TrackedEntity over billboard not working when changing model visibility

[Aorrihtos]

What happened?

When having a entity with a 3D Model and a billboard, the default trackedEntity behaviour stops working if we disable the model visibility through show property.

Reproduction steps

1. Add a entity with 3D Model and Billboard
2. Set default 3D Model initial show value to false
3. Double click over billboard --> TrackedEntity behaviour OK
4. Set model show property to true
5. Double click again over the model --> Still trackedEntity behaviour OK
6. Set model show property to false
7. From now on, the trackedEntity over billboard does not work anymore

Sandcastle example

https://sandcastle.cesium.com/#c=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

Environment

Browser: Microsoft Edge, Google Chrome
CesiumJS Version: 1.135.0
Operating System: Windows

[jjspace]

Hi @Aorrihtos, thanks for the issue. I can confirm there is some weirdness related to tracking after hiding the model. Importantly when I was testing this the tracking switched to the billboard when hiding the model but after I untracked it and tried to track again it no longer worked.

I suspect this has something to do with the fact that you're adding the model and billboard into the same "entity" instead of separately. I think this might break the references somewhere when the internal code switches the tracking to the billboard but loses track of the entity or something.

I haven't had time to dig into this further but I wonder if you are able to reproduce the problem in previous versions of CesiumJS. I don't think we've touched the entity tracking code since back in March in this pr. That would've been released in 1.128