I have a couple of entities that I’m adding to a player as passengers. However, whenever the player turns, they don’t turn with. Why is this? How can I fix it?
This is because this is not something that passengers do in vanilla. Instead it is vehicle-specific. If you want to fix it, add a listener to MoveEntityEvent, check if the entity is a player and has passengers and if rotation is changing, and if so change the passengers’ rotations by the same amount.
Also, this is off-topic and should be moved to #plugins:plugin-development.
I’m doing this but it is not making the stand follow the rotation of the player’s head.
stand.setRotation(player.getHeadRotation());
where stand is an instance of ArmorStand and player is a Player instance. stand is what calls the passenger of player.
Try setting the rotation to an arbitrary amount, with a log message to ensure the code is executing, just to make sure that you actually can set the rotation of a passenger entity.