Kompakkt

Kompakkt is an open source browser viewer, annotation system and media repository for 3D models, point clouds and gaussian splats. It is maintained jointly by the Department of Digital Humanities at the University of Cologne and the Open Science Lab at TIB in Hannover, funded through NFDI4Culture, and it is positioned openly as the alternative for institutions that want to publish 3D collections without handing them to a commercial host. The hosted instance carried 848 published objects at the start of August 2026.

Splat support is merged, live and no longer experimental. The first splat code landed in April 2025 alongside a Babylon.js version bump and was labelled experimental at the time. A pull request merged in June 2026 added the parts that matter, and the project announced the capability publicly in July. Rendering is Babylon.js GaussianSplattingMesh rather than a custom renderer, and the Explore page carries a dedicated filter for 3D Gaussian splats.

SPZ is the delivery format and everything normalises to it. Upload accepts spz, splat and spx in the browser, and ply on the server, with a preprocessing service converting each to spz. Neither sog nor ksplat is supported anywhere in the codebase. Objects can also be registered by HTTPS URL rather than uploaded, so an institution can keep a splat on its own server and only index it in Kompakkt, and a standalone web component embeds the viewer on any site with no Kompakkt account at all.

The capability that separates Kompakkt from a viewer is annotation on the splat itself. Ordinary ray and mesh intersection does not work against a splat cloud, so the June change added a screen space picker that walks the raw splat position buffer to find the nearest splat under the cursor, along with a dialog to reposition an annotation afterward. Annotations attach to points in 3D space, group into collections and support collaboration, which is the workflow a museum or archive needs and a generic viewer does not provide. Museums have been an obvious application for radiance fields since well before splats were practical.

Running your own instance takes Docker, Docker Compose, Bun and Git, and brings up the repository, viewer, server, MongoDB, a Redis compatible cache, a search index and the conversion services together. Two things are worth knowing first. The orchestration repository describes itself as a development environment and there is no published production deployment guide, and the three repositories a self hoster most needs, covering orchestration, preprocessing and plugins, carry no licence file at all while the rest of the project is AGPL 3.0. The user documentation also still lists supported formats without mentioning splats or point clouds.