aliases, and turning off predictive tracking.

log.txt

$ bin/osvr_print_tree.exe
[OSVR] Connecting to default (local) host
[OSVR] Client context initialized for com.osvr.tools.printtree
[OSVR] Got connection to main OSVR server
[OSVR] Got updated path tree, processing
[OSVR] Connected 0 of 0 unconnected paths successfully
[OSVR] Connection process took 9ms: have connection to server, have path tree
[OSVR] Client context shut down for com.osvr.tools.printtree


[   StringElement] /display
                     - Contained value: {"hmd":{"device":{"Note":"Settings are also good for HDK 1.0","Version":"1.1","model":"HDK","num_displays":1,"vendor":"OSVR"},"distortion":{"k1_blue":0,"k1_green":0,"k1_red":0},"eyes":[{"center_proj_x":0.5,"center_proj_y":0.5,"rotate_180":0},{"center_proj_x":0.5,"center_proj_y":0.5,"rotate_180":0}],"field_of_view":{"monocular_horizontal":90,"monocular_vertical":101.25,"overlap_percent":100,"pitch_tilt":0},"rendering":{"left_roll":0,"right_roll":0},"resolutions":[{"display_mode":"horz_side_by_side","height":1080,"swap_eyes":0,"video_inputs":1,"width":1920}]},"meta":{"schemaVersion":1}}

[   DeviceElement] /com_osvr_Multiserver/OSVRHackerDevKit0
                     - corresponds to com_osvr_Multiserver/OSVRHackerDevKit0@localhost
[InterfaceElement] /com_osvr_Multiserver/OSVRHackerDevKit0/tracker
[   SensorElement] /com_osvr_Multiserver/OSVRHackerDevKit0/tracker/0
[    AliasElement] /com_osvr_Multiserver/OSVRHackerDevKit0/semantic/hmd
                     -> /com_osvr_Multiserver/OSVRHackerDevKit0/tracker/0
[   DeviceElement] /com_osvr_Multiserver/OSVRHackerDevKitPrediction0
                     - corresponds to com_osvr_Multiserver/OSVRHackerDevKitPrediction0@localhost
[InterfaceElement] /com_osvr_Multiserver/OSVRHackerDevKitPrediction0/tracker
[   SensorElement] /com_osvr_Multiserver/OSVRHackerDevKitPrediction0/tracker/0
[    AliasElement] /com_osvr_Multiserver/OSVRHackerDevKitPrediction0/semantic/hmd
                     -> /com_osvr_Multiserver/OSVRHackerDevKitPrediction0/tracker/0
[    AliasElement] /me/head
                     -> {"child":{"changeBasis":{"x":"-x","y":"-z","z":"y"},"child":"/com_osvr_Multiserver/OSVRHackerDevKitPrediction0/semantic/hmd"},"rotate":{"axis":"x","degrees":90}}

syntax.md

so it looks like here, the /me/head is where the transform occurs (it can also occur back at the per-device semantic paths), if you have a section like

"aliases": {
  "/me/head": {"child":{"changeBasis":{"x":"-x","y":"-z","z":"y"},"child":"/com_osvr_Multiserver/OSVRHackerDevKit0/semantic/hmd"},"rotate":{"axis":"x","degrees":90}}
}

that should change the results of osvr_print_tree to effectively turn off predictive tracking.