`bot.pathfinder.goto` sometimes never finish if goal is GoalNear and the block is not full height

[nishio]

Sometimes bot.pathfinder.goto never finish. It may related floating-point calculation.

Here is my code:

const { x, y, z } = toHarvest.position;
const goal = new GoalNear(x, y, z, 2);
if (!goal.isEnd(bot.entity.position)) {
  console.log("go to ", [x, y, z], "from ", bot.entity.position);
  await bot.pathfinder.goto(goal);
  console.log("done");
}

And it stop after the following message:

go to  [ -33, 63, -214 ] from  Vec3 { x: -28.55625503370811, y: 62.875, z: -213.3506397248765 }

GoalNear.isEnd is false and bot won't walk.

Is there any workaround?

[Karang]

If there is an error, goto reject the promise (which throws and exception that should be catched).
Try to catch and print the error:

try {
  await bot.pathfinder.goto(goal)
} catch (e) {
  console.log(e)
}

What makes you think it is related to floating point calculation ?

[nishio]

I already enclosed it with try/catch and there are no error.

I'm not confident that it is related to floating point calculation. Any other suggestion?

[nishio]

The code is usually success, but in a small probability bot stops without any error thrown. It is reproductive. Here are some cases:

go to  [ -28, 63, -212 ] from  Vec3 { x: -30.5, y: 62.875, z: -211.68502145455264 }
go to  [ -33, 63, -213 ] from  Vec3 { x: -28.5, y: 62.875, z: -212.3358946346443 }
go to  [ -35, 63, -211 ] from  Vec3 { x: -33.4805719963985, y: 62.875, z: -213.31170003933832 }

The bot stands on a flat farm of soul sand and nether wart.

[nishio]

My first guess about radius boundary looks not correct. I changed the title.
Here are some other cases with distances:

go to  [ -35, 63, -210 ] from  Vec3 { x: -34.327009310748934, y: 62.875, z: -212.6377405258382 } distance: 2.7251085390251646
go to  [ -29, 63, -208 ] from  Vec3 { x: -31.623865659091162, y: 62.875, z: -206.42575916155076 } distance: 3.0624386058171473
go to  [ -28, 63, -213 ] from  Vec3 { x: -27.5, y: 62.875, z: -209.5 } distance: 3.5377429245212264

Is there any way to observe internal path-finding status? I wonder why the bot won't walk.

[nishio]

I added console.log in bot.pathfinder.getPathTo and found const result = astarContext.compute(); return successful result, sometimes bot won't walk and never achieve the goal.

I feel it is not related to GoalNear.

[nishio]

At https://github.com/PrismarineJS/mineflayer-pathfinder/blob/master/index.js#L384
nextPoint was

Move {
  x: -32.5,
  y: 62.875,
  z: -208.5,
  remainingBlocks: 0,
  cost: 1,
  toBreak: [],
  toPlace: [],
  parkour: false,
  hash: '-33,63,-209'
}

bot.entity.position was { x: -32.68931395891055, y: 62.875, z: -208.51950746279664 }

They are close. At https://github.com/PrismarineJS/mineflayer-pathfinder/blob/master/index.js#L449
dx, dy, dz are 0.18931395891055303 0 0.019507462796639174.

However, after that it repeats path.length === 0
https://github.com/PrismarineJS/mineflayer-pathfinder/blob/master/index.js#L361

It checks stateGoal.isEnd(bot.entity.position.floored()) repeatedly, and it is false.
bot.entity.position.floored() is { x: -33, y: 62, z: -209 }.

It looks the case that bot.entity.position is in the boundary of the goal, but bot.entity.position.floored() is not in it.

[nishio]

By changing bot.entity.position.floored() to bot.entity.position, it works well in my case. Again, I use GoalNear and it has spherical boundary. I see there are many type of goals. I'm not sure some of those goals require floored position.

[Karang]

There seems to be an issue with the height (y) of the block. What block is it standing on at the end ?

[nishio]

What block is it standing on at the end ?

Soul sand, its height is 0.875.

By changing bot.entity.position.floored() to bot.entity.position, it works well in my case.

Sorry, it decrease the frequency but not fix the problem. I recover to the original.

At this code:
https://github.com/PrismarineJS/mineflayer-pathfinder/blob/master/index.js#L361
After path.length === 0, if isEnd is false, it does not emit goal_reached nor path_update. There are nothing changes the situation, so await bot.pathfinder.goto(goal) never finish.

Changing bot.entity.position.floored() to bot.entity.position makes the X-Z boundary broaden and decrease the frequency of the problem.

[nishio]

Here is an illustration:
https://gyazo.com/213c3d81da2ab7fca00bd1517367ee26

[nishio]

Based on the knowledge above, I changed GoalNear to GoalNearXZ. It looks work well in my case. I'll fix the title of the issue.

[IceTank]

This pr #268 should have fixed this issue. Feel free to reopen when you think there are still issues with this.