ios - 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 Sprite 的实际形状不一致。我注意到它与 Xcode 生成的纹理图集有关，它会旋转相关的 Sprite 以适应。这是 issue. 的图片

我该如何解决这个问题？提前致谢!

注:这个post的内容我都试过了没有运气。注 2:我会使用 Objective-C 中的任何代码示例。

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 this issue 完全相同.

这是 iOS8 上 Spritekit 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。它可能会错误地翻转图像以尝试更正来自 CoreGraphics 的坐标系。

在你的情况下，鉴于你的小行星的形状，我推荐这个:

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