

// Capture objects colliding with the circle.
const actor = new ex.Actor({
  pos: this.pos,
  radius: 45,
  collisionType: ex.CollisionType.Passive,
  collider: ex.Shape.Circle(50),
  color: ex.Color.Black,
});

actor.on("postcollision", (ev) => console.log(ev));

this.scene.add(actor);

But this way I can't listen to the collision event. Shouldn't ex.CollisionType.Passive help listen for collision event?

[eonarheim]

@cemalgnlts Good question, this is definitely the approach I would suggest for your bomb using another actor/entity with a circle collider. You could add an additional trigger/actor to the top level scene, or as a child on the bomb actor.

When the collision type is ex.CollisionType.Passive the postcollision event doesn't fire because no resolution was performed.

You can use the collisionstart and collisionend events, here is an example of using this kind of approach to enable 1-way platforms.
#2577 (reply in thread)

There is more documentation about the specific events here https://excaliburjs.com/docs/collision-events/#collision-start-collisionstart

[cemalgnlts]

Thanks,
I'm glad to see this example, I just completed it like this:

const colliderComp = new ex.ColliderComponent(ex.Shape.Circle(50));
const bodyComp = new ex.BodyComponent();

const explosion = new ex.Entity([
  colliderComp,
  bodyComp
], "explode");

bodyComp.collisionType = ex.CollisionType.Passive;
bodyComp.group = ex.CollisionGroup.collidesWith([
  ex.CollisionGroupManager.groupByName("player")
]);

colliderComp.events.on("collisionstart", (ev) => this.onExplodeInteract(ev));

this.addChild(explosion);