Objective c 以主角问题为中心的精灵套装

我一直在试图让一个相机在雪碧工具包工作，从文件。当我在didSimulatePhysics中调用centerOnNode方法时，我的角色仍然在屏幕上移动，而不是停留在中心。谁能告诉我我做错了什么。我在这里看到过类似的问题，但一直无法发现我做错了什么，我是新的雪碧套件

    @implementation MyScene

-(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.anchorPoint = CGPointMake (0.5,0.5);//centralise the scenes anchor point
        //self.size = CGSizeMake(1000,1000);

        //create a world node to represent the scrolling world
        SKNode *myWorld = [SKNode node];
        [self addChild:myWorld];

        SKNode *camera = [SKNode node];
        camera.name = @"camera";
        [myWorld addChild:camera];

        SKSpriteNode *sprite = [SKSpriteNode spriteNodeWithImageNamed:@"character.png"];
        sprite.name = @"player";
        sprite.position = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMidY(self.frame));

        [myWorld addChild:sprite];

        SKAction *myAction = [SKAction moveTo:CGPointMake(50, 50) duration:7];

        [sprite runAction:myAction];

    }
    return self;
}

- (void)didSimulatePhysics{
    [self centerOnNode: [self childNodeWithName: @"player"]];
    }

- (void) centerOnNode: (SKNode *) node{
    NSLog(@"in centerOnNode");
    CGPoint cameraPositionInScene = [node.scene convertPoint:node.position fromNode:node.parent];
    node.parent.position = CGPointMake(node.parent.position.x - cameraPositionInScene.x,
                                       node.parent.position.y - cameraPositionInScene.y);
    }

@end

    enter code here

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我找到了我需要的解决办法。我没有将摄影机和播放器节点拉入didSimulatePhysics，然后将摄影机节点位置设置为播放器节点位置。下面的例子实现了我想要的，但如果有人有更好的方法，请建议：

#import "MyScene.h"

@implementation MyScene

-(id)initWithSize:(CGSize)size {    
    if (self = [super initWithSize:size]) {

        self.backgroundColor = [SKColor colorWithRed:0.15 green:0.15 blue:0.3 alpha:1.0];
        self.anchorPoint = CGPointMake (0.5,0.5);//centralise the scenes anchor point
        self.size = CGSizeMake(2000,2000);//make scene bigger to see if world scrolls

        //create a world node to represent the scrolling world
        SKNode *myWorld = [SKNode node];
        myWorld.name = @"world";
        [self addChild:myWorld];

        //create a camera node
        SKNode *camera = [SKNode node];
        camera.name = @"camera";
        [myWorld addChild:camera];

        //create two sprites, one with a moveTo action
        SKSpriteNode *sprite = [SKSpriteNode spriteNodeWithImageNamed:@"character.png"];
        sprite.name = @"player";
        sprite.position = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMidY(self.frame));
        [myWorld addChild:sprite];//add sprite to world node

        SKAction *myAction = [SKAction moveTo:CGPointMake(500, 500) duration:10];
        [sprite runAction:myAction];

        SKSpriteNode *sprite2 = [SKSpriteNode spriteNodeWithImageNamed:@"character.png"];
        sprite2.name = @"player";
        sprite2.position = CGPointMake(CGRectGetMidX(self.frame)+50, CGRectGetMidY(self.frame)+50);
        [myWorld addChild:sprite2];//add sprite to world node
    }
    return self;
}


- (void)didSimulatePhysics{
    //pull in camera and player sprites
    SKNode *camera = [self childNodeWithName: @"//camera"];
    SKNode *playr = [self childNodeWithName: @"//player"];
    //position camera where player is
    camera.position = CGPointMake(playr.position.x, playr.position.y);
    //center world on the camera
    [self centerOnNode: camera];
}

- (void) centerOnNode: (SKNode *) node{
    CGPoint cameraPositionInScene = [node.scene convertPoint:node.position fromNode:node.parent];
    node.parent.position = CGPointMake(node.parent.position.x - cameraPositionInScene.x,
                                       node.parent.position.y - cameraPositionInScene.y);
    }
@end

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你的相机节点在哪里？对不起，我在创建和添加我的世界节点之后创建了这个。我已经在上面的问题中编辑了代码，但它仍然不起作用，当我将@“camera”传递给centerOnNode函数时，它不起作用。那么有人知道为什么我们需要使用@”//camera和@”//player而不是@“camera”和@“player”？//是什么意思？我猜这是因为摄影机不是场景的孩子。相机是世界的孩子，也是场景的孩子。