Question

想要使用SKPhysics拖动SKSpriteNode（按照您的手指动作）（启用碰撞）

2个失败的解决方案：

1）

a）解决方案：更改SKSpriteNode的位置

b）问题：SKSpriteNode将会神奇地＆＃34;当用户快速通过墙壁拖动spriteNode时，意外地穿过墙壁（物理似乎不起作用）

c）代码：

@property (nonatomic) CGPoint translationBy;

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    UITouch *touch = [touches anyObject];
    CGPoint positionInScene = [touch locationInNode:self];
    [self selectNodeForTouch:positionInScene];
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    UITouch *touch = [touches anyObject];
    CGPoint positionInScene = [touch locationInNode:self];
    CGPoint previousPosition = [touch previousLocationInNode:self];

    CGPoint translation = CGPointMake(positionInScene.x - previousPosition.x, positionInScene.y - previousPosition.y);

    [self panForTranslation:translation];
}

- (void)panForTranslation:(CGPoint)translation {
    CGPoint position = [_selectedNode position];
    if([[_selectedNode name] isEqualToString:PLAYER_NAME]) {
        [_selectedNode setPosition:CGPointMake(position.x + translation.x, position.y + translation.y)];
    }
}

2）在这里搜索后发现advice来自@ LearnCocos2D＆＃34;当你使用物理时，坚持通过力，冲动或直接改变体速来移动物理体。＆＃34;所以我试过了：

a）解决方案：在精灵节点上施加脉冲。

b）问题：即使我没有拖动精灵节点，精灵节点也会继续移动。（表现得像一艘漂浮的船。一旦拖动停止，精灵节点将停止;预计它将像汽车一样;一旦拖动开始，它将跟随手指。）

c）代码：

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    UITouch *touch = [touches anyObject];
    CGPoint positionInScene = [touch locationInNode:self];
    [self selectNodeForTouch:positionInScene];
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    UITouch *touch = [touches anyObject];
    CGPoint positionInScene = [touch locationInNode:self];
    CGPoint previousPosition = [touch previousLocationInNode:self];

    CGPoint translation = CGPointMake(positionInScene.x - previousPosition.x, positionInScene.y - previousPosition.y);

    CGVector forceVector = CGVectorMake(translation.x, translation.y);
    [self.player.physicsBody applyImpulse:forceVector];
    //[self.player.physicsBody setVelocity:CGVectorMake(0, 0)];

}

- ＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT ;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;＆GT;

更新：

来自评论：＆＃34; i）您可以确定节点到手指位置的距离，然后在每次更新时设置速度：这样它将完全位于手指在下一帧的位置。 ii）如果手指和节点位置相同，这将抵消任何移动，否则节点将在执行所有物理碰撞时粘在您的手指上，并且在受阻的情况下将继续在自身和手指之间推动物体。＆＃ 34;

a）问题：如何禁用轻弹？

b）问题：精灵节点会在轻微（意外）轻弹的情况下移动很远。

c）代码：

@property (nonatomic) CGPoint translationBy;

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    UITouch *touch = [touches anyObject];
    CGPoint positionInScene = [touch locationInNode:self];
    CGPoint previousPosition = [touch previousLocationInNode:self];
    //    1) You could determine the distance of the node to the finger location,

    CGPoint xyTranslation = CGPointMake(positionInScene.x - previousPosition.x, positionInScene.y - previousPosition.y);
    if (fabsf(positionInScene.x - previousPosition.x) < kPlayerMovementThreshold) {
        xyTranslation.x  = 0;
    }
    if (fabsf(positionInScene.y - previousPosition.y) < kPlayerMovementThreshold) {
        xyTranslation.y = 0;
    }
    self.translationBy = xyTranslation;
}

static const CGFloat kPlayerMovementSpeed = 55.0f;

static const CGFloat kPlayerMovementThreshold = 1.0f;

-(void)update:(CFTimeInterval)currentTime{
     // ii) then set the velocity every update: so that it will exactly be on the finger's position the next frame.

    CGFloat dx = self.translationBy.x*kPlayerMovementSpeed;
    CGFloat dy = self.translationBy.y*kPlayerMovementSpeed;
    CGVector velocityVector = CGVectorMake(dx,dy);
    [self.player.physicsBody setVelocity:velocityVector];
}

Answer 1

我所做的是制作一个SKNode，我们称之为'a'，附带一个非常小的物理主体。这个新节点通过SKPhysicsJointSpring连接到我想要移动的节点，让我们称之为'b'。新节点a跟踪我的手指移动，弹簧确保目标节点b遵循该节点。因为节点b使用物理定位，所以碰撞检测按预期工作。

使用SKPhysics（碰撞）拖动SKSpriteNode（跟随手指移动）

1 个答案: