Assetbundle size issue when I make scenes(.unity3d files)

Question

I'm trying to reduce assetbundle size.

Most of other assetbundles size are decreased by just modify max texture size in texture importer setting

But scene assetbundle does not.

when i build assetbundle with scenes, 'Levels' take a big size.

what means 'Levels'? and how can i reduce this size?

below is part of unity editor log when building bundle.

***Player size statistics***
Level 0 'Assets/DungeonScenes/Plain/Dungeon_Plain_01.unity' uses 3.2 MB compressed / 12.0 MB     uncompressed.
Total compressed size 3.2 MB. Total uncompressed size 12.0 MB.

Textures      6.6 mb     55.1% 
Meshes        112.1 kb   0.9% 
Animations    14.4 kb    0.1% 
Sounds        11.0 kb    0.1% 
Shaders       766.4 kb   6.3% 
Other Assets  27.3 kb    0.2% 
Levels        4.4 mb     37.0% 
Scripts       1.1 kb     0.0% 
Included DLLs 0.0 kb     0.0% 
File headers  28.8 kb    0.2% 
Complete size 12.0 mb    100.0% 

To test, Just one scene is included, but real case, there is 10 scenes(.unity3d) in one bundle, and 'Levels' size are almost 80mb

thanks in advance, and sorry for my poor english

Answer 1

You can reduce 'Levels' size by making less objects in hireachy 'static'. Like "Occluder static" or "Navigation static" etc ~