[qt/qt/qtquick3d]: Summary of bulk changes made

Git repository change summary for qt/qt/qtquick3d
Pushed by mirror-service into branch 'dev'.
Changed from e47f797d4d6fc598db5863f2d861b862112bda83 to d8f207d32a2c87b15be15548129eb25c5b205002
Acknowledgement was received that this change introduces only existing code that has been pushed to another public open source repository.

This change contains the following new commits:

Git commit d3ceaa2b74723e4d42fd54588e0adc27fb71c957 by Christian Strømme on 05/08/2026 at 07:08..
Don't remove a non-child node from a layer

A layer does not set a parent reference on its direct children.
Those children (the View3D's scene root, the ImportScene dummy,
explicit cameras) are owned and kept alive by other subsystems,
e.g. the scene root by the scene manager, so leaving their parent
unset keeps the layer's lifetime decoupled from theirs, as  they
can outlive the layer.
Sharing of imported scenes is handled by the ImportScene dummy
injected in QSSGRenderLayer::setImportScene().

Added a test that removing a foreign node from a layer leaves the
list it belongs to intact.

Fixes: QTBUG-147451
Pick-to: 6.12 6.11
Change-Id: I612b97554cf625ed85e5138daa718fdb810f7263
Reviewed-by: Andy Nichols <[email protected]>
https://invent.kde.org/qt/qt/qtquick3d/-/commit/d3ceaa2b74723e4d42fd54588e0adc27fb71c957

Git commit d8f207d32a2c87b15be15548129eb25c5b205002 by Tomi Korpipää (on behalf of Christian Strømme) on 05/08/2026 at 09:20..
Fix layers support for particles

The particle system creates hidden internal nodes that do not take
part in the normal processing, meaning the particle system needs to
maintain and update the layers for the nodes it creates itself. This
was unfortunately missed in the initial implementation.
Note that this only applies to the internally created nodes, like the
sprite and line particles. For content  the instantiated from a
user-provided delegate (ModelParticle3D and ModelBlendParticle3D) the
layers property is left alone, since the layers property is not inherited
and stamping user content would override explicit layer assignments
made in the delegate. While this design causes a slightly different
behavior for the two types of particles, it follows intended behavior
of the layers API and also avoids that we try to be cleaver and guess
what the user actually wants to do.

Added particle effects to the layers example, including a model
particle with a compound delegate where each model assigns its own
content layer, and a visual test.

Pick-to: 6.12 6.11 6.11.2
Change-Id: I0b2b08dfe6e19b7cbf4fcde81e485f1c360ef99b
Reviewed-by: Tomi Korpipää <[email protected]>
https://invent.kde.org/qt/qt/qtquick3d/-/commit/d8f207d32a2c87b15be15548129eb25c5b205002