On the Steam Frame a layer inside SteamVR's compositor draws the home where it would draw Aurora, so the home is the
environment itself: at boot, during game loads, behind the Steam menu, with the controllers and passthrough, and it
steps aside for a game the instant it opens. On a PC this was faked with SteamVR's home-app slot and a flat 360 photo
in the gaps, which launched and handed off like an app and showed a picture, not the live home. This does it properly
on any PC that runs SteamVR, the Frame's way:
- Windows: the compositor is Direct3D 11, so the layer is a proxy d3d11.dll beside the compositor (layer/
frame_home_layer_d3d11.cpp, built from the .def that forwards every other export to the real d3d11.dll, kept as
fh_d3d11real.dll). It wraps the compositor's device, finds Aurora's draws by their shader bytecode and draws the
home over the sky, leaving the floor and stars off; everything else passes straight through. Pure pass-through in
any process that isn't vrcompositor.
- The home's frames cross from Frame Home (Vulkan) to the compositor (D3D11): the layer owns kSlots shared textures
and hands Frame Home their NT handles over a named pipe; Frame Home imports them (VK_KHR_external_memory_win32) and
renders into them. No cross-API lock — a slot is published only once the GPU has finished it and the four rotate,
as on Linux. The shared State stays Frame Home's.
- The Environments panel runs frame-home --system and keeps it alive (one at a time, a pid file across panel
restarts), the same systemEnv path as the Frame. The installer places/removes the proxy and marks the layer with a
root/layer folder, in place of the old home-app registration and background pictures.
- Safe like the Vulkan layer: no home, or one stale over half a second, and the compositor draws Aurora as usual;
the layer turns itself off after two unhealthy compositor starts, and root/layer/off turns it off by hand.
Linux keeps its Vulkan layer (unchanged). Verified without a headset on the null driver: the proxy loads and wraps
the compositor without crashing, recognises Aurora's shaders, and the frame hand-over completes (Frame Home connects,
imports the textures, renders). The compositor only draws the environment while presenting to a headset, so the final
on-headset image is the one step the null driver can't exercise.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
- frame-home --install/--uninstall and frame-switcher --install/--uninstall check for SteamVR's server first: on
Windows, connecting as a utility started SteamVR. Not running: exit 3 and the installer writes SteamVR's config
files, as on the headset.
- frame/payload: Frame Home, the panel, fenv-tool and the compositor layer built on the Steam Frame from this
source (installed there; locomotion tests 0 failed).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
- src/home_platform.h: what Frame Home and the panel need from the system (paths, finding and stopping each
other, running a tool, restarting, priorities) for SteamOS, Windows and Linux PCs. On a PC the environments are
Frame Studio's My Environments; Frame Home's own files in %LOCALAPPDATA%\Frame Home (Windows).
- src/openvr_loader.cpp: a PC build finds SteamVR's own OpenVR library at run time (openvrpaths.vrpath), so it runs
on any PC with SteamVR; Vulkan through volk. CMake: FRAME_HOME_PC (default on Windows and x86-64 Linux); the Steam
Frame build is unchanged.
- Windows: Frame Home is SteamVR's home app; SteamVR's classic environment shows a 360-degree picture of the current
home from its spawn (frame-home --panorama --spawn, made by the panel when the home changes) instead of Aurora
while Frame Home starts. Linux PCs: the Steam Frame's compositor layer, as on the headset.
- frame/pc: install-frame-home-pc.ps1 (+ .bat): online through SteamVR's API or offline in its config files; the
SteamVR settings it changes are saved and restored exactly on -Uninstall (tested in a sandbox both ways).
frame-switcher --uninstall. Studio: Properties > Headset > This PC installs it from pc/ beside Studio.
- Packaging and CI: pc/ in the Windows x64 and Linux x64 Studio downloads; FrameHome-PC-windows-x64.zip.
- Thumbnails come from where Frame Home starts you (the first spawn, eyes 1.6 m up): Studio's saves and the
panel's (frame-home --snapshot --spawn).
- docs/pc-steamvr.md.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
src/fenv_bundle.h: a ZIP of bundle.json and the .fenv files stored as-is, copied
in pieces (zip64 from the start when 4 GB or more). Write, read the manifest,
read one environment's fenv.json + thumbnail in place, unpack all or one
(.part then rename, checksummed; never replaces a different file: "name 2"),
validate.
fenv-tool bundle / unbundle, and info lists a bundle's environments. The
switcher unpacks bundles dropped into envs/ into their environments and
deletes them (frame-switcher --unpack-bundles does it at once). The installers
copy .fbundle files alongside .fenv; only a .fenv sets the one shown.
tools/bundletest checks it against real environments (--big: past 4 GB).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
- ImGuizmo is compiled with -fno-strict-aliasing on GCC/Clang: its type
punning let Clang for x64 turn gizmo drags into NaN transforms
- 32-bit: the .fenv packer keeps LZMA within a 32-bit address space (saves
failed with out-of-memory); failed saves are logged
- std::to_string of file times and the 32-bit descriptor handle cast compile
on every standard library
- Linux fonts: Noto Sans, then Liberation Sans, then DejaVu; the Play/Pause
button sizes to its label; macOS fonts are rasterized at Retina density
- self-test stages allow at least 3000 frames (software GPUs draw ~30 a second)
- headset payload rebuilt from this source
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Frame Studio now builds for Windows (x64, x86, ARM64), Linux (x64, x86, ARM64)
and macOS (Apple Silicon, Intel):
- studio/platform.h with Win32 and POSIX implementations (dialogs through
tinyfiledialogs on Linux/macOS), a GLFW window beside the Win32 one, and a
platform-neutral frame pacer
- MoltenVK support in the renderer (portability enumeration) and bundled in
the macOS app
- 32-bit builds: large-address-aware, LZMA packing within a 32-bit address space
- unaligned file reads in the loaders go through loadUnaligned (no UB)
- scripts/build-studio.sh, studio/build_windows.bat [x64|x86|arm64],
cmake/llvm-mingw.cmake, and a GitHub Actions workflow building every target
Frame Home installs without Studio: frame/install-frame-home.{sh,ps1} and
"Install Frame Home.bat" (packaged as FrameHome-installer.zip).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
