Streaming FURY with user interaction

In this tutorial, we show how to use the FURY Streaming system to serve an interactive visualization through a web browser.

You can choose between two different encodings: WebRTC or MJPEG. WebRTC is a more robust option and can be used to perform a live streaming with a low-latency connection for example using ngrok. However, to use webRTC you need to install the aiortc library.

pip install aiortc

Notes

If you don’t have ffmpeg installed, you need to install it to use WebRTC

Linux

apt install libavdevice-dev libavfilter-dev libopus-dev libvpx-dev pkg-config

OS X

brew install ffmpeg opus libvpx pkg-config

import multiprocessing
import sys

import numpy as np

import fury

# if this example it's not working for you and you're using MacOs
# uncomment the following line
# multiprocessing.set_start_method('spawn')

if __name__ == "__main__":
    interactive = False
    # `use_raw_array` is a flag to tell the server to use python RawArray
    # instead of SharedMemory which is a new feature in python 3.8
    # https://docs.python.org/3/library/multiprocessing.html#multiprocessing.Array
    # https://docs.python.org/3/library/multiprocessing.html#shared-memory-objects

    use_raw_array = sys.version_info < (3, 8)
    window_size = (300, 300)
    # `max_window_size` are the maximum size of the window that will be
    # allowed to be sent to the browser. For example, if you set
    # `max_window_size=(800, 800)` then the browser will be limited to
    # a window of size (800, 800).

    max_window_size = (400, 400)
    # 0 ms_stream means that the frame will be sent to the server
    # right after the rendering

    # `ms_interaction` is the time in milliseconds that the user will have
    # to interact with the visualization

    ms_interaction = 1
    # `ms_stream` is the number of milliseconds that the server will
    # wait before sending a new frame to the browser. If `ms_stream=0`
    # then the server will send the frame right after the rendering.

    ms_stream = 0
    # max number of interactions to be stored inside the queue
    max_queue_size = 17
    ######################################################################
    centers = np.array([[0, 0, 0], [-1, 0, 0], [1, 0, 0]])
    colors = np.array([[1, 0, 0], [0, 1, 0], [0, 0, 1]])

    actors = fury.actor.sphere(centers, opacity=0.5, radii=0.4, colors=colors)
    scene = fury.window.Scene()

    scene.add(actors)

    showm = fury.window.ShowManager(scene=scene, size=(window_size[0], window_size[1]))

    stream = fury.stream.FuryStreamClient(
        showm, max_window_size=max_window_size, use_raw_array=use_raw_array
    )
    stream_interaction = fury.stream.client.FuryStreamInteraction(
        showm, max_queue_size=max_queue_size, use_raw_array=use_raw_array
    )

    if use_raw_array:
        p = multiprocessing.Process(
            target=fury.stream.server.web_server_raw_array,
            args=(
                stream.img_manager.image_buffers,
                stream.img_manager.info_buffer,
                stream_interaction.circular_queue.head_tail_buffer,
                stream_interaction.circular_queue.buffer._buffer,
                8000,
                "localhost",
                True,
                fury.stream.server.main.WEBRTC_AVAILABLE,
            ),
        )

    else:
        p = multiprocessing.Process(
            target=fury.stream.server.web_server,
            args=(
                stream.img_manager.image_buffer_names,
                stream.img_manager.info_buffer_name,
                stream_interaction.circular_queue.head_tail_buffer_name,
                stream_interaction.circular_queue.buffer.buffer_name,
                8000,
                "localhost",
                True,
                fury.stream.server.main.WEBRTC_AVAILABLE,
            ),
        )
    p.start()
    stream_interaction.start(ms=ms_interaction)
    stream.start(
        ms=ms_stream,
    )
    ###########################################################################
    # If you have aiortc in your system, you can see your live streaming
    # through the following url: htttp://localhost:8000/?encoding=webrtc
    # Other wise, you can use the following url:
    # http://localhost:8000/?encoding=mjpeg

    if interactive:
        showm.start()

    # We need to close the server after the show is over
    p.kill()
    ###########################################################################
    # We release the resources and stop the interactive mode
    stream.stop()
    stream_interaction.stop()
    stream.cleanup()
    stream_interaction.cleanup()

    fury.window.record(
        scene=showm.scene, size=window_size, out_path="viz_interaction.png"
    )