Thursday, February 24th, 2022 Posted by Jim Thacker

Download free virtual reality 3D sketching app Open Brush

Icosa Gallery has released Open Brush 1.0, a promising new open-source virtual reality 3D sketching app.

The software, forked from the formerly Google-developed Tilt Brush, lets users paint in 3D space using an Oculus or SteamVR-compatible headset, and export the resulting 3D sketches in FBX, glTF or USD format.

A community-run open-source successor for former Google VR projects
Open Brush is based on Tilt Brush, the room-scale 3D painting and sketching tool previously developed by Google, and made open-source in 2021 following its decision to stop developing it as a commercial product.

It is the second VR project that Icosa Gallery has taken over from Google: the site was originally launched as a community-run replacement for Poly, Google’s now-defunct platform for sharing low-poly 3D assets.

Paint in virtual reality and export the 3D sketches to DCC applications or game engines
Like its predecessor, Open Brush enables artists to paint coloured strokes in virtual reality that function both as paint strokes and 3D geometry.

Users can control the form of each stroke by curving or lathing it, and it is possible to constrain strokes to straight lines or use grid or angle snapping to sketch geometric as well as organic objects.

Once created, strokes can be mirrored, recoloured or erased, and users can set up lights, cameras and a background environment for the resulting 3D sketch.

Completed sketches can be published to the Icosa Gallery itself, or exported in glTF, FBX, USD or JSON format, making it possible to use them as concept designs that can be refined in apps like Blender or Maya.

Sketches can also be used directly as VR assets in game engines: Open Brush has a dedicated Unity SDK.

It’s also possible to render video of a 3D sketch: you can upload to YouTube directly from Open Brush.

As well as painting in virtual reality, users can run the software in monoscopic mode on Windows or Mac. It’s described as “clunky in places”, but is currently the only way to use Open Brush on macOS.

New in Open Brush 1.0: automatic smoothing of freehand strokes, plus the option to merge 3D sketches
As well as being a free product – only the source code of Tilt Brush is free: users still have to pay for compiled binaries – Open Brush adds a longish list of new features to the software.

Key changes include Lazy Input, automatically smoothing freehand strokes in a similar way as ZBrush’s Lazy Mouse system, colour jitter for paint strokes, and the option to merge sketches.

Open Brush 1.1, due out in beta in “a few weeks” will add a layer system and a Snip Tool for cutting and deleting parts of existing strokes.

Licensing and system requirements
Open Brush 1.0 is available free on Windows, Linux and macOS. To use it in VR mode, you will need an Oculus or SteamVR-compatible headset, which includes HTC Vive and Windows Mixed Reality headsets.

The source code is available under an Apache 2.0 licence.

Read more about Open Brush in the online documentation

Download compiled builds of Open Brush

Download the source code for Open Brush from Icosa Gallery’s GitHub repository