The offsets are applied after toggling positional tracking off, so that
the view does not jump at that moment. But when changing the base pose,
keeping that offset doesn't make sense. Especially with landmarks, which
are supposed to give precise positions/rotations to jump to. For that
part the VR Scene Inspection Add-on will need a little adjustment
though.
Also exposes an explicit function to the Python API to reset the
offsets, to be used by the Add-on.
This is mostly untested since I don't have access to an HMD currently.
The text and icon were supposed to change but didn't reliably, which was
a race condition I think. It depended on how fast the OpenXR runtime
would transition the session state.
This also makes sure the correct notifier is sent on session exit.
NOTE: While most of the milestone 1 goals are there, a few smaller features and
improvements are still to be done.
Big picture of this milestone: Initial, OpenXR-based virtual reality support
for users and foundation for advanced use cases.
Maniphest Task: https://developer.blender.org/T71347
The tasks contains more information about this milestone.
To be clear: This is not a feature rich VR implementation, it's focused on the
initial scene inspection use case. We intentionally focused on that, further
features like controller support are part of the next milestone.
- How to use?
Instructions on how to use this are here:
https://wiki.blender.org/wiki/User:Severin/GSoC-2019/How_to_Test
These will be updated and moved to a more official place (likely the manual) soon.
Currently Windows Mixed Reality and Oculus devices are usable. Valve/HTC
headsets don't support the OpenXR standard yet and hence, do not work with this
implementation.
---------------
This is the C-side implementation of the features added for initial VR
support as per milestone 1. A "VR Scene Inspection" Add-on will be
committed separately, to expose the VR functionality in the UI. It also
adds some further features for milestone 1, namely a landmarking system
(stored view locations in the VR space)
Main additions/features:
* Support for rendering viewports to an HMD, with good performance.
* Option to sync the VR view perspective with a fully interactive,
regular 3D View (VR-Mirror).
* Option to disable positional tracking. Keeps the current position (calculated
based on the VR eye center pose) when enabled while a VR session is running.
* Some regular viewport settings for the VR view
* RNA/Python-API to query and set VR session state information.
* WM-XR: Layer tying Ghost-XR to the Blender specific APIs/data
* wmSurface API: drawable, non-window container (manages Ghost-OpenGL and GPU
context)
* DNA/RNA for management of VR session settings
* `--debug-xr` and `--debug-xr-time` commandline options
* Utility batch & config file for using the Oculus runtime on Windows.
* Most VR data is runtime only. The exception is user settings which are saved
to files (`XrSessionSettings`).
* VR support can be disabled through the `WITH_XR_OPENXR` compiler flag.
For architecture and code documentation, see
https://wiki.blender.org/wiki/Source/Interface/XR.
---------------
A few thank you's:
* A huge shoutout to Ray Molenkamp for his help during the project - it would
have not been that successful without him!
* Sebastian Koenig and Simeon Conzendorf for testing and feedback!
* The reviewers, especially Brecht Van Lommel!
* Dalai Felinto for pushing and managing me to get this done ;)
* The OpenXR working group for providing an open standard. I think we're the
first bigger application to adopt OpenXR. Congratulations to them and
ourselves :)
This project started as a Google Summer of Code 2019 project - "Core Support of
Virtual Reality Headsets through OpenXR" (see
https://wiki.blender.org/wiki/User:Severin/GSoC-2019/).
Some further information, including ideas for further improvements can be found
in the final GSoC report:
https://wiki.blender.org/wiki/User:Severin/GSoC-2019/Final_Report
Differential Revisions: D6193, D7098
Reviewed by: Brecht Van Lommel, Jeroen Bakker
