ARKit Meshing (ARMeshManager) density

[KyryloKuzyk]

Is your feature request related to a problem? Please describe.
ARMeshManager.density is not working with ARKit. The documentation says 'Not all platforms are supported' but it doesn't say which ones are.

Describe the solution you'd like
Add the support for ARMeshManager.density with ARKit.

Describe alternatives you've considered
Explicitly describe what platforms support setting density.

[tdmowrer]

I'll add better documentation to indicate what is supported by the ARKit package, but we cannot add support for the mesh density feature on iOS unless it is implemented by Apple.

[tdmowrer]

For what it's worth, it is actually documented, albeit not quite as clearly as saying "density is not supported": https://docs.unity3d.com/Packages/com.unity.xr.arkit@4.0/manual/arkit-meshing.html#other-armeshmanager-settings:

For the ARKit implementation, only these 3 settings affect the performance and output of ARKit meshing.

We'll update it to be more explicit, though.

[NumaNumaNuma]

we cannot add support for the mesh density feature on iOS unless it is implemented by Apple.

There are several iOS scanning apps which offer different density/resolution settings, is there a hard limitation preventing Unity from doing the same thing? I'm guessing they're reading the depth information and sampling that at different resolutions to generate their mesh.

[tdmowrer]

We do not generate the mesh; ARKit does. For some time, there have been ARKit-based apps that use custom solutions to generate the mesh based on ARKit's point cloud. There may be some that do something similar with the LiDAR sensor.

By contrast, ARFoundation's ARMeshManager relies entirely on ARKit to generate the mesh.

[NumaNumaNuma]

That makes sense thanks!

[tdmowrer]

Documentation updated.