# Playing 3D Movie in VisionPro and Quest 3

This example shows how to use background images + layers
to play a 3D movie in the VisionPro and the Quest 3

Before you start, first run the following script:

```shell
# From the Mary Project: https://www.meryproject.com/
# 360 Stereo from http://pedrofe.com/rendering-for-oculus-rift-with-arnold/
wget -O mary.webm https://threejs.org/examples/textures/MaryOculus.webm
```

![Side view of the 3D movie screen](figures/21_3D_movie.png)


> **ImagePlane.layer Property**
>
> The underlying rendering engine supported a layer binary bitmask
> for both objects and the camera. Below we set the two image planes,
> left and right, to `layers=1` and `layers=2`. Note that these two 
> masks are associated with left eye's camera and the right eye's
> camera.



```python
from asyncio import sleep

import imageio as iio
from tqdm import tqdm

from vuer import Vuer
from vuer.events import ClientEvent
from vuer.schemas import Scene, ImageBackground

reader = iio.get_reader("./mary.webm")

app = Vuer()

# we add the handler here because the spawn(start=True) binding is blocking.
@app.add_handler("CAMERA_MOVE")
async def on_camera(event: ClientEvent, session):
    assert event == "CAMERA_MOVE", "the event type should be correct"
    print("camera event", event.etype, event.value)

@app.spawn(start=True)
async def show_heatmap(session):
    session.set @ Scene()

    while True:
        for i, frame in tqdm(enumerate(reader), desc="playing video"):
            # use the upsert(..., to="bgChildren") syntax, so it is in global frame.
            session.upsert(
                [
                    ImageBackground(
                        # We slice the left side of the stereo video
                        frame[::, :1024, :],
                        aspect=1.778,
                        height=1,
                        distanceToCamera=1,
                        layers=1,
                        # One of ['b64png', 'png', 'b64jpeg', 'jpeg']
                        format="jpeg",
                        quality=90,
                        key="background-left",
                        interpolate=True,
                    ),
                    ImageBackground(
                        # We slice the right side of the stereo video
                        frame[::, 1024:, :],
                        aspect=1.778,
                        height=1,
                        distanceToCamera=1,
                        layers=2,
                        # One of ['b64png', 'png', 'b64jpeg', 'jpeg']
                        format="jpeg",
                        quality=90,
                        key="background-right",
                        interpolate=True,
                    ),
                ],
                to="bgChildren",
            )
            # 'jpeg' encoding should give you about 30fps with a 16ms wait in-between.
            await sleep(0.016 * 2)
```