Open Blocks is an intuitive low-poly 3D modeling application for VR. It is a fork of Blocks by Google, which was made open source in 2024. Now, the Icosa Foundation maintains and steadily improves Open Blocks, backed by a community of committed developers, creators, and artists.

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Open Blocks Early Access was released on the Meta Quest store at the end of January 2025. 

If you have a Quest 2 or 3, check it out! :)

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Blocks was originally developed for PCVR. Our role has been to update Open Blocks to work on modern standalone VR devices and help get it ready for release. With the new OpenXR standard, applications can run on a variety of XR devices from PCVR to standalone without the need to implement platform-specific solutions.

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Many things did not work straight away when building Open Blocks for Quest. Shadows weren't rendering correctly due to the difference in graphics APIs (Quest uses Vulkan, whereas PCVR initially used DirectX). The problem was that Unity treats low-precision data types differently, depending on the graphics API. DirectX uses high-precision data types regardless of what data type is specified in the shader whereas Vulkan actually tries to use the data type specified.

 

Another blocking issue was the fact that the original Blocks had memory leaks. On PCVR, users usually have large amounts of RAM available, and likely the leaks won't cause any issues when doing moderate modelling. But the Quest 2 and 3 only have 6 and 8 GB respectively of which some proportion is reserved for the operating system. The cause of the leaks was the creation of temporary meshes whenever the user was interacting with their 3D model in the scene, moving it around or changing its color or shape. These temporary meshes never got deleted and used up the available memory until Blocks eventually crashed. We successfully removed the memory leaks and put some warnings in place so users are aware of the current limits.

 

In general, standalone VR devices are extremely constrained by performance. A lot of work is currently going into optimizing Open Blocks so it runs more smoothly. The original Blocks used custom shaders and shadows which are very very performance intensive and result in low framerates on standalone headsets. We are currently replacing the custom shaders with Unity's Universal Render Pipeline (URP) which should greatly increase the framerate.

 

Open Blocks has a huge code base and there is still a lot to do to improve and extend the current functionalities. We are happy to help with as much as we can!

 

In any case, Open Blocks is already an amazing tool and great for creators of all skill levels, so if you have a minute, it is absolutely worth trying!