Rerun Adds an Experimental Gaussian Splat Archetype and EWA Renderer in 0.36.0

Rerun has released version 0.36.0, which adds an experimental GaussianSplats3D archetype and an EWA splat renderer to its Viewer. Rerun ingests multimodal data and their built-in viewer renders everything in sync, in realtime.

The archetype treats each gaussian as an anisotropic 3D distribution, a unit isotropic gaussian scaled per axis, then rotated and translated, with scales expressed as standard deviations along the principal axes in scene units.

Any gaussian splatting PLY file opens directly in the Viewer, and the archetype can also be logged from the Python, Rust and C++ SDKs. GaussianSplats3D requires centers as Position3D, recommends scales, quaternions and colors, and takes sh_coefficients and spherical_harmonics_degree as optional fields. View dependent color uses spherical harmonics up to degree 3, and Rerun's Python example carries 15 view dependent RGB coefficients covering degrees 1 to 3 per splat.

A robotics team already logging camera frames, poses and depth into a Rerun recording can now log the reconstructed splat into the same recording and scrub all of it on one timeline.

Unlike 3DGS training checkpoints, GaussianSplats3D stores values in their natural form, linear scales and base colors with opacity as RGBA. Splats can be shown in Spatial3DView and in DataframeView.

The renderer is an EWA splatting implementation in re_renderer, which Rerun describes as "kept very simple for now" and compatible with all browsers. Rerun labels the archetype unstable, warning that it may change significantly in a way that the data will not be backwards compatible. PLY is the only splat format the release names, and Rerun is asking which formats and splatting variants to support next.

The splat work arrives alongside an experimental Viewer catalog that streams .rrd files lazily in the browser, letting the web Viewer open recordings larger than available RAM and larger than Wasm's 4 GiB address space. Rerun 0.36.0 also adds configurable coordinate axes for 3D views, a playhead navigation menu on the timeline, and multi sink support for GrpcServerSink, so a recording can be served over gRPC and written to a file at once.

Rerun 0.36.0 installs with pip install -U rerun-sdk and cargo add rerun. It is available now through GitHub.