Hey guys
I was just messing around with normal maps and lighting in Unity and I’m wondering why the point light is only lighting one half of the “sphere” its supposed to light. As you can see here, there are 3 point lights set up and its only lighting half of it. Why is this? and how do I fix it?
Thank You
FIXED 
Okay so I was scrolling down th Inspector of the material itself and I noticed right below my normal map there was note that said “This texture is not marked as a normal map” and a button “FIX NOW”,
clicked on it and it was the point light was acting perfectly…
Im sorry it might have just been me being stupid . Im new to Unity I didnt know you had to do this. Thank you all your effort!
Don't be sorry, this is a perfectly acceptable answer to a problem that showed itself as pretty odd behavior. :) Glad you got it fixed!
– CHPedersenYeah that makes sense! Good that you worked it out, and thanks for posting the answer for us!
– syclamothHey, I can't upvote 'cos I'm too new, but I just wanted to add that I had this exact problem (only the mesh was terrain), and this fixed it. Thanks!
– b3agzIf it is an FBX file, make sure on the fbx importer that for tangents and normals, you select CALCULATE, not Import.
what fbx importer are you talking about? I thought I would just need to go Assets>Import New Assets and then chose the fbx? if its the maya fbx exporter, I don't see any option for calculate. Can you please elaborate. Thank You =)
– anon90223192The fbx importer is the window that appears in the inspector when you select an asset in the project view. Unity uses it to determine exactly how it treats every new asset.
– syclamothIt is likely not a setting in the FBX importer, if native Unity planes behave the same. I must say, I find this really odd, too. Don't have a solution, unfortunately. O_O If you manage to nail this one, please post the cause and solution. :)
– CHPedersenI was having this issue recently with the ceiling of my scene. Checking the “Create from Grayscale” in normal map texture settings fixed the issue.
Is this a custom mesh? Could it be that some of the normals are flipped?
– asafsitnerWell at first it was a plane that I imported from Maya. Then I tried using a plane made inside Unity and it still had the same problem. Also note that this happens with spot lights as well.. I cant tell if it happens with directional lights since it lights the whole scene.
– anon90223192