Class RuntimeScenePixiRenderer

In VR, only 3D elements can be rendered, 2D cannot. This rendering method skips over all 2D layers and elements, and simply renders the 3D content. This method is to be called by the XRSession's requestAnimationFrame for rendering to the headset whenever the headset requests the screen to be drawn. Note that while an XRSession is in progress, the regular requestAnimationFrame will be disabled. Make sure that whenever you enter an XRSession, you:

• Call this function first and foremost when the XRSession's requestAnimationFrame fires, as it is necessary to draw asap as the headset will eventually stop waiting and just draw the framebuffer as it is to maintain a constant screen refresh rate, which can be in the middle of or even before rendering if we aren't fast enough, leading to screen flashes and bugs.
• Call GDevelop's step function to give the scene a chance to step after having drawn to the screen to allow the game to actually progress, since GDevelop will no longer step by itself with requestAnimationFrame disabled.

Note to engine developers: threeRenderer.resetState() may NOT be called in this function, as WebXR modifies the WebGL state in a way that resetting it will cause an improper render that will lead to a black screen being displayed in VR mode.