Trying to run big scenes on mobile devices.

Hello friends I am trying to create big scenes like whole city for mobile devices it works good for PC and I had taken almost all precautions for making it compatible and efficient. But some time in PC its lags fps is low and in mobile devices it gives big issue. So can you please tell me how expert people avoid these issue and create great games for mobile devices as well in unity. If there is any link suggesting some tips and tricks to make games more efficient and should not give performance issues, please help me.

Join as many game objects as possible.(reduces drawcalls).

Instead of per object material use texture atlases, this way you have less materials which also means less drawcalls.

Using advanced shaders like bumped ,specular can really be an issue, make sure you use them only where you REALLY need them.

Watch your polycount ! Delete faces that cant be seen! Ex : a rock fit into ground, the part that is in the ground is not seen , so it doesent need faces.( modeling)

Its for the best to never go pass 1024 resolution for your textures!

Level of detail is your friend ! Object far away dont need all the details since the player cant really see.

You can use fog and decrease the camera view distance! You can save quite a lot of processing power this way.

Make sure you join as much as possible! But do it in “chunks” not whole areas! Merging too many objects will make frustum culling ineficient!

Hope these tips will help you a bit :).

Employ this:

http://docs.unity3d.com/Documentation/ScriptReference/Renderer-isVisible.html

in conjunction with this:

http://docs.unity3d.com/Documentation/ScriptReference/Renderer-enabled.html