How do i add geometry to the octree in the games_fps example

when i convert the glb to an obj and import it and add geometry and export it again as glb , it works as long as i just add some flat planes but when i add a more complex building with doors windows stairs and floors the player falls through the floor .what are the rules to add geometry to the octree ? and does everything has to be imported as 1 one singlemodel at once or can i glue extra models during the script ?

worldcollisionmod.glb (189.0 KB)
wordcollisionmod is the original with 4 planes added as elements . this still works .
worldcollisionmod2.glb (396.3 KB)wordcollisionmod2 is the same but with a house added on top of it . and this results in endless falling

testbucht2.glb (202.4 KB)with this , it works .i scaled the exampleworld huuuuuuuuuuuuuuge .in width and length and put the house on top of it and removed all the doors and windows . i lowered the gravity to 9.8 ; then i had to look 5 minutes at a black browserloading the thing but then it worked .

@steven any luck resolving this? Trying to do the same thing and have the same confusion