Async Programming 101

This tutorial shows you how to write parallel routines/handle callbacks using async programming in vuer. We start by instantiating a vuer server.

from asyncio import sleep
import numpy as np

from vuer import Vuer
from vuer.schemas import Box

from vuer import VuerSession

app = Vuer(
    # These query parameters show up in the URL, and are used to configure the scene.
    queries=dict(
        reconnect=True,
        collapseMenu=True,
    ),
)

async def background_task():
    print("Hello from the background task!")
    await sleep(1.0)

async def long_running_bg_task():
    while True:
        print("Hello from the long running task!")
        await sleep(1.0)

T = 60


# use `start=True` to start the app immediately
@app.spawn(start=True)
async def main_function(sess: VuerSession):

    print("start background tasks")

    task = sess.spawn_task(background_task())
    task_long = sess.spawn_task(long_running_bg_task())

    t = 0

    while True:
        print("Hello from the main function!\r", end="")

        sess.upsert @ Box(
            args=[0.1, 0.1, 0.1],
            position=[np.sin(np.pi * t / T), 0, np.cos(np.pi * t / T)],
            rotation=[-3.14 / 2, 0, 0],
            materialType="physical",
            material=dict(
                color="red",
                roughness=0.0,
            ),
            key="box",
        )

        await sleep(1 / T)
        t += 1

        if t / T == 10:
            print("cancel background task")
            task_long.cancel()