I have 3 objects: human model, pants and 1 armature for both. Before I started work on pants, I made few animations for body (run, idle). Initial problem was that the pants partially fall into the character during the run animation. I decided to fix that with shape keys. So I made 18 shape keys which made the pants looks correctly in run animation. But when I change animation in armature, shape keys still affect and when I try to export (.fbx for Unity), shape keys change output animations.
So, how can I use key shapes only for 1 animation?
P.S. I know about cloth modifier and weight painting. Both approaches don't work well in my case.