Packaging is cooking all resources in content directory even if not referenced in project

Hi epic:

recently, i have find one problem about package project. I found the tool cooked all resources of content directory, even if it was not referenced in my project, just be included to the content directory. I know UE3 checks the reference of each content of my project before cooking . So i do not clearly about this in UE4. Can anyone give me some kindly ideas about cooking?

Thanks.

zql

I have got the reason. So close it please.