SceneKit, CIFilter. CICategoryBlur does not filter anything

Question

I am trying to blur a node or create a blur effect in SceneKit.

let ship = scene.rootNode.childNodeWithName("ship", recursively: true)! var ciFilters = [CIFilter]() ciFilters.append(CIFilter(name: "CIGaussianBlur", withInputParameters: [kCIInputRadiusKey: 30])!) ship.filters = ciFilters 

Results in:

What, I thought that maybe I'm using CIFilter incorrectly. However, CIHalftone works fine:

  ciFilters.append(CIFilter(name: "CICMYKHalftone", withInputParameters: ["inputWidth": 20])!) 

I also tried with CIZoomBlur not to work either, however CIPixellate does.

Did I miss something fundamental here?

Update: I tried everything in CICategoryBlur and cannot make them work, however every other CICategory element I tried to work with could work.

Thanks.