Graphics Problem when running Qt-5/OpenCASCADE linux application in Windows-10/WSL with VcXsrv X-server

Hello everyone,

I recently came across a graphics problem, when I tried to run my linux application with Qt (5.15) and OpenCASCASE (7.4) on a Windows-10 system inside the Windows Subsystem for Linux (WSL) system.

I create the viewer widget very much like in the OCC C++ sample. This works very nicely in Linux. In Windows/WSL on the other hand, I see a lot of artifacts. Not in the OCC viewer. The image there is without errors. But everywhere across the other Qt-controls and widgets nasty rectangular black artifacts appear.

In the WSL X-server I have disabled native OpenGL and software rendering is used:

$ glxinfo -B
name of display: localhost:0
display: localhost:0  screen: 0
direct rendering: Yes
Extended renderer info (GLX_MESA_query_renderer):
    Vendor: VMware, Inc. (0xffffffff)
    Device: llvmpipe (LLVM 10.0.0, 256 bits) (0xffffffff)
    Version: 20.0.8
    Accelerated: no
    Video memory: 2047MB
    Unified memory: no
    Preferred profile: core (0x1)
    Max core profile version: 3.3
    Max compat profile version: 3.1
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.1
OpenGL vendor string: VMware, Inc.
OpenGL renderer string: llvmpipe (LLVM 10.0.0, 256 bits)
OpenGL core profile version string: 3.3 (Core Profile) Mesa 20.0.8
OpenGL core profile shading language version string: 3.30
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile

OpenGL version string: 3.1 Mesa 20.0.8
OpenGL shading language version string: 1.40
OpenGL context flags: (none)

OpenGL ES profile version string: OpenGL ES 3.1 Mesa 20.0.8
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.10

on the linux machine:

$ glxinfo -B
name of display: :0
display: :0  screen: 0
direct rendering: Yes
Memory info (GL_NVX_gpu_memory_info):
    Dedicated video memory: 2048 MB
    Total available memory: 2048 MB
    Currently available dedicated video memory: 1108 MB
OpenGL vendor string: NVIDIA Corporation
OpenGL renderer string: Quadro M600M/PCIe/SSE2
OpenGL core profile version string: 4.6.0 NVIDIA 460.73.01
OpenGL core profile shading language version string: 4.60 NVIDIA
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile

OpenGL version string: 4.6.0 NVIDIA 460.73.01
OpenGL shading language version string: 4.60 NVIDIA
OpenGL context flags: (none)
OpenGL profile mask: (none)

OpenGL ES profile version string: OpenGL ES 3.2 NVIDIA 460.73.01
OpenGL ES profile shading language version string: OpenGL ES GLSL ES 3.20

I'm a bit lost about how to proceed in this case. Do you have any hints what to attempt to remove these artifacts?

Note: I have also used programs with VTK-9 (paraview) in this environment and works without artifacts.

Thanks for any hints and

Regards, Hannes