title: SceneKit – Why does adding spot light blacken the floor?
body: <p>Screenshot #1 shows a simple SceneKit scene with only an ambient light (explicitly added, not the default one).</p>
  
  <p>Screenshot #2 shows what happens after adding a spot light. The whole floor turns black. This spot light has the default properties after adding a spot light within the SceneKit Editor.</p>
  
  <p>This also happens with a directional light.</p>
  
  <p>To be clear, it is understood that the scene contains ambient lighting by default. However, we explicitly added an ambient light (and even tested with two) <em>before</em> adding the spot/directional light. So the default light theory mentioned in <a href="https://stackoverflow.com/questions/24697574/how-to-i-turn-off-the-ambient-light-in-scene-kit-with-swift">this question</a> no longer apply. Hence the confusion.</p>
  
  <p>Spot lights and directional lights are supposed to add light to a particular region of the scene, that is understood. But they shouldn't blacken areas outside their scope, right?</p>
  
  <p>New to 3D graphics and SceneKit so any advice is very much appreciated.</p>
  
  <p><strong>Screenshot #1:</strong>
  <a href="https://i.stack.imgur.com/I0h67.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/I0h67.png" alt="enter image description here"></a></p>
  
  <p><strong>Screenshot #2:</strong>
  <a href="https://i.stack.imgur.com/Eh5BJ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Eh5BJ.png" alt="enter image description here"></a></p>