ios - Animations of SpriteKit overlay on SceneKit stops when SceneKit animations stop -

i guess must have asked before, can't find right in meanwhile here goes.

animations of spritekit overlay on scenekit stops when scenekit animations stop. unexpected. it's whole scnview , children goes sleep 3d contents don't move. how can make spritekit scene animate independently of scenekit scene does? update: have confirmed if add simple 3d box rotates indefinitely , keep in view somewhere, 3d scene not "sleep" , neither overlay. there setting somewhere stop scenekit part sleeping?

background: use scnview.overlayskscene. have indefinitely repeating animation of 1 of subnodes of overlay. action and/or animation goes on in scenekit scene, overlay 2d stuff animates, stops 3d animations stop.

ios 9.2.1.

a scenekit view runs update/render loop when knows there's animation going on. (because if there's no change in what's rendered, rendering wastes cpu/gpu time , eats battery power.)

scenekit rather conservative in guessing when should run render loop. runs if there caanimations or scnactions in scene or if physics engine doing something, think that's it.

if you've got other stuff wants run render loop (like overlay skscene needs run own game loop), set view's playing property true.