Add WMR Lighthouse hacky wiki entry

content/docs/fossvr/wmr_lighthouse_hacky.md

@@ -0,0 +1,73 @@
+---
+title: WMR Lighthouse (no SteamVR)
+weight: 9000
+---
+# WMR Lighthouse (no SteamVR)
+
+This describes a WMR Lighthouse setup using the `steamvr_lh` driver.
+
+It's different from [WMR Lighthouse](/docs/steamvr/wmr-lighthouse)
+
+This doesn't use steamvr to re-map the head from some lighthouse tracking device.
+Instead it does this natively, so SteamVR is only necessary for the proprietary `steamvr_lh` driver.
+
+For now this is a hacky approach as Monado's builders don't support the functionality yet:
+
+* https://gitlab.freedesktop.org/monado/monado/-/issues/459
+* https://gitlab.freedesktop.org/monado/monado/-/issues/288
+
+I made this for WMR as i have a reverb G2 & vive 1 (used only for it's 2 watchman dongles)
+
+you can easily adapt this for other headsets in a hacky way, until these issues are closed.
+
+I use this as my only vr setup on arch and it works fine.
+
+## Setup:
+Setup your lighthouse system on SteamVR Windows. The Linux SteamVR version does not work well. On windows: Update everything, pair everything & setup your room boundaries.
+
+Linux setup:
+* install steam
+* Download SteamVR on Steam (try non beta version first)
+* configurations from windows copied over
+
+## How to copy your windows steam configurations to Linux
+* mount your windows drive (e.g. at `/mnt`)
+* `cp "/mnt/Program Files (x86)/Steam/config" ~/.steam/steam/ -r`
+
+## Build 
+Grab my hacky Monado
+
+`git clone https://gitlab.freedesktop.org/Zuzka/monado`
+
+(if it's too old, try to merge upstream into it and fix it)
+
+Ensure you have all required dependencies installed beforehand (Envision or Monado docs might help)
+
+`cmake -G Ninja  -B build -DCMAKE_INSTALL_PREFIX=/usr -DXRT_BUILD_DRIVER_SURVIVE=0 -DXRT_BUILD_DRIVER_VIVE=0 -DXRT_BUILD_DRIVER_STEAMVR_LIGHTHOUSE=1`
+
+`sudo ninja -C build install`
+
+You may get this error:
+
+```
+CMake Error at cmake/OptionWithDeps.cmake:141 (message):
+  XRT_BUILD_DRIVER_STEAMVR_LIGHTHOUSE specified but not available: failed
+  check XRT_HAVE_STEAM
+Call Stack (most recent call first):
+  CMakeLists.txt:327 (option_with_deps)
+```
+
+In which case it's okay to just comment (put # at beginning of line) of line 372.
+
+## USAGE:
+* set following environment variables in your e.g. bash_profile:
+* export LH_DEVICE_SERIAL="{YourSerial}"
+* get the actual tracking device serial via `motoc monitor` or by another way.
+
+## USEFUL RESOURCES:
+* https://monado.freedesktop.org/getting-started.html#installation-from-source
+* https://monado.freedesktop.org/valve-index-setup.html
+* check the commits on my branch for more info https://gitlab.freedesktop.org/Zuzka/monado
+* vive tracker 3.0 3d printable mount
+  * model: https://www.printables.com/model/107654-hp-reverb-g2-vive-tracker-mount
+