Select the MainLevel Node
Add a New Node3D as a child
Instantiate a Lava Scene as a child
To resize the pools and create collision shapes
We need access to the children of the Lava scene
Right-Click the Lava node
Now we have access to the children
Select the MeshInstance3D of the Lava
Resize the plane to fit the courtyard room
Then find the Mesh button in the viewport
Press it and choose Create CollisionShape
Now select the OmniLight3D node
Increase the Range to 20.0