Hit test a particle system in ARKit

I made a particle system attached to a base (a cylinder node) in the SceneKit editor. Screenshot

I then added it to the root node of the sceneView's scene via a hit test. I'm using ARWorldTrackingConfiguration.

Code Block swift/* crossHairPoint is the 2D point where I want to place the particle */let results = sceneView.hitTest(crossHairPoint, types: .existingPlaneUsingExtent)    if let hitResult = results.first {             let particleScene = SCNScene(named: "art.scnassets/lights.scn")!             let rootNode = particleScene.rootNode             rootNode.position = SCNVector3(        x: hitResult.worldTransform.columns.3.x,        y: hitResult.worldTransform.columns.3.y,        z: hitResult.worldTransform.columns.3.z      )             sceneView.scene.rootNode.addChildNode(rootNode)    }

Then, I would like to be able to move the particle system + cylinder when I drag it.

Hit testing works if I tap the base of the particle system (the cylinder), but hit testing the particle system itself doesn't work. Any suggestions?

Code Block languagelet hitNodeResults = sceneView.hitTest(location, options: [SCNHitTestOption.searchMode: 1])/* `searchMode` is from this Stack Overflow answer: https://stackoverflow.com/a/50109757 It's supposed to be able to hit multiple nodes and objects even when in front or behind of each other */  for hitResult in hitNodeResults {		/* ... never gets called when I tap the particle system */	}

I also tried wrapping the particle system in its own node, but it didn't work.