The bug
If you have skeleton or another mob riding a horse for example, it will jump onto a block and start spinning repeatedly. I think this is because when the skeleton tried to go down a block it is using its own AI and position (thinking it is floating) instead of the horse's AI (which already is on the ground) so it starts spinning because they can't walk.
Implications
Mobs riding for example a horse get stuck at block edges
Horse has saddle: Horse and rider start spinning
Horse has no saddle (for example skeleton trap): Horse and riding start wiggling
(?) Mobs causing ridden mob to walk up blocks instead of going down because they think they are floating
How to reproduce
Summon a mob riding a horse
/summon horse ~ ~ ~ {Tame:1b,Passengers:[{id:husk}]}Summon a villager or switch to Survival mode and walk up some blocks
Linked issues
discovered while testing 1
is blocked by 1
is duplicated by 1
Attachments
Comments 7
By joy it does. My apologies. Couldn't find it been looking. Yours is specific i guess that's why I couldn't find it. It applies to all mobs that can fit through one block while trying to do so riding a horse or such.
This can easily be seen with mobs inside a boat with no gravity.
/summon Boat ~ ~20 ~ {NoGravity:1,Passengers:[{id:Zombie}]}
The zombie just twitches back and forth inside the boat when trying to path towards players. :|
Cannot reproduce this in 20w07a. Also make sure to test with a horse without saddle due to MC-172387.
Is someone still experiencing this?
I added a gif of a skeleton riding a mount (mule). The AI has definitely improved!!
Though they seem to have real difficulty climbing up and down tough and steep terrain. Probably because of how big the mount is. Smooth terrain is working. Though when riding over flat land, the mule goes sideways, worth mentioning I hope.
Can someone please check, if this still applies to 1.15.2 or the latest 1.16 development snapshot (currently that is 20w07a)?
I believe this issue either relates to or duplicates MC-111159