viser4d 0.17.2

A viser extension with out-of-the-box support for the time dimension

viser4d

viser4d is a small extension of viser for recorded 3D scenes with a time dimension.

Features include:

• Record scene updates across discrete timesteps with with server.at(t):.
• Play, pause, scrub, and step through the timeline directly in the browser.
• Stream long recordings in chunks and preload nearby timeline blocks for responsive scrubbing.
• Keep playback client-local so different browser tabs can explore the same recording independently.
• Attach timeline-synced audio tracks.
• Export recordings as .viser files or standalone HTML.

The goal is to keep viser's live scene API while adding a separate recorded timeline API for playback and export.

Chunking is controlled by viser4d.ChunkStreamingConfig. By default, Viser4dServer populates it from VISER4D_BLOCK_SIZE and VISER4D_CLIENT_CHUNK_CACHE_SIZE, falling back to 32 steps per block and a 1GB per-client preload budget. You can also pass chunk_streaming=viser4d.ChunkStreamingConfig(...) for one server instance.

Installation

You can install viser4d with pip:

pip install viser4d

Quickstart

import numpy as np
import viser4d

server = viser4d.Viser4dServer(num_steps=10, fps=10)

server.scene.add_frame("/origin", axes_length=0.25)
server.scene.add_grid("/ground", width=10.0, height=10.0)

point_cloud = None
for t in range(10):
    with server.at(t) as timeline:
        points = np.random.uniform(-1.0, 1.0, size=(200, 3))
        if point_cloud is None:
            point_cloud = timeline.scene.add_point_cloud(
                "/points",
                points=points,
                colors=(255, 200, 0),
            )
        else:
            point_cloud.points = points

server.sleep_forever()

Open the viewer in your browser and use the built-in Playback controls to play, pause, scrub, and step through the recorded timeline.

Outside server.at(t), server.scene behaves like normal viser. Inside server.at(t), writes to timeline.scene and timeline.audio are recorded into the timeline.

More Examples

• Hello world
• Camera path
• Multiple timestep batch
• Timeline-synced audio
• Heavy scene stress test

Export

blob = server.serialize()
html = server.as_html()

Use server.serialize() to export a .viser recording and server.as_html() to export a self-contained HTML viewer.