OpenXR VR

Requires feature: openxr

Nightshade supports VR headsets through the OpenXR standard using the Vulkan graphics backend.

Feature Flag

[dependencies]
nightshade = { version = "...", features = ["openxr"] }

This pulls in openxr, ash, wgpu-hal, and gpu-allocator dependencies and forces the Vulkan backend.

Launching in VR

Use launch_xr() instead of the normal application entry point:

#![allow(unused)]
fn main() {
launch_xr(MyState::default());
}

This initializes the OpenXR runtime, creates a VR session, and begins the render loop with stereo rendering.

XR Resources

Access VR state through world.resources.xr:

#![allow(unused)]
fn main() {
let xr = &world.resources.xr;
}

The XrResources struct provides:

Field	Description
`locomotion_enabled`	Enable/disable thumbstick locomotion
`locomotion_speed`	Movement speed multiplier

Controller Input

Read controller state through XrInput:

#![allow(unused)]
fn main() {
let input = &world.resources.xr.input;

if input.a_button_pressed() {
    // A button on right controller
}

if input.left_trigger_pressed() {
    // Left trigger
}

let left_pos = input.left_hand_position();
let left_rot = input.left_hand_rotation();
let head_pos = input.head_position();
}

Available Inputs

Method	Description
`left_trigger_pressed()` / `right_trigger_pressed()`	Trigger buttons
`left_grip_pressed()` / `right_grip_pressed()`	Grip buttons
`a_button_pressed()` / `b_button_pressed()`	Face buttons (right controller)
`x_button_pressed()` / `y_button_pressed()`	Face buttons (left controller)
`left_hand_position()` / `right_hand_position()`	Controller positions in world space
`left_hand_rotation()` / `right_hand_rotation()`	Controller orientations
`head_position()` / `head_rotation()`	Headset tracking
`left_thumbstick()` / `right_thumbstick()`	Thumbstick axes

The XrRenderer renders the scene twice per frame (once per eye) using the same render passes as the desktop renderer. View and projection matrices are provided by the OpenXR runtime through XrFrameContext.

Requirements

An OpenXR-compatible runtime must be installed (SteamVR, Oculus, etc.)
A VR headset must be connected
Vulkan GPU support is required
Desktop only (not available on WASM)

The engine configures Oculus Touch controller bindings by default.

Nightshade Game Engine