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我创建了一个非常简单的示例代码，只有一个场景，一个精灵节点 20x20px，位于屏幕上的 0.0 点。当我调用scene.physicsWorld bodyAtPoint它时，即使在例如：34x34 时也会返回这个节点。但在点 35x35 它返回null。所以基本上两个轴上从 0px 到 34px 的所有点都返回这个节点，从 35px 开始，它不再返回它了。如果精灵明显以 20px 20px 结束，知道可能是什么原因吗？在 中可以看到相同的行为bodyInRect。

这是示例代码：

-(id)initWithSize:(CGSize)size {    
if (self = [super initWithSize:size]) {
    /* Setup your scene here */

    self.backgroundColor = [SKColor colorWithRed:0.15 green:0.15 blue:0.3 alpha:1.0];
    self.physicsWorld.gravity = CGVectorMake(0, 0);

    SKSpriteNode *node = [[SKSpriteNode alloc] initWithColor:[UIColor whiteColor] size:CGSizeMake(20, 20)];
    node.position = CGPointMake(10, 10);

    node.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:CGSizeMake(20, 20)];
    [self addChild:node];

}
return self;
}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

for (UITouch *touch in touches) {
    CGPoint location = [touch locationInNode:self];
    if([self.physicsWorld bodyAtPoint:location])
    {
        NSLog(@"Detected at point: %f %f", location.x, location.y);
    }else{
        NSLog(@"No node at point: %f %f", location.x, location.y);
    }
}
}

这是控制台日志：

2013-11-09 15:05:52.822 SKTest[43143:70b] Detected at point: 2.000000 1.000000
2013-11-09 15:05:56.274 SKTest[43143:70b] Detected at point: 3.000000 7.000000
2013-11-09 15:05:57.006 SKTest[43143:70b] Detected at point: 3.000000 11.000000
2013-11-09 15:05:58.199 SKTest[43143:70b] Detected at point: 3.000000 12.000000
2013-11-09 15:05:58.918 SKTest[43143:70b] Detected at point: 3.000000 14.000000
2013-11-09 15:05:59.785 SKTest[43143:70b] Detected at point: 3.000000 17.000000
2013-11-09 15:06:00.685 SKTest[43143:70b] Detected at point: 3.000000 20.000000
2013-11-09 15:06:01.565 SKTest[43143:70b] Detected at point: 3.000000 22.000000
2013-11-09 15:06:02.915 SKTest[43143:70b] Detected at point: 3.000000 25.000000
2013-11-09 15:06:04.285 SKTest[43143:70b] Detected at point: 3.000000 30.000000
2013-11-09 15:06:05.387 SKTest[43143:70b] Detected at point: 3.000000 34.000000
2013-11-09 15:06:08.492 SKTest[43143:70b] No node at point: 4.000000 38.000000
2013-11-09 15:06:12.499 SKTest[43143:70b] Detected at point: 4.000000 5.000000
2013-11-09 15:06:13.240 SKTest[43143:70b] Detected at point: 6.000000 5.000000
2013-11-09 15:06:13.881 SKTest[43143:70b] Detected at point: 10.000000 5.000000
2013-11-09 15:06:15.064 SKTest[43143:70b] Detected at point: 12.000000 5.000000
2013-11-09 15:06:16.120 SKTest[43143:70b] Detected at point: 14.000000 5.000000
2013-11-09 15:06:16.873 SKTest[43143:70b] Detected at point: 16.000000 5.000000
2013-11-09 15:06:17.582 SKTest[43143:70b] Detected at point: 18.000000 5.000000
2013-11-09 15:06:18.066 SKTest[43143:70b] Detected at point: 21.000000 5.000000
2013-11-09 15:06:18.966 SKTest[43143:70b] Detected at point: 24.000000 5.000000
2013-11-09 15:06:19.585 SKTest[43143:70b] Detected at point: 31.000000 5.000000
2013-11-09 15:06:20.531 SKTest[43143:70b] Detected at point: 35.000000 5.000000
2013-11-09 15:06:22.581 SKTest[43143:70b] No node at point: 36.000000 4.000000
2013-11-09 15:06:26.560 SKTest[43143:70b] Detected at point: 19.000000 16.000000
2013-11-09 15:06:27.933 SKTest[43143:70b] Detected at point: 20.000000 17.000000
2013-11-09 15:06:29.856 SKTest[43143:70b] Detected at point: 25.000000 19.000000
2013-11-09 15:06:31.487 SKTest[43143:70b] Detected at point: 26.000000 22.000000
2013-11-09 15:06:33.850 SKTest[43143:70b] Detected at point: 29.000000 27.000000
2013-11-09 15:06:35.492 SKTest[43143:70b] Detected at point: 31.000000 29.000000
2013-11-09 15:06:36.854 SKTest[43143:70b] Detected at point: 35.000000 32.000000
2013-11-09 15:06:40.004 SKTest[43143:70b] No node at point: 40.000000 34.000000

是否有可能是 Apple 的错误，在nodeAtPoint和中都有nodeInRect吗？难以相信。但是代码太短了，我看不出这里有什么错误。任何帮助将不胜感激。

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1 回答 1

0

我对此进行了一些实验。当我放大精灵时，我注意到身体区域似乎比精灵大。我必须将精灵大小除以 1.15 以使身体矩形与所有 4 个侧面上显示的精灵大致匹配。不过不知道为什么。我从来没有遇到过游戏问题，所以也许 nodeAtPoint 有一个阈值范围？

SKSpriteNode *node = [SKSpriteNode spriteNodetWithColor:[SKColor whiteColor]
                                                   size:CGSizeMake(200, 200)];
node.position = CGPointMake(200, 200);

CGRect bodySize = CGSizeMake(node.size.width / 1.15, node.size.height / 1.15);
node.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:bodySize];
[self addChild:node];

我在 Retina 4" 和非 Retina iPad 模拟器上对此进行了测试。

于 2013-11-09T22:26:12.437 回答