SpriteKit bodyWithTexture 未对齐

Question

我正在尝试在我的一些 sprite 上实现 bodyWithTexture，它在大多数情况下都很好用。我的问题是，出于某种原因，创建的物理体与我的精灵的实际形状不一致。我注意到它与纹理图集 Xcode 生成有关，它旋转有问题的精灵以适应。这是 issue.

的图像

我该如何解决这个问题？提前致谢！

注意：我试过这个的内容，但没有成功。注 2：我会在 Objective-C.

中使用任何代码示例

更新：这是用于设置物理体的所有代码。至于纹理，我让 SpriteKit 在幕后处理。

@implementation AsteroidNode

+(instancetype)astroidOfType:(AstoridType)type {

      AsteroidNode *astroid;

    if (type == AstoridTypeA) {
        astroid = [self spriteNodeWithImageNamed:@"rock_a"];
        astroid.type = AstoridTypeA;
    } else if (type == AstoridTypeB) {
        astroid = [self spriteNodeWithImageNamed:@"rock_b"];
        astroid.type = AstoridTypeB;
    } else {
        astroid = [self spriteNodeWithImageNamed:@"rock_c"];
        astroid.type = AstoridTypeC;
    }

    astroid.name = @"astroid";
    astroid.zPosition = 1;

    //changes asteroid size for smaller screen sizes
    if ( IS_IPHONE_4_OR_LESS | IS_IPHONE_5) {
        astroid.size = [Utils setNodeSize:astroid.size];
    }
    [astroid setUpPhysicsBody];

    return astroid;
}

-(void)setUpPhysicsBody {   
    self.physicsBody = [SKPhysicsBody bodyWithTexture:self.texture size:self.size];
    self.physicsBody.friction = 0;
    self.physicsBody.linearDamping = 0;
    self.physicsBody.categoryBitMask = CollisionCatAstroid;
    self.physicsBody.collisionBitMask = 0;
    self.physicsBody.contactTestBitMask = CollisionCatShip | CollisionCatBottomEdge;
}
@end

使用 bodyWithPolygonFromPath 在 6 和 6+ 上效果很好，但在 5 和 4S 上效果不佳。

CGFloat offsetX = self.size.width / 2;
CGFloat offsetY = self.size.height / 2;

if (self.type == AstoridTypeA) {
    CGMutablePathRef path = CGPathCreateMutable();

    CGPathMoveToPoint(path, NULL, 20 - offsetX, 87 - offsetY);
    CGPathAddLineToPoint(path, NULL, 77 - offsetX, 86 - offsetY);
    CGPathAddLineToPoint(path, NULL, 103 - offsetX, 48 - offsetY);
    CGPathAddLineToPoint(path, NULL, 88 - offsetX, 13 - offsetY);
    CGPathAddLineToPoint(path, NULL, 63 - offsetX, 16 - offsetY);
    CGPathAddLineToPoint(path, NULL, 33 - offsetX, 5 - offsetY);
    CGPathAddLineToPoint(path, NULL, 3 - offsetX, 36 - offsetY);

    CGPathCloseSubpath(path);

    self.physicsBody = [SKPhysicsBody bodyWithPolygonFromPath:path];
} else if (self.type == AstoridTypeB) {
    CGMutablePathRef path = CGPathCreateMutable();

    CGPathMoveToPoint(path, NULL, 43 - offsetX, 91 - offsetY);
    CGPathAddLineToPoint(path, NULL, 81 - offsetX, 80 - offsetY);
    CGPathAddLineToPoint(path, NULL, 97 - offsetX, 50 - offsetY);
    CGPathAddLineToPoint(path, NULL, 75 - offsetX, 10 - offsetY);
    CGPathAddLineToPoint(path, NULL, 25 - offsetX, 18 - offsetY);
    CGPathAddLineToPoint(path, NULL, 12 - offsetX, 36 - offsetY);
    CGPathAddLineToPoint(path, NULL, 10 - offsetX, 71 - offsetY);

    CGPathCloseSubpath(path);

    self.physicsBody = [SKPhysicsBody bodyWithPolygonFromPath:path];
} else {
    CGMutablePathRef path = CGPathCreateMutable();

    CGPathMoveToPoint(path, NULL, 41 - offsetX, 48 - offsetY);
    CGPathAddLineToPoint(path, NULL, 55 - offsetX, 32 - offsetY);
    CGPathAddLineToPoint(path, NULL, 40 - offsetX, 10 - offsetY);
    CGPathAddLineToPoint(path, NULL, 24 - offsetX, 12 - offsetY);
    CGPathAddLineToPoint(path, NULL, 11 - offsetX, 23 - offsetY);
    CGPathAddLineToPoint(path, NULL, 17 - offsetX, 43 - offsetY);

    CGPathCloseSubpath(path);
    self.physicsBody = [SKPhysicsBody bodyWithPolygonFromPath:path];
}

我最终得到了这个，可能是一种更简单的方法，但它有效。如果有人有任何建议，请告诉我。

   -(void)setUpPhysicsBody {
        CGFloat offsetX = self.size.width / 2;
        CGFloat offsetY = self.size.height / 2;

        if (self.type == AstoridTypeA) {
            if (IS_IPHONE_4_OR_LESS | IS_IPHONE_5) {
                CGMutablePathRef path = CGPathCreateMutable();

                CGPathMoveToPoint(path, NULL, 17 - offsetX, 72 - offsetY);
                CGPathAddLineToPoint(path, NULL, 64 - offsetX, 71 - offsetY);
                CGPathAddLineToPoint(path, NULL, 85 - offsetX, 40 - offsetY);
                CGPathAddLineToPoint(path, NULL, 73 - offsetX, 10 - offsetY);
                CGPathAddLineToPoint(path, NULL, 52 - offsetX, 13 - offsetY);
                CGPathAddLineToPoint(path, NULL, 27 - offsetX, 4 - offsetY);
                CGPathAddLineToPoint(path, NULL, 2 - offsetX, 30 - offsetY);

                CGPathCloseSubpath(path);

                self.physicsBody = [SKPhysicsBody bodyWithPolygonFromPath:path];
            } else {
                CGMutablePathRef path = CGPathCreateMutable();

                CGPathMoveToPoint(path, NULL, 20 - offsetX, 87 - offsetY);
                CGPathAddLineToPoint(path, NULL, 77 - offsetX, 86 - offsetY);
                CGPathAddLineToPoint(path, NULL, 103 - offsetX, 48 - offsetY);
                CGPathAddLineToPoint(path, NULL, 88 - offsetX, 13 - offsetY);
                CGPathAddLineToPoint(path, NULL, 63 - offsetX, 16 - offsetY);
                CGPathAddLineToPoint(path, NULL, 33 - offsetX, 5 - offsetY);
                CGPathAddLineToPoint(path, NULL, 3 - offsetX, 36 - offsetY);

                CGPathCloseSubpath(path);

                self.physicsBody = [SKPhysicsBody bodyWithPolygonFromPath:path];
            }
          } else if (self.type == AstoridTypeB) {
            if (IS_IPHONE_4_OR_LESS | IS_IPHONE_5) {
                CGMutablePathRef path = CGPathCreateMutable();

                CGPathMoveToPoint(path, NULL, 35 - offsetX, 75 - offsetY);
                CGPathAddLineToPoint(path, NULL, 67 - offsetX, 66 - offsetY);
                CGPathAddLineToPoint(path, NULL, 80 - offsetX, 41 - offsetY);
                CGPathAddLineToPoint(path, NULL, 62 - offsetX, 8 - offsetY);
                CGPathAddLineToPoint(path, NULL, 20 - offsetX, 15 - offsetY);
                CGPathAddLineToPoint(path, NULL, 10 - offsetX, 30 - offsetY);
                CGPathAddLineToPoint(path, NULL, 8 - offsetX, 59 - offsetY);

                CGPathCloseSubpath(path);
                self.physicsBody = [SKPhysicsBody bodyWithPolygonFromPath:path];
            } else {
                CGMutablePathRef path = CGPathCreateMutable();

                CGPathMoveToPoint(path, NULL, 43 - offsetX, 91 - offsetY);
                CGPathAddLineToPoint(path, NULL, 81 - offsetX, 80 - offsetY);
                CGPathAddLineToPoint(path, NULL, 97 - offsetX, 50 - offsetY);
                CGPathAddLineToPoint(path, NULL, 75 - offsetX, 10 - offsetY);
                CGPathAddLineToPoint(path, NULL, 25 - offsetX, 18 - offsetY);
                CGPathAddLineToPoint(path, NULL, 12 - offsetX, 36 - offsetY);
                CGPathAddLineToPoint(path, NULL, 10 - offsetX, 71 - offsetY);

                CGPathCloseSubpath(path);

                self.physicsBody = [SKPhysicsBody bodyWithPolygonFromPath:path];
            }
        } else {

            if (IS_IPHONE_4_OR_LESS | IS_IPHONE_5) {
                CGMutablePathRef path = CGPathCreateMutable();

                CGPathMoveToPoint(path, NULL, 34 - offsetX, 40 - offsetY);
                CGPathAddLineToPoint(path, NULL, 45 - offsetX, 26 - offsetY);
                CGPathAddLineToPoint(path, NULL, 33 - offsetX, 8 - offsetY);
                CGPathAddLineToPoint(path, NULL, 20 - offsetX, 10 - offsetY);
                CGPathAddLineToPoint(path, NULL, 9 - offsetX, 19 - offsetY);
                CGPathAddLineToPoint(path, NULL, 14 - offsetX, 35 - offsetY);

                CGPathCloseSubpath(path);

                self.physicsBody = [SKPhysicsBody bodyWithPolygonFromPath:path]; 
            } else {
                CGMutablePathRef path = CGPathCreateMutable();

                CGPathMoveToPoint(path, NULL, 41 - offsetX, 48 - offsetY);
                CGPathAddLineToPoint(path, NULL, 55 - offsetX, 32 - offsetY);
                CGPathAddLineToPoint(path, NULL, 40 - offsetX, 10 - offsetY);
                CGPathAddLineToPoint(path, NULL, 24 - offsetX, 12 - offsetY);
                CGPathAddLineToPoint(path, NULL, 11 - offsetX, 23 - offsetY);
                CGPathAddLineToPoint(path, NULL, 17 - offsetX, 43 - offsetY);

                CGPathCloseSubpath(path);

                self.physicsBody = [SKPhysicsBody bodyWithPolygonFromPath:path];
            }
        }

        self.physicsBody.friction = 0;
        self.physicsBody.linearDamping = 0;
        self.physicsBody.categoryBitMask = CollisionCatAstroid;
        self.physicsBody.collisionBitMask = 0;
        self.physicsBody.contactTestBitMask = CollisionCatShip | CollisionCatBottomEdge;
    }

Answer 1

您遇到了 bodyWithTexture 方法的 sprite-kit 错误。

物理体实际上是颠倒的，没有错位或旋转。因此它与 .

完全相同

这是 iOS8 上 Spritekit 中的一个错误。我怀疑当物理体的纹理从内部缓存中检索时会出现错误。尝试从 CoreGraphics 校正坐标系可能会错误地翻转图像。

在你的情况下，考虑到你的小行星的形状，我推荐这个：

init!(polygonFromPath path: CGPath!) -> SKPhysicsBody

Answer 2

根据您发布的代码，您使用的是图像而不是精灵纹理。

至于旋转的精灵，SK 确实需要 space 优化来创建纹理图集。这包括图像旋转和修剪。我怀疑你在 SK 将旋转设置回它应该的位置之前添加了一个物理体。返回小行星后尝试添加物理体。

如果这不能解决您的问题，我建议您使用像 Texture Packer 这样的应用创建您自己的纹理图集。 Texture Packer 的功能之一是 allow/disallow 图像旋转。

苹果docs关于SK如何实现纹理图集的说法，供大家参考：

After the app is built, new folders are created with a .atlasc suffix and placed in your app bundle’s Resource folder. Those new images are automatically rotated and trimmed to fit the maximum number of images into a single file, one whose images and orientation are tracked by a property list (.plist) associated with the folder. You do not need to change your code in order to use the texture atlas feature.

这是Apple使用的插图（注意旋转）：

SpriteKit bodyWithTexture 未对齐

SpriteKit bodyWithTexture misaligned

objective-c

ios

sprite-kit