My own scene in isaac sim

Hello, I have some questions about using my own scene in isaac sim.

I made a own scene (.obj) for using in isaac sim.

→ this fig is the picture that i clicked all meshes.

And i followed the tutorial ( 5. ROS2 Navigation ).
At first, i made a occupancy map for my scene, but there’s nothing occupied. My occupancy map is like below.

So i put some assets provided in Isaac (like box, robot etc… ). But also nothing in my occupancy map like below.
1. There are meshes of trees and building, boxes(provided to isaac asset) here, but are they originally unoccupied?

And When i put some boxes on here, that also be occupied ( the occupancy map result is same with above)
2. why those are unoccupied? Or Did i do something wrong?
( The other sceneS (hospital, office etc)'s occupancy map had some occupied things (wheel chair, boxes etc. Maybe i missed some process… TT )

Anyway, i loaded that scene in isaac and i put 3 robots(carters used in multi_robot hospital scene) on that scene. And i played, then the scene sank to the floor and the robots flew around.
I did add the “Rigid body with colliders preset” on “node_38c2be~~” ( below picture ). And All meshes are in here(node_38c2be…).

3. How could i use my own scene not sank to the floor? And How should i do robots to fall to the bottom of the scene?

Thank you for reading this topic and Anyone who know this problem… help me!

Did you tried append only “collider preset” without “rigid body”?

@siam33 , were you able to resolve the issues?

No, Not yet…

What Z height range did you use for the occupancy map generation?
Does that Z height range intersect the trees etc?