AR expert needed for detecting the ceiling

Job ID: 31641766

Budget: $250 – $750 USD

I have a unity 3d project.
This is the ceiling fan AR project.
Now I have a problem for detecting ceiling.
When I put ceiling fan on the ceiling of the room, the fan does not fixed.
When I move the iphone, it moves on the ceiling now.
I hope to meet someone who can fix this problem.