I created a circular mask and animate a sprite inside the mask by using sprite kit SKCropNode class. But the edge of the mask looks pixellated.
Is there a way to use anti-aliasing to smooth the edges?
I created a circular mask and animate a sprite inside the mask by using sprite kit SKCropNode class. But the edge of the mask looks pixellated.
Is there a way to use anti-aliasing to smooth the edges?
As of now (June 2018) I can confirm that the SKCropNode will do per-pixel alpha blending. If the crop node has an SKSpriteNode as a mask, and the mask node uses a texture with an anti-aliased mask image, the crop node will do the proper blending.
If you want to mask any SKNode/SKSpriteNode with an anti-aliasing effect - you can use SKEffectNode instead of SKCropNode. It works with animated nodes as well. Here is an example:
// Set up your node
SKNode *nodeToMask = [SKNode node];
// ...
// Set up the mask node
SKEffectNode *maskNode = [SKEffectNode node];
// Create a filter
CIImage *maskImage = [[CIImage alloc] initWithCGImage:[UIImage imageNamed:@"your_mask_image"].CGImage];
CIFilter *maskFilter = [CIFilter filterWithName:@"CISourceInCompositing"
keysAndValues:@"inputBackgroundImage", maskImage, nil];
// Set the filter
maskNode.filter = maskFilter;
// Add childs
[maskNode addChild:nodeToMask];
[scene addChild:maskNode];
From the official docs:
So, SKCropNode doesn't support per pixel alpha values. It either draws the pixels or it doesn't. If alpha (as is used by anti-aliasing) is important to you, you should consider alternative routes. For example:
How to Mask an UIImageView