What is the correct way to render on demand

[hjlld]

try this https://codepen.io/hjlld/pen/wvzXmbM

you can switch render loop to camera.onViewMatrixChangedObservable.add( () => scene.render() )

//engine.runRenderLoop(renderLoop);

let camera = scene.activeCamera;
camera.onViewMatrixChangedObservable.add( () => renderLoop() )