shader
A text file that defines code that does custom per-pixel drawing or colorization.
Declaration
var shader: SKShader? { get set }Mentioned in
Discussion
The default value is nil, which means the default behavior for sprite rendering is performed. SpriteKit implements many sprite features using a default shader, such as:
Animations on alpha.
SKTexturefilteringMode.Light from SKLightNode.
If you supply a custom value for shader, your custom shader overrides the default shader which neutralizes the default features. It is the responsibility of your custom shader to implement any of the features your sprites require.