In SpriteKit, SKCropNode has no effect over a SKShapeNode

Question

I\'ve been trying to apply a mask to a SKShapeNode using SKCropNode, and so far without success. Thinking that it\'s a SpriteKit bug - Here is the code snippet:

Answer 1

Your title is correct. I've also discovered having a ShapeNode in the CropNode's hierarchy affects the children above it as well. I created a quick experiment. You can create a new game project and try it yourself. By commenting out one of the addChild:shapeContent lines you can see how it affects the cropping of the spaceship image.

As DoctorClod points out the current solution seems to be making sure all children of the cropNode are SpriteNodes.

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

SKSpriteNode* colorBackground = [SKSpriteNode spriteNodeWithColor:[SKColor redColor] size:CGSizeMake(800, 600)];

SKSpriteNode *spaceshipImage = [SKSpriteNode spriteNodeWithImageNamed:@"Spaceship"];

SKShapeNode* shapeContent = [SKShapeNode shapeNodeWithRect:CGRectMake(0, 0, 200, 100)];
shapeContent.fillColor = [SKColor greenColor];

SKSpriteNode *maskShape  = [SKSpriteNode spriteNodeWithColor:[SKColor blackColor] size:CGSizeMake(500, 100)];

SKCropNode *cropNode = [SKCropNode new];

[cropNode addChild:colorBackground];
[cropNode addChild:shapeContent];     // comment this one out
[cropNode addChild:spaceshipImage];
[cropNode addChild:shapeContent];     // or comment this one out

[cropNode setMaskNode:maskShape];

cropNode.position = CGPointMake(CGRectGetMidX (self.frame), CGRectGetMidY(self.frame));
[self addChild:cropNode];
}