Adding objects to the scene

Let's next add geometry to the scene. We can create basic geometry such as spheres, boxes, cones, tori, and so on in SceneKit with a lot of ease. Let's create a sphere first and add it to the scene.

Adding a sphere

Create a new function called addGeometryNodes in the GameViewController class, as follows:

func addGeometryNode() {

   let sphereGeometry = SCNSphere(radius: 1.0)
   sphereGeometry.firstMaterial?.diffuse.contents = UIColor.orange
        
   let sphereNode = SCNNode(geometry: sphereGeometry)
   sphereNode.position = SCNVector3Make(0.0, 0.0, 0.0)
   self.rootNode.addChildNode(sphereNode)        
}

We will use the SCNSphere class to create a sphere. We can also call SCNBox, SCNCone, SCNTorus, and so on to create a box, a cone, or a torus.

When creating a sphere, we have to provide the radius as a parameter, which will determine the size of the sphere. Although, to place the shape we have to attach it to a node so that we can add it to the scene...