sprite-kit - SpriteKit : No Collision Detection between Sprites.

Question

在 SpriteKit 中设置碰撞检测应该不是一件困难的事情，我以前也做过。然而，尽管在其他项目中成功地使用了它并且有大量关于该主题的文档，但我无法在我当前的项目中使用它，而且我不知道为什么。

上下文非常简单。我将球体 (SKSpriteNode) 添加到背景 Sprite，然后用手指移动它们，希望它们在相互接触时检测到碰撞。 (这不会发生)。

预期的结果是检测到碰撞。

场景设置:

@interface GameScene () <SKPhysicsContactDelegate>
...
@implementation GameScene

// Collision BitMask
static const uint32_t planetCategory =  0x1 << 0;

场景也将自己设置为 physicsWorld 的代理

[self.physicsWorld setContactDelegate:self];

我只为我的场景提供了一个碰撞位掩码，因为所有对象都是同一类型并且应该相互碰撞。我还设置了场景以遵守 SKPhysicsContactDelegate 协议(protocol)。

Sprite 配置:

#pragma mark Protocol Methods (For Adding Planets)
-(void)addSKPlanetDescriptorObject:(SKPlanetDescriptor *)object
{
    if (self.allowedNodes > 0){

        SKObject *node = [[SKObject alloc]initWithImageNamed:object.imageName];
        [node setDescriptor:object];

        // Set Physics
        [node.physicsBody setCategoryBitMask:planetCategory];
        [node.physicsBody setContactTestBitMask:planetCategory];
        [node.physicsBody setCollisionBitMask:planetCategory];

        [self.background addChild:node];
        [self.sceneObjects addObject:node];
        [node setPosition:self.pendingSpawnPoint];
        [self decreaseObjectCount];
    } else {
        [self indicateMinObjectCount];
    }
}

最后，用于 SKObject 的初始化器，它是 SKSpriteNode 的子类

@implementation SKObject


-(instancetype)initWithImageNamed:(NSString *)name
{
    self = [super initWithImageNamed:name];
    if (self)
    {
        [self setPhysicsBody:[SKPhysicsBody bodyWithCircleOfRadius:self.size.width/2]];
        [self.physicsBody setAffectedByGravity:NO];
        [self.physicsBody setUsesPreciseCollisionDetection:YES];
        [self.physicsBody setDynamic:YES];
        [self.physicsBody setMass:1000];
    }
    return self;
}

我试过在 init 语句之外删除 setPhysicsBody 方法，我试过更改位掩码，我试过省略 setCollisionBitmask 等等，但我就是想不通为什么我没有遇到任何碰撞。

我也添加了

-(void)didBeginContact:(SKPhysicsContact *)contact
{
    NSLog(@"Did Begin Contact");
}

如果检测到任何内容，使用换行符通知我。但是这个方法永远不会被触发。

Answer 1

使用这个与您的代码非常相似的简单代码(只需尝试拖动 Sprite )，我的一切都运行良好(使用 iPhone 6 模拟器)...请尝试此代码，看看它是否适合您:

#import "GameScene.h"
static const uint32_t planetCategory =  0x1 << 0;

@interface GameScene () <SKPhysicsContactDelegate>

@property (nonatomic,strong) SKSpriteNode *ball1;
@property (nonatomic,strong) SKSpriteNode *ball2;

@end

@implementation GameScene

-(void)didMoveToView:(SKView *)view {

    [self.physicsWorld setContactDelegate:self];

    SKSpriteNode *ball1 = [self createBall];

    // Set Physics
    [ball1.physicsBody setCategoryBitMask:planetCategory];
    [ball1.physicsBody setContactTestBitMask:planetCategory];
    [ball1.physicsBody setCollisionBitMask:planetCategory];
    ball1.position = CGPointMake(100,499);
    ball1.name = @"ball1";


    [self addChild:ball1];

    SKSpriteNode *ball2 = [self createBall];



    // Set Physics
    [ball2.physicsBody setCategoryBitMask:planetCategory];
    [ball2.physicsBody setContactTestBitMask:planetCategory];
    [ball2.physicsBody setCollisionBitMask:planetCategory];
    ball2.position = CGPointMake(100,123);
    ball2.name = @"ball2";


    [self addChild:ball2];


}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    /* Called when a touch begins */

}

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

    for (UITouch *touch in touches) {
        CGPoint location = [touch locationInNode:self];


        if([[self nodeAtPoint:location].name isEqualToString:@"ball1"]){

            [self childNodeWithName:@"ball1"].position = location;

        }
        if([[self nodeAtPoint:location].name isEqualToString:@"ball2"]){

            [self childNodeWithName:@"ball2"].position = location;


        }
    }
}

-(SKSpriteNode*) createBall{

    SKSpriteNode *ball = [[SKSpriteNode alloc] initWithImageNamed:@"balloon_large"];

    ball.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:ball.size.width/2];

    [ball.physicsBody setAffectedByGravity:NO];
    [ball.physicsBody setUsesPreciseCollisionDetection:YES];
    [ball.physicsBody setDynamic:YES];
    [ball.physicsBody setMass:1000];

    return ball;
}

-(void)update:(CFTimeInterval)currentTime {
    /* Called before each frame is rendered */
}

-(void)didBeginContact:(SKPhysicsContact *)contact
{
    NSLog(@"Did Begin Contact");
}

@end

如果您无法使用此代码段重现良好的结果，那么您可能需要检查代码的其他部分以找出导致这些问题的原因。但是让我们先试试这个，现在让我谈谈结果......