How to detect contact on different areas of a physicsbody

Question

I would like to achieve the classic \'headshot\' effect in a sprite-kit game.

My ideas and attempts:

1. Create separate \'body\' and \'head\' physicsBodies

Answer 1

I use this setup in a lot of places. It scales pretty well if you find yourself wanting to add more parts, or weapons, and it lets you visually hide any of those parts or weapons easily. The use of userData can come in handy if you have a lot going on and different enemies have different "things", or you're doing crazy stuff like parenting child sprites to different entities based on gameplay, etc.

-(SKSpriteNode*)makeAnEnemy
{

    SKSpriteNode *mainEnemy;
    SKSpriteNode *enemyHead;
    //setup mainEnemy physics body
    //setup enemyHead physics body
    [mainEnemy addChild:enemyHead];

    // depending on your plans, on hit you could use the following code later:
    SKSpriteNode *theEnemyThatWasHit = (SKSpriteNode*)enemyHead.parent;

    //or you can use userdata and set it all up here
    [mainEnemy.userData setObject:enemyHead forKey:@"myHead"];
    [enemyHead.userData setObject:mainEnemy forKey:@"myBody"];

    return mainEnemy;
}