Thanks to the answer provided here -- Programmatically create a UIView with color gradient -- I am able to set a color gradient for the background of the homescreen of my app.
Prior to programming the color gradient using a CAGradientLayer, the user would press a button on the homescreen, and my SCNScene would appear.
Now, with the gradient in place, I can't seem to get the SCNScene to appear. All I can see is the color gradient. I've tried constructing an SCNLayer "above" the CAGradientLayer, but XCode yells at me.
What gives? Shouldn't it be simple to display a CAGradientLayer in the background with an SCNScene in front of it? I'm relatively new to this - thanks in advance.