For complex applications, you might manage multiple scenes:

// Create multiple scenes
const gameScene = new BABYLON.Scene(engine);
const uiScene = new BABYLON.Scene(engine);

// Switch between scenes
let activeScene = gameScene;

engine.runRenderLoop(() => {
    activeScene.render();
});

// Function to switch scenes
function switchToUIScene() {
    activeScene = uiScene;
}