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Icosa Foundation: 2022–2026
Published on August 28, 2026 by Andy Baker
 

Four years of open 3D creation, preservation and growth


It’s been a while. Our last substantial Open Collective update was published at the start of 2022. At that point, Open Brush 1.0 had just shipped, Icosa Gallery was mostly a promise to replace the parts of Google Poly that the community had lost, and Google Blocks was still a closed-source application that had not been updated for years.

A great deal has happened since then. Many of the goals on that old page have become features we’ve shipped, running services, or the foundation for much larger projects. Icosa has grown from a rescue effort around a handful of discontinued Google VR tools into a broader, free and open-source ecosystem for creating, sharing, and preserving immersive 3D work.

From conservation to ecosystem


Icosa started with a very immediate problem: Google Poly was closing, taking with it a major public home for work made in Tilt Brush and Blocks. The early mission was one of preservation: keep the work accessible and the tools usable, while making sure artists were not trapped by the decisions of a single platform owner.

Today, that mission has expanded. We maintain Open Brush, Open Blocks and Icosa Gallery, alongside libraries, viewers and integrations that connect those projects via the web, Unity, Blender, Godot and other tools. We have also begun restoring and extending the open-source IMM format and player used for Quill immersive animation.

We believe that creative tools and creative work should not disappear just because a company changes direction. When we, as a community, can preserve source code and formats, we can keep them usable. And then we can keep pushing them forward.

Open Brush: maturing into a platform


When we last wrote here, Open Brush had reached 1.0 and represented a stable build of the erstwhile Tilt Brush. It has come a long way since.

One of the biggest pieces of work was the move to a modern Unity and OpenXR foundation.Open Brush 2.0 was the result of a substantial upgrade effort and brought the project onto the XR standards that current headsets and runtimes are built around. That work unlocked broader hardware support and created room for features such as passthrough, layers, snipping and joining strokes, pressure-sensitive painting, improved camera tools and a much wider range of import options.

The application has kept evolving from there. Our precision workflows gained tools such as axis locking, alignment and the Transform panel. We expanded Import and export to support a broad range of 2d and 3d file types. We brought features to standalone headsets that had previously been desktop-only. We made non-VR viewing more useful, so sketches can be explored on ordinary computers and mobile devices as well as headsets. We built a brand-new multiplayer mode.

The biggest change, though, may be extensibility. Open Brush can now be controlled through HTTP and WebSocket APIs, allowing external scripts and applications to create or manipulate sketches. More recently, we added Lua plugin scripting, which has made it possible to change painting behaviour interactively, create new tools, build new symmetry modes and experiment with completely different ways of drawing without compiling a custom version of Open Brush. This allows Open Brush to be extended, customised and integrated without needing to be a professional programmer.

Open Brush now also connects directly to the rest of the Icosa ecosystem. Users can browse and publish through Icosa Gallery, import models created in Open Blocks, work with formats such as GLTF, OBJ, VOX and SVG, save reusable groups of editable strokes and move work into other tools more reliably.

This work marks an important shift in how we think about the project. We have succeed in resurrecting Tilt Brush from the moment Google stopped developing it. Our goal now is to keep the qualities people loved about Tilt Brush while allowing Open Brush to become its own extensible and interoperable creative platform.

Icosa Gallery: from Poly replacement to open infrastructure


Icosa Gallery began as the answer to one very specific question: where should the community's 3D work live after Google Poly? It’s now becoming something broader.

Our official Gallery instance is live, and we have restored as much public Poly content as we have been able to recover, building on preservation work carried out by Archive Team volunteers and the Internet Archive. This is important in its own right: a huge amount of early VR and 3D-native creative history would otherwise be much harder to discover or experience.

But preservation is only one half of the Icosa Gallery. The software is open source, designed to be self-hosted and customised, and exposes a documented API so that the content does not have to remain locked inside a single proprietary website.

Since the project’s inception, we have been building the connective tissue of the ecosystem around this API. For example, browsing and publishing work is integrated directly into Open Brush and Open Blocks. The web viewer and supporting libraries can be reused outside the Gallery in artists’ and archivists’ own projects. There is a Unity toolkit for browsing and importing assets at edit time or runtime, a Blender plugin, a Godot addon, and ongoing work to make Gallery content useful in other open platforms and workflows.

This interoperability work has been supported by external funding as well as community contributions. An NGI0 Entrust grant through NLnet supported major Gallery development from 2023 to 2025. A follow-up NGI0 Commons project is focused on improving format conversion, reusable Gallery components and workflows with tools including Blender and Godot.

This is why we increasingly describe Icosa Gallery as infrastructure rather than just a website. The aim is to maintain an open place to publish and preserve 3D content, supported by a set of APIs, viewers, importers and tools that make that content useful wherever people actually create and build.

Open Blocks joins the family


One of the happiest surprises of the last few years was Google Blocks finally becoming open source.

We had asked about the possibility around the time Tilt Brush was released, but at that point it couldn’t happen. In 2024 we tried again, reaching out to people from the original Blocks team. That effort helped get the conversation moving, and Google released the Blocks source in 2024, explicitly pointing to Icosa Foundation and the work already done with Open Brush.

We immediately started Open Blocks, a community-led continuation of the original application. The first priority was to make the old VR codebase viable on modern hardware, moving it towards OpenXR, a modern input system and offering standalone builds for devices such as Quest and PC VR.

Since then the project has started to move beyond restoration. We’ve implemented publishing to Icosa Gallery, CSG operations, improved authentication, OBJ and GLTF import, VOX import, and experimental modelling features such as loop subdivision and deletion of individual edges, faces and vertices.

Bringing Open Blocks into our collection also closes a loop we had thought about for years. You can create a model in an intuitive immersive modelling tool, share it through Icosa Gallery, bring it into Open Brush, and then continue using the same asset through Unity, Blender, Godot and the web. Each project is useful on its own, but they become much more interesting when they are allowed to talk to one another.

IMM and Quill: preserving immersive animation


Our newest major preservation project pushes our idea beyond the original Google ecosystem.

We are restoring and expanding IMM, the open-source immersive media format and reference playback engine used for Quill animation. IMM was designed for something ordinary video cannot do: keep an immersive work genuinely three-dimensional until the moment it is rendered. Its scene graph and timeline can combine animated 3D strokes, models, images, panoramas, audio and other media in a compact, streamable format. That format has real cultural value. IMM was used to deliver works including Rebels, the Tale of Soda Island series, The Remedy, Goodbye Mr. Octopus and other immersive films. 

Preserving the format and player therefore means preserving the ability to experience a body of work that was created specifically for six-degrees-of-freedom viewing.

The first unglamorous but important part of our work has been to make the original code reproducible again. Some of the project’s dependencies have disappeared from their original locations, so we started the Icosa Mirror project to vendor and record them, creating a dependable reference build for the future.

Moving beyond this, current work includes implementing modernised playback, Unity packages, Godot integration and XR sample projects, with platform work spanning desktop and standalone/mobile targets. The longer-term opportunity is exciting: IMM can become a useful open playback and interchange layer for immersive work, saving it from remaining a historical curiosity.

For us, this project is a natural extension of the Icosa Foundation’s mission. Preserving creative software is only part of the problem; we need to preserve the formats, runtimes and knowledge required to experience the work people have made with it.

What funding has allowed us to do


A large amount of Icosa development is still volunteer-led, but open source software is not free to operate.

Community contributions help cover Gallery hosting and storage, software and store fees, infrastructure, bug bounties and paid development work when a task needs sustained attention. These contributions also give us the flexibility to deal with maintenance work that is essential but rarely exciting enough to attract a dedicated grant.

External grants have allowed us to take on deeper infrastructure projects, particularly around Icosa Gallery and interoperability. Community funding and grant funding complement each other: one helps keep the lights on and the projects healthy, while the other can make larger development pushes possible.

If you have contributed through Open Collective over the past few years, you can rest assured your support has helped keep servers running, software shipping, bugs getting fixed. You have directly contributed to making old creative work accessible again, and you’ve helped provide new, open tools for people to expand on that body of work.

Where we are heading


Looking forward, our priorities are to:

  • keep Open Brush and Open Blocks current on modern XR hardware while expanding their creative capabilities;
  • make Icosa Gallery easier to self-host, integrate and reuse wherever you like;
  • improve movement of assets between immersive tools, the web, game engines and desktop creation software;
  • keep investing in scripting, plugins and APIs so that other developers and artists can extend the ecosystem without waiting for us;
  • preserve important immersive formats and runtimes such as IMM while finding new uses for them on current platforms.
  • new features for Open Brush such as Gaussian Splat import, animation, custom brushes, SDF Guides, brush strokes that can vary in color across their length, text and audio widgets, reshaping tools and more
  • new features for Open Blocks including procedural shapes, texture mapping, face smoothing and more editing tools

The thread running through all of this is interoperability. We want open 3D work to remain editable, portable and viewable. We want creators to be able to choose their tools and hosting. And we want projects to survive changes in hardware vendors, stores and corporate priorities.

Thank you


None of this has been solely the work of one team. Icosa exists because of the continued efforts of many developers, artists, testers, documenters, translators, archivists, bug reporters and donors.

Thank you to everyone who has contributed code, money, art, feedback, infrastructure, preservation work or time. Thank you as well to the original teams behind Tilt Brush, Blocks, Poly, Quill and IMM for making work that was worth preserving and, where possible, for helping put that work into the hands of the community.

We started by trying to prevent the disappearance of useful things. Four years later, the more interesting part is what the community has been able to build once those things were made open.

If you would like to help, you can support Icosa through Open Collective, contribute on GitHub, join the community on Discord, or simply use the projects and tell us what should be better.

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