Highlights

Rerun 0.36 brings 3D gaussian splats to the Viewer: log them from the SDK or open a PLY file directly, complete with anisotropic scale, opacity, and view-dependent color. The experimental Viewer catalog now streams .rrd files lazily in the browser, so the web Viewer can open recordings larger than your RAM. 3D views got configurable axes, the timeline got a new playhead navigation menu, and GrpcServerSink can finally be combined with other sinks, so you can serve live data and write a file at the same time.

Experimental 3D gaussian splat support

Rerun has now an experimental GaussianSplats3D archetype and supports visualizing them in the Viewer!

You can load any gaussian splat PLY file directly with the viewer or log the archetype directly from the logging SDK. The archetype supports anisotropic scale and rotation, opacity, and view-dependent color using spherical harmonics up to degree 3.

This support is experimental as the archetype and our renderer (which is kept very simple for now and is compatible with all browsers) may still evolve significantly.

Let us know which formats and splatting variants you would like us to support next!

Experimental Viewer catalog: larger-than-RAM files on the web

The experimental Viewer catalog can now load .rrd files lazily in the web Viewer. Files opened through the file dialog or drag-and-drop are streamed into the browser's Origin Private File System without passing through Wasm linear memory, and recording chunks are then read on demand. This lets the web Viewer open recordings larger than available RAM and even larger than Wasm's 4 GiB address space. Reopening the same file reuses its content-addressed browser-storage copy, when persistence is enabled.

Embedded default blueprints are now preserved when an .rrd is registered, so recordings open with their intended layout. The Viewer catalog also stays hidden in the recording panel until it contains data.

To try it, open Settings, then enable Load files via Viewer catalog under Experimental before opening the .rrd file. For large files on the web, also select Request persistence under Origin private filesystem. This asks the browser to protect Viewer catalog files from automatic storage eviction and may increase the storage quota in some browsers; the browser can still deny the request.

Configurable axes for 3D views

Previously, setting the up, left, and down directions of a 3D scene required logging ViewCoordinates at the scene root. You can now configure the axes directly from the UI or through blueprint code by changing the axes property.

Improved viewer timeline navigation

A new playhead navigation menu makes it easier to jump through a recording, and shows you what keyboard shortcuts are available.

Multi-sink support for GrpcServerSink

GrpcServerSink can now be combined with other recording sinks in the Rust, Python, and C++ SDKs. This makes it possible to stream data to connected Viewers while simultaneously writing the same recording elsewhere.

# Stream data to several sinks at once:
rr.set_sinks(
    # Host a gRPC proxy server that web Viewers can connect to:
    rr.GrpcServerSink(),
    # Write data to a `data.rrd` file in the current directory:
    rr.FileSink("data.rrd"),
)

See Multiple sinks for more information.

Better MCAP file introspection via CLI and Python

The rerun mcap info CLI command has been rewritten to output richer and more detailed file-level information instead of just diagnostic checks. The diagnostic checks are now in a dedicated rerun mcap check subcommand instead. For programmatic access, the same information can be now also accessed through McapReader.info() in Python:

reader = McapReader("data.mcap")

print(f"{reader.info().chunks.count} chunks at max. {reader.info().chunks.max_compressed_size_bytes} B")

if reader.info().metadata_count > 0:
    print("MCAP has metadata records")

for channel in reader.info().channels:
    print(f"{channel.topic} [{channel.schema.name}] - {channel.message_count}")

The info is lazily built & cached once, so repeated calls to info() are cheap.

Breaking changes

Entry-name restrictions now apply to application IDs

To unify application IDs and catalog entry names, the EntryName restrictions now also apply to ApplicationId. Rerun tries to migrate existing application IDs by replacing unsupported characters and dots with hyphens and adding a short hash suffix. Long application IDs are truncated and receive the same suffix.

Update application IDs to use at most 180 characters and only ASCII alphanumeric characters, underscores, hyphens, spaces, brackets, and colons. For example, change my/application to my-application.

ParquetReader loading options moved to stream()

The experimental ParquetReader's constructor now takes only the file path. All loading options (entity_path_prefix, column_grouping, delimiter, prefixes, use_structs, static_columns, index_columns) moved to stream():

# 0.35
ParquetReader(path, column_grouping="individual", index_columns=[IndexColumn.sequence("frame")]).stream()

# 0.36
ParquetReader(path).stream(column_grouping="individual", index_columns=[IndexColumn.sequence("frame")])

The reader is now a lightweight handle over the file, and each stream() call is independent — one reader can drive several differently-configured streams over the same file.

Looking for an older release? See the migration guides for 0.33 and earlier.