InstanceBrick--nightcap/docs/SETTINGS.md

Settings

Video

Open the game's SteamVR Video settings after installing the settings integration.

The standard profile is native 2160 × 2160 per eye, 72 Hz, SMAA High and Performance foveated rendering. The application targets 72 FPS at 72 Hz; actual frame rate depends on the experience and Roblox's graphics settings. The gaze radius remains adjustable, and existing saved choices are preserved.

Setting	Effect
Foveated Rendering	Off uses full-density shading throughout. Quality, Balanced and Performance progressively reduce peripheral shading work. Each mode keeps the same full-detail gaze region.
Gaze sharp radius	Sets the minimum full-detail region around your gaze, from 8% to 35%. Larger values preserve more of the view at full density and cost more GPU time. Hardware tile boundaries can enlarge this region.
Anti Aliasing	Off, FXAA, SMAA Low or SMAA High. Filtering runs around your gaze on the composed eye image, including interface edges. SMAA High is the default.
Desktop Mirror	Off by default on Frame. On displays the VR image in the desktop window as well as the headset. Relaunch Nightcap after changing it.
Performance Overlay	Shows actual game FPS, headset Hz, average frame time, SteamVR GPU time and per-eye resolution at the bottom center of the headset view. It hides while the Steam menu is open and does not capture controller input.
Resolution Per Eye	Sets the headset eye-buffer size. Nightcap's recommended default is 2160 × 2160 per eye; Auto and Reset to Defaults use this baseline. Explicit custom values stay selected. Changes apply after the slider settles, with a brief pause while eye buffers are rebuilt at a safe frame boundary.
Display Refresh Rate	The standard profile uses 72 Hz. The launcher follows the selected per-game headset rate and any explicit Steam frame limit. Restart Nightcap after changing the rate or frame limit so Roblox's internal cap matches it.

Enable Performance Overlay, then close the Steam menu. APP FPS counts new Roblox projections over a rolling second. HMD Hz is the headset refresh rate. FRAME is average time per submitted game frame, TARGET is the configured application frame rate, and BUDGET is the time available per application frame: 13.89 ms for 72 FPS at 72 Hz. Repeated or reprojected compositor frames do not count as new game frames.

GPU averages SteamVR timings for new application frames, excluding compositor-only reprojections. It can include scheduling gaps. The overlay reports standby or missing frames instead of retaining a stale FPS. Its setting persists between launches and can be turned off at any time.

Foveated rendering reduces fragment-shader work in the 3D scene before the image is composed. The final composition stays at native resolution, keeping screen-space text and interface elements from being coarsened a second time. Your gaze region retains the detail available at the selected eye resolution; the periphery uses progressively lower shading density.

Foveation, gaze radius and anti-aliasing controls update while the application is running. Higher eye resolutions improve fine detail and increase GPU and memory cost. For more headroom, keep Performance foveation, reduce the gaze radius if needed, or lower Roblox's own graphics quality.

The launcher uses the selected Steam Video resolution without an extra multiplier. To add supersampling, set NIGHTCAP_VR_RENDER_SCALE when launching Nightcap; for example, NIGHTCAP_VR_RENDER_SCALE=1.25. The default is 1.0. Larger values increase GPU work.

The launcher reads the selected headset refresh rate and SteamVR's frame limit on every launch. At 72 Hz with no frame limit, Roblox's internal scheduler is capped at 72 FPS. Half-rate rendering is not forced automatically.

On Frame, the render thread prefers higher-capacity cores within the CPU allocation supplied by SteamVR. To use the default thread placement, launch with NIGHTCAP_VR_PREFER_PERFORMANCE_CORES=0.

Controllers and typing

The native VR bridge supplies controller tracking, buttons, axes and haptics. Roblox experiences choose how to use those inputs. The in-headset keyboard opens when a text field receives focus; point at a key and pull the trigger to type. Steam Controller desktop navigation can also be configured through the Steam shortcut's controller layout.

Microphone

Set the Frame's headset microphone as the default input in the desktop audio settings and check that it is not muted. Roblox voice chat uses its normal account eligibility, microphone permission and in-experience controls.

Nightcap's native recording bridge captures the selected input when Roblox requests recording. To choose a different input, close Nightcap and edit ~/.local/share/nightcap-vr-arm64/data/.config/mocktail/config.yaml:

audio:
  input_device: default

An exact SDL device name can replace default. Input device names appear in the launch log.

Desktop mirror

Open SteamVR's per-game Video settings and set Desktop Mirror to On to show the VR view in a desktop window. Set it to Off to keep the Frame's single headset application without the extra desktop view. Relaunch Nightcap after changing this setting. The Frame default is Off.

The Frame launcher reads the saved SteamVR mirror choice and coordinates both the mirror renderer and desktop-window visibility. This setting takes precedence over the YAML value when using the Frame launcher. Generic Nightcap launches can configure the mirror beside the VR option:

vr:
  enabled: true
  desktop_mirror: true

MOCKTAIL_VR_DESKTOP_MIRROR=1 or 0 overrides the YAML setting for generic launches. VR and desktop mirroring are separate options; enabling VR does not require the desktop mirror.

Roblox's desktop viewport stays at 1920 × 1080 during VR for stable in-game menu size, independently of headset eye resolution. On Frame, desktop window geometry is not restored or saved in VR, including when the mirror is enabled.

Files and troubleshooting

Item	Location
Launcher	~/.local/bin/nightcap-vr-arm64
Launch log	~/.local/share/nightcap-vr-arm64/last-launch.log
Configuration	~/.local/share/nightcap-vr-arm64/data/.config/mocktail/config.yaml
Local client store	~/.local/share/nightcap-vr-arm64/data/.local/share/mocktail
Steam shortcut identity	~/.local/share/nightcap-vr-arm64/steam-shortcut.json

If launching fails, check the launch log, make sure SteamVR is running and confirm that the localhost/nightcap-vr-arm64:frame-foveated image exists. If the game reports an unsupported client, update Nightcap before replacing the client. Keep account data and client downloads outside source control.