Q:

Where find contactPoint between 2 physics bodies ?

I'm trying to display a label where the contact between to physics bodies occurred but I can't find it.
Someone can help me?
thank you

A:

I find by myself how display a label on the contact position between two physics bodies.
the secondBody.node is called 'balloon' so I can follow it and use his position.
if ((firstBody.categoryBitMask & flechetteCategory) != 0 && (secondBody.categoryBitMask & blueCategory) != 0)
    {
        flecheDidCollideWithBlueBalloon(firstBody.node as SKSpriteNode, balloon: secondBody.node as   SKSpriteNode)
    }

return this function : 
func flecheDidCollideWithBlueBalloon (fleche: SKSpriteNode, balloon: SKSpriteNode)
{
    self.runAction(SKAction.playSoundFileNamed("eclate.mp3", waitForCompletion: false))

    println("blue")
    fleche.removeFromParent()
    balloon.removeFromParent()

    blueDestroyed++

    //dysplay +1
    labelScoreB.position = balloon.position
    addChild(labelScoreB)

    let moveAction = SKAction.moveBy(CGVector(dx: 0, dy: 3), duration: 0.3)
    moveAction.timingMode = .EaseOut
    labelScoreB.runAction(SKAction.sequence([moveAction, SKAction.removeFromParent()]))

    self.scoreBlue.text = String(self.blueDestroyed)

}

