OpenXR/OpenVR (virtual reality support), new Python workbench WiP

[mittkonto]

Oh my

I have a dell visor and would love to serve as a guinea pig for this!

[saso]

https://github.com/cnlohr/cnovr
https://www.youtube.com/watch?v=fCiY-6XVcvE
https://www.youtube.com/watch?v=a2DjjG9wVY0

[Kunda1]

Hows this effort proceeding?

[kwahoo]

I made the first step towards truly vendor-independent VR implementation in the FreeCAD. This commit implements initial OpenXR support: https://github.com/kwahoo2/FreeCAD/comm ... e70ab1faaf

To compile the code, OpenXR SDK is needed https://github.com/KhronosGroup/OpenXR-SDK The BUILD_OPENXR option has to be set to ON.
To run an OpenXR runtime and loader is needed. On Linux this is delivered by Monado. Monado has limited support for a bunch of HMD's including HTC Vive, Valve Index and Sony Playstation VR.
Path for the OpenXR loader have to be defined before running the FreeCAD, eg.:

Code: Select all

XR_RUNTIME_JSON=/usr/local/share/openxr/1/openxr_monado.json freecad

On Windows OpenXR is supported by Windows Mixed Reality and Oculus headsets. I have NOT tested them due lack of hardware.

The initial OpenXR support I've implemented does not cover motion controllers and positional tracking is not tested. View can be moved by keyboard, same way as in the JR's original Rift implementation. This is because of limited support of my hardware in Monado library.

I hope, I'll see full OpenXR support by mine HMD manufacturer (Valve) in the near future. This is the main thing stopping me now:(
In the future the OpenXR should replace all VR backends in the FreeCAD, including original Rift support by Juergen and my OpenVR implementation.

Note: the openxr.hpp header requires C++14. This may (or not?) be an issue during merge.

[vocx]

...
Note: the openxr.hpp header requires C++14. This may (or not?) be an issue during merge.

Werner, the main developer of FreeCAD, has mentioned that FreeCAD isn't exactly the best place to try newer C++ features. He wants FreeCAD to be C++11 compliant but I'm not sure how much other standards are allowed.

FreeCAD is rather conservative with respect to the compiler version it uses because it emphasizes that it can be built on all supported releases of the most important Linux distributions (Debian, Ubuntu, openSuse, Fedora, ...). So, at the moment no C++ language features that require a higher version than C++14 should be used in the code.

If your units library requires C++20 or higher then it's not an option for FreeCAD at the moment.

[Kunda1]

Nevertheless, VR is the future. Blender is now getting more VR integration
see https://twitter.com/blender_org/status/ ... 6237722626
So this is an enormous step in the right direction. I hope we can sort out the c++ standard issues as we roll in to the future.

[kwahoo]

Sad news for Mac users:

SteamVR has ended macOS support so our team can focus on Windows and Linux.
We recommend that macOS users continue to opt into the SteamVR [macos] branches for access to legacy builds.
Users can opt into a branch by right-clicking on SteamVR in Steam, and selecting Properties... -> Betas.

With lack of OpenXR support this means basically death of VR on Mac.

[kwahoo]

Small update:
Valve released OpenXR Developer Preview for SteamVR
Unfortunately there is an issue. An OpenGL app (like FreeCAD) needs XR_KHR_opengl_enable extension. But it isn't supported by some runtimes.

At this moment:

• SteamVR runtime on Windows supports XR_KHR_vulkan_enable, XR_KHR_D3D11_enable and XR_KHR_D3D12_enable is planned
• SteamVR runtime on Linux supports XR_KHR_vulkan_enable
• Windows Mixed Reality runtime on Windows supports XR_KHR_D3D11_enable and XR_KHR_D3D12_enable

I asked about OpenGL support in SteamVR-OpenXR.

Blender workaround this issue by OpenGL-Direct3D shim. At this point Blender VR can run on Windows/SteamVR but not Linux/SteamVR.

If we cannot get XR_KHR_opengl_enable support, we need similar shim, but probably OpenGL-Vulkan instead OpenGL-Direct3D makes more sense because of cross-platform support.

EDIT 19.06.2020
https://store.steampowered.com/newshub/ ... 1406562401

OpenXR:

Added support for OpenGL on Linux. (Windows support for OpenGL is on the way.)

[Kunda1]

Any progress?

[kwahoo]

Sorry for delayed response.

The OpenXR support is almost done. I'm going to provide Appimages and windows executables in next few days.

phpBB [video]

Update:
Windows build and Linux Appimage are here.