What I expected to happen was...:
render distant only effect view
What actually happened was...:
when I set render distant to 2, the pigmen at 8 chunk away didn't trigger until I set render distant to 16 or walk closer
Steps to Reproduce:
1. Set render distant to 2
2. Trigger a pigman
3. Lure them somewhere or kill them
4. make sure you can't see anymore
5. Set render distant to 16
6. you should see pigmen started to see you after you set the render distant
Linked issues
Comments

Mobs are not processed when they are not loaded.
Duplicate of MC-48868