How to make one body stick to another moving object in SpriteKit

问题

I have an object moving along the X-axis, while the other body rests. After a collision is made, I wish the resting object move along with the moving object.

I use this code to move the first body:

    SKAction* moveBlock = [SKAction moveByX:-distanceToMove y:0 duration:0.01 * distanceToMove];
    SKAction* removeBlock = [SKAction removeFromParent];
    _moveBlocksAndRemove = [SKAction sequence:@[moveBlock, removeBlock]];

and in the collision detection I have tried to set a friction:

if (firstBody.categoryBitMask == categoryA && secondBody.categoryBitMask == categoryB) {
            firstBody.friction = 1.0;
            secondBody.friction = 1.0;
}

But that didn't work. applying velocity of the first body won't work since its velocity = 0;

Any ideas?

回答1:

I haven't tried that but it seems you want to add SKPhysicsJoint to the scene:

if (firstBody.categoryBitMask == categoryA && 
                 secondBody.categoryBitMask == categoryB) {
    SKPhysicsJointFixed* pin =
                    [SKPhysicsJointFixed jointWithBodyA:firstBody 
                                                  bodyB:secondBody 
                                                 anchor:firstBody.position];
    [self.physicsWorld addJoint:pin];
}

来源：https://stackoverflow.com/questions/22083604/how-to-make-one-body-stick-to-another-moving-object-in-spritekit