Ignore individual collisions between two objects

[armoredpokey]

I want to ignore collisions between an object and a special class of objects only when the collision contact point meets a few criteria. In other words:

function OnCollisionEnter(other : Collision) {
  if (isSpecial(other.gameObject) && meetsCriteria(other.contacts[0].point)) {
    // Ignore this individual collision
  }
}

However, I don’t want to use Physics.IgnoreCollision(other.collider, collider) because I want future collisions to still happen.

Any thoughts? I will probably have to default to some kind of hackery where I remember what colliders I’ve ignored and then reenable collisions later, but I’d like to have a cleaner and less hacky solution.

Thanks!

[whydoidoit]

Well you could flag special game objects by giving them a script (with perhaps even nothing in it!)

 if(other.gameObject.GetComponent<IsSpecial>())
 {
 }

Now as for meeting criteria - if these are fixed then you could obviously just code meetsCriteria - otherwise perhaps an event?

public class ContactPointCriteria
 {
      public ContactPoint point;
      public bool meetsCriteria;
 }

 public event Action<ContactPointCriteria> CheckContactPoint = delegate {};

Then

  var cpc = new ContactPointCriteria { point = other.contacts[0] };
  CheckContactPoint(cpc);
 if(other.gameObject.GetComponent<IsSpecial>() && cpc.meetsCriteria)
 {
 }

To wire up the event

  someClassInstance.CheckContactPoint += HandleContact;

  void HandleContact(ContactPointCriteria criteria)
  {
     criteria.meetsCriteria = true;//the result of some calculation
  }

Or you could keep that same ContactPointCriteria and send or broadcast a message:

  var cpc = new ContactPointCriteria { point = other.contacts[0] };
  BroadcastMessage("CheckContact", cpc, SendMessageOptions.DontRequireReceiver);
 if(other.gameObject.GetComponent<IsSpecial>() && cpc.meetsCriteria)
 {
 }

Then handling it on a suitable script would be

  void CheckContact(ContactPointCriteria criteria)
  {
     criteria.meetsCriteria = true;//the result of some calculation
  }