[QGIS-Developer] [Qgis-psc] Current state of QGIS and Qt 6 (good news!)

[Nyall Dawson]

On Fri, 19 Aug 2022 at 18:10, Martin Dobias <wonder.sk at gmail.com> wrote:
>
> Hi Nyall
>
> On Fri, Aug 19, 2022 at 2:26 AM Nyall Dawson <nyall.dawson at gmail.com> wrote:
>>
>>
>> For reference: when I open a 3D view the debug messages just spam out
>> thousands of "Unhandled texture format:
>> Qt3DRender::QAbstractTexture::RGB8_UNorm" Qt warnings.
>
>
> That looks like Qt3D is trying to use the new RHI renderer. Can you try to switch to the original OpenGL renderer by setting env variable QT3D_RENDERER=opengl ? It seems like the RHI renderer only supports some texture types [1]. We should actually enforce opengl renderer in the code (it seems RHI is the default now in qt6 [2]). The RHI renderer also does not support geometry shaders for now (which we use for line drawing). Fortunately it looks like the opengl renderer is not going disappear, at least from what I understand (although at some point in
> future it may be useful to migrate to RHI).

Thanks Martin! I can confirm that this fixes the issue. PR at
https://github.com/qgis/QGIS/pull/49887

Nyall

>
> Cheers
> Martin
>
> [1] https://github.com/qt/qt3d/blob/2f1bc82b35209aacd8d214a3c7e8e725bee85de6/src/plugins/renderers/rhi/textures/texture.cpp#L42
> [2] https://doc-snapshots.qt.io/qt6-dev/qt3drender-porting-to-rhi.html
>