Hi all! I'm a paying owner of the game edition and have a support ticket from Ansca open for 11 days (case 2184) and wrote them again in the meantime but I'm still waiting for a reply. Is there any other way to contact Ansca? I've tried both support@ansca.com and now also support@anscamobile.com. I received one auto-reply telling me that my case was being worked on but haven't heard anything after this, or I can't find that email.

For what it's worth, I'm still puzzled how to create one-sided platforms. I've tried cancelling the preCollision event (which doesn't seem to prevent the collision, but only one's subscribed collision event handlers) and I've tried toggling isSensor, which gets ignored. Still optimistic to get it to work. If you're an expert Corona developer and you do paid support please let me know :)

Phillip,

am looking at it right now.

c.

Hi Phillip,

I haven't actually tried this myself yet, but Jon Beebe posted about an approach to this problem that he got working:

http://developer.anscamobile.com/forum/2010/08/29/help-one-sided-platforms#comment-5461

Hopefully this helps.

Tim

Thank you for the link Tim. I figured by now that I might need to use sensors, after unsuccessfully trying to go the preCollision route the tutorial mentions (I agree with Jon, it might be better to remove that from the tutorial, or fully explain how it works). In my case I actually might not be able to use Jon's precise approach because I need the platform to normally interact with other objects -- so it must be there, and collide with stuff -- but perhaps I can simply disable collisions of this platform object with the player character altogether and emulate the stop myself by forcing the y velocity to be zero. Will see where this road leads...

PS: Can't agree more with this feature request :) http://developer.anscamobile.com/forum/2010/12/10/override-contact-precollision-box2d-contactsetenabledfalse

Although there is a solution for the one-sided platforms, it is not ideal. The solution presented with swapping sensor platforms with non sensor platforms fail if you have more than one character. For example, multiple enemies chasing your character or multiple pinballs going through gates.

What I would like to have (more like NEED) is the ability to cancel individual collisions. In the Flash port, I was able to cancel these collisions by doing something like so:

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package  {
 
        import Box2D.Collision.b2Manifold;
        import Box2D.Dynamics.b2EmptyContactListener;
        import Box2D.Dynamics.Contacts.b2Contact;
 
        public class PCollider extends b2EmptyContactListener {
 
                override public function PreSolve($contact:b2Contact, $oldManifold:b2Manifold):void {
                        // check if object is not on top of platform
                        var isNotOnTop = ...
                        if (isNotOnTop){
                                $contact.SetEnabled(false);
                        }
                }
        }
}