Ray tracing samples can now also use the UI overlay

General cleanup, changed default settings.overlay value

examples/offscreen/offscreen.cpp

@@ -88,7 +88,6 @@ public:
 		camera.setRotation(glm::vec3(-2.5f, 0.0f, 0.0f));
 		camera.setRotationSpeed(0.5f);
 		camera.setPerspective(60.0f, (float)width / (float)height, 0.1f, 256.0f);
-		settings.overlay = true;
 		// The scene shader uses a clipping plane, so this feature has to be enabled
 		enabledFeatures.shaderClipDistance = VK_TRUE;
 	}