world.getChildByName()

totebo

Hi guys, my first post!

I've started playing with Gideros and so far it's been plain sailing. That was until the point I needed to reference an Box2D body by its name. It seems Box2D has a world.getChildByName() method, which I can't seem to find a reference to in the Gideros Physics API.

Is this a missing feature, or is there another way I can reference an arbitrary body based on its name?

To give a bit of context, I have two bodies, one which contains a sensor fixture, the other a kinematic fixture. When the game character touches the sensor fixture I want to:

- Remove the sensor fixture (done)
- Add velocity to the kinematic fixture

Since the kinematic fixture is not actually part of a collision, I need another way of referencing it. Hope this makes sense.

Nic.

ar2rsawseen

Hello @totebo
I see,
usually I either create a class for an object, store them as class properties and add class instance reference to bodies (or fixtures)

as

MyPhysicsObject = Core.class()   function MyPhysicsObject:init() self.body1 = world:createBody{type = b2.STATIC_BODY} self.body1.object = self self.body2 = world:createBody{type = b2.STATIC_BODY} self.body1.object = self end   function MyPhysicsObject:getBody2() return self.body2 end   --and use it like   function scene:onBeginContact(e) --getting contact bodies local fixtureA = e.fixtureA local fixtureB = e.fixtureB local bodyA = fixtureA:getBody() local bodyB = fixtureB:getBody()   body2 = bodyA.object:ģetBody2() end

But probably can be done even easier, like

local body1 = world:createBody{type = b2.STATIC_BODY} local body2 = world:createBody{type = b2.STATIC_BODY} body1.body2 = body2   --and use it like   function scene:onBeginContact(e) --getting contact bodies local fixtureA = e.fixtureA local fixtureB = e.fixtureB local bodyA = fixtureA:getBody() local bodyB = fixtureB:getBody()   body2 = bodyA.body2 end

But I have not heard about world.getChildByName(), must be something new then, or some framework specific

totebo

Hi ar2, I've read many of your (very helpful) posts before, but hadn't experienced the extreme speed at which you operate!

Thanks for the response, that makes perfect sense, and feels a bit cleaner since you'd be able to call the second object immediately without any searching.

The thread I found mentioning .getChildByName() was on the Box2D forum where they remove a second object with this code (I'm not allowed to post links, but a google search should get you there):

Util.remove(world.getChildByName('instance_name_of_object'));

On a separate note, is there a legend for formatting codes to post to this forum?

Nic.

ar2rsawseen

About formating code, this can help
http://members.giderosmobile.com/knowledgebase.php?action=displayarticle&id=41