Raspberry Pi

The VR environment runs on a Raspberry Pi 4 Modell B located on the platform, running Raspbian 10 (Buster). The Pi is connected to the screens via micro HDMI cables. The Raspberry Pi is powered through one of the USB cables on the slip ring, using a USB to USB-C adaptor. Connections are indicated below

Figure 1. Connections to Raspberri Pi4

Sensor input through USB

The optical sensor inputs transformed on the Teensy to calculate the motor displacement are converted using the Mouse HID Library, and transmitted to the Pi via USB.

Godot

Compilation instructions

Godot 3.2 is compiled from source using clang.

After installing clang and any required libraries (see https://docs.godotengine.org/en/stable/development/compiling/compiling_for_x11.html), clone and install Godot using the commands below:

git clone https://github.com/godotengine/godot
cd godot
git checkout 3.2-stable
scons platform=x11 target=release_debug tools=yes use_llvm=yes CCFLAGS="-mtune=cortex-a72 -mcpu=cortex-a72 -mfloat-abi=hard -mfpu=neon-fp-armv8" -j4
sudo cp bin/godot.x11.opt.tools.32.llvm /usr/bin/godo

Environment

The 3D environment is created in Godot. The camera position is updated using a script written in GDScript, relative to the movements of the emulated mouse carrying the optical sensor input. The game is run via a bash script that ensures the game is running in full screen mode across the two monitors. The (x,y) coordinates of the player within the environment are automatically saved in a csv file.

The virtual corridor is available at https://github.com/atranvan/corridor