Other options of positioning objects in real world without Spatial Mapping; Holo Lens 1 / MRTK

[sijan2405]

Hallo I'm currently working for a client on a Holo Lens 1 /Mixed Reality-Application.

My client wants to place the virtual objects firmly on pillars, similar to a museum. Normally I would use spatial mapping and local world anchors to do that.

But the problem is that the holo lens don't recognise the room, because the room and pillars are all very dark or black. And the anchors are connected with the mapping of the room. So that doesn't work.

I know that there is an option of using QR-code to position object relative to the position of this QR-code, but Holo Lens 1 can't capture QR-code (just Holo Lens 2). Another option would be vuforia but I don't want to use it, because its to expensive for the project.

So now my question: What other options do I have to place objects without spatial mapping / world anchors, so that they are always on the right position in the room?

[#2]

HoloLens 1 can capture ArUco markers via the color camera! It's a lot of work to set this up since this goes through OpenCV, but SpectatorView may have some sample code that might help a bit if you choose to go this route.
https://github.com/microsoft/MixedReality-SpectatorView/tree/master/src/SpectatorView.Unity/Assets/S...

If you're losing tracking or not recognizing the room, I would seriously consider adding visual features to the room as well! Have some posters on the wall, a rug with some texture to it, sign-posts, or other objects themed with the experience, etc. This will likely result in a much better experience, more stable experience for users, as well as open back up the option to use world anchors.