Mobs automatically relocate to a higher priority seat if one is vacated.

Partner Rank: 3

Partner Team Reporting: Noxcrew

Verification builds: 1.9.15- 1658980

Summary:

NOTE: I was asked to submit this as a bug by Adrian Orszulak. I can see how this could be seen as a feature request, but whatever this is considered it should be looked at.

 

When you have a mount with multiple seats, mobs will currently move to inhabit the highest priority seat. If they are in a lower priority seat and a higher seat opens up, they will move from their seat and inherit the higher priority one. This is an issue when using mobs riding mobs to act as a hybrid mob for a boss. An example of this would be a large robot which could have it's arms and head shot off. With the current behavior, if I designed a way to sit a "head" mob and two "arm" mobs on the body, and the head was in the highest priority seat, having that killed before both arms would result in an arm relocating to be in the head seat, which would provide a bad visual.

 

Ideally, we would have control over whether or not this happens at all, and the ability to have it happen only over a specific selection of seats. We should be able to define families that can sit in each individual seat, instead of having to define it once for the entire group of seats.

 

Impact:

This issue keeps us from making cool content.

Repro Steps:

1. Either create a new BP and add the attached horse.json, or replace the horse.json in an existing pack.
2. Open the world
3. /summon horse. Notice how there are three sheep and a witch "riding" the horse. The witch is in the highest priority seat.
4. /kill @e[type=witch]
5. Notice how there is now a sheep in the spot the witch vacated.

 

Observed Results:

 The riders move to higher priority seats.

Expected Results:

 The riders do not move, or ideally we have the ability to control the behavior.

Screenshots/Videos attached: 

 https://www.dropbox.com/s/kjjqkjkp4jq5jz2/Multiple%20Mounts.flv?dl=0

 

Regression Builds:

 This behavior has always existed as far as I know, at least since boats got two seats.