[Other issue]: Layer are not in buildng_map-tools level

[cwrx777]

Before proceeding, is there an existing issue or discussion for this?

• I have done a search for similar issues and discussions.

Description

To implement and add layer in level.

[luca-della-vedova]

Hello!

Just thought I'd bring up that I did a bit of experimenting with this and the main challenge I found is in publishing the images.
Specifically, when populating images in the Level message that the building_map_server publishes to downstream packages.

It is true that the message is designed as an array, however since until now only a single image has been present for each floor (its reference drawing) the code paths to exploit the array property are not really tested.
Specifically I encountered exceptions in rmf_visualization in the image blending path (since it never got triggered before) and it is unclear to me how rmf-web would behave if multiple images are sent.
Still, I agree this would be a very useful feature! Just thought I'd share my findings if you plan to work on it!