tchigher / simula

Linux VR Desktop

Simula is a VR window manager for Linux that runs on top of Godot. It takes less than 1 minute to install.

Video: Demonstration.

Compatibility: Currently, Simula is only compatible with SteamVR headsets equipped with Linux drivers (e.g. HTC Vive, HTC Vive Pro, & Valve Index).

Mission: Facilitate a Linux future for VR & AR Desktop. In the short-run, this means allowing people to run 2D Linux apps with current generation headsets. In the long-run, this means allowing people to run Linux in standalone AR & VR HMDs.

Origins: Simula is a reimplementation fork of motorcar. To read about motorcar, see Toward General Purpose 3D User Interfaces: Extending Windowing Systems to Three Dimensions

Text Quality

A common objection to the viability of VR Desktop is that it exhibits poor text quality; however, with our low pass filter, Simula has taken special care to make text quality as clear as possible:

The left image is a VR terminal without our filter applied; the right is the same image with our filter applied. Compared to other VR Desktops, Simula allows for significantly longer sessions without uncomfortable eye strain.

Installation

To install Simula on all Linux distros, run:

# Clone
git clone --recursive https://github.com/SimulaVR/Simula
cd Simula

# Download (or build, if downloading fails)
source ./utils/Helpers.sh && installSimula

# Launch
./result/bin/simula # Needs SteamVR to be running

Installing Simula should take less than 1 minute: this script doesn’t actually compile anything on your system, but instead downloads the appropriate binaries from our cache in a way that is system and driver agnostic. Under the hood, we (i) check whether you have nix and cachix installed (and, if not, install them); (ii) check which graphics drivers you have and (iii) download Simula via cachix with the appropriate driver flags, falling back to a nix build if downloading fails.

On NixOS systems, you must ensure

nix.trustedUsers = [ "root" "<your_user_name>"];

is added to your configuration.nix, or the install command above will be unable to download Simula from our cache, instead falling back to a manual build (which takes 1hr+).

Usage

Mouse & Keyboard Controls

Windows become “active” once you look at them. Active windows receive typing events from the keyboard, and cursor events from mouse movement. In addition, the following window-manipulation shortcuts are hard-coded into Simula (we’re going to make this customizable in the near future):

Key binding.	Action
Super + Escape	Toggle Simula’s mouse & keyboard grab (see below).
Super + /	Quick launch terminal
Super + Apostrophe	Send window cursor to gaze point (hold down to make cursor follow gaze)
Super + Enter	Left click surface cursor at gaze point
Super + Alt	Grab surface for movement (release to let go)
Super + f	Orient window towards user gaze
Super + 9	Scale window to smaller size
Super + 0	Scale window to larger size
Super + -	Increase window resolution (“zoom out”)
Super + =	Increase window resolution (“zoom in”)
Super + Comma	Move window towards you
Super + Period	Move window away from you
Super + Backspace	Kill surface being looked at
Super + k	Quick launch firefox
Super + g	Quick launch google-chrome
Super + w	Launch headset webcam view

NOTE: In order to prevent Simula’s keyboard shortcuts from conflicting with your existing window manager’s shortcuts, Simula “grabs” the system keyboard and cursor to prevent input events from propagating past Simula. This creates a problem: it is then impossible for you to escape Simula once you launch it! In order to get around this, press Super + Escape to ungrab Simula, which will restore mouse and keyboard control to your normal window manager.

VR Controllers

• Left-clicking. Use (7) gently (you don’t have to go all the way down to click).
• Right-clicking. Use (1).
• Scrolling. Scroll up and down via (2).
• Text dragging. Hold (7) down and drag.
• Window manipulation. Point at a window and, while holding (8), move your controller around. The windows should “levitate” in the direction of your movement.
• Window rescaling. Point at a window, hold (8) down, and then scroll up and down on (2).

Mouse & Keyboard View

Simula has a headset webcam view (binded presently to Super + w) that allows you to see your mouse and keyboard from VR.

Community

For troubleshooting and discussion, join our community at https://discordapp.com/invite/a4PnP7n.