In SceneKit we can not create PhysicalBody at every location, is that normal? - ios

Question

At sceneView we have a big cube.
SCNBox(width: 10, height:10, length: 10, chamferRadius: 0)
We are placing spheres(radius = 1) on the six surfaces of that bigger cube.
Spheres have dynamic physicalBody.
Debugger mode is active with
sceneView.debugOptions = [.showPhysicsFields, .showPhysicsShapes]
When we run app we can see that only sphere with node position
SCNVector3(x:0, y: 0, z: 10.5)
seems to have body, only this one marked by debugger.
Also, only this sphere responds if a kinetic body touches it.
Is there something we are missing, why the spheres on other surfaces can not have physical body.
This is how I create spheres;
var ball:[SCNSphere] = []
var ballNode:[SCNSNode] = []
var body:[SCNPhysicsBody] = []
let pShape = SCNSphere()
pShape.radius = 1
pShape.segmentCount = 1
for k in 0..<6 {
ball.append(SCNSphere())
ballNode.append(SCNSphere())
ball[k].radius = 1
ball[k].hunt.firstMaterial?.diffuse.contents = UIColor.red
ballNode[k]= SCNNode(geometry:ball[k])
let shape = SCNPhysicsShape(geometry: pShape, options: nil)
body.append(SCNPhysicsBody())
body[k] = SCNPhysicsBody(type: .dynamic, shape: shape)
body[k].isAffectedByGravity = false
body[k].friction = 1
body[k].restitution = 0.1
body[k].angularDamping = 1
ballNode[k].physicsBody = body[k]
let coors = createCoors(index: k)
ballNode.position = SCNVector3(coors.x, coors.y, coors.z)
bigBoxNode.addChildNode(ballNode[k])
}