Open Source Fulldome Tilt Brush

Tilt Brush was just made open source by Google, so let's make it work in the dome!

##fulldome  #unity3d  #thanksgoogle 

  • One of my favorite apps for VR is Tilt Brush. It's fun to play with, and easy to pick up, even for first time VR users. I demo it all the time when I'm showing people VR tech for the first time.

    I am absolutely thrilled that Google has decided to make this project Open Source with an archived repository on github. Google doesn't stand to benefit much from the community by leaving their project archived, but anyone who wants to make a VR drawing program should have a look at it.

    Of course, my first objective was to build a fulldome version. For the proof of concept, I decided that adding a fisheye export stream to the user perspective would be easiest. Once I have that working, I can add a camera manipulation widget so the presenter can move the viewers around the scene. I think that an option to output equirectangular format video would also be useful.

    The first snag that I hit in the project is that the Unity version it's built in is old. It doesn't use a scriptable render pipeline so none of the newer fulldome cameras that I built will work with it, and the NDI tools package by Keijiro requires a newer version of Unity to work within. I tried upgrading the project to Unity 2020.x and it completely barfed. I plan on coming back to updating the project eventually, but I want some results now, so I searched through older versions of my own cameras and older versions of KlackNDI and found some that would work with the older Unity build.

    I had to go through and address some errors in the build processors to get the native Unity build tool to work, and then was able to produce a windows exe. There were some bugs in that which I had to take care of, like for some reason the controllers teleported to the South by a meter and kept themselves just out of reach.

    After importing the original scene and making my camera adjustments to it, I was able to produce a build of the game to upload here. This is license free, open source software you can download and use at your own risk. The first version includes no camera manipulation tools and the preview window is also original format. It live broadcasts an NDI fulldome formatted stream called DomeBrush that you can open on your display computers.

    If you're interested in building your own dome version of tilt-brush, I've created a public fork of the tilt-brush project to put my dome camera changes in. It's available at https://github.com/thebelin/tilt-brush/tree/feature-domecamera.

    Note that the project that I built produces an NDI video stream. To show the NDI stream on your planetarium, you will have to open it as a live video feed (h265). This is natively supported in Digistar 6+. You can also acquire the signal via the NDI Resolume plugin. NDI broadcasts over the network, so you can run the program on one computer and show it with another.