Packets and shit

[long jewel]

Is there a way i can reliably calculate entity movement speed with this packet?

When sending it, if I send the value of one block in one packet 4 it is very fast to move the 4 blocks

but splitting the packet distance by half, and spreading it out over every 2 * x ticks x times, the entity moves a lot slower in said direction

Is there some way i can somehow calculate speed with this? Reason being is i need to get when the entity reaches a specific location in the world, and i dont want to rely on a client sending me the information that an entity is at x location for obvious reasons

[gilded skiff]

why do you need to calculate the speed - that is a PlayOut packet no?

i think the server does it by sending the location every 50ms, which makes it smooth enough for a client

[long jewel]

Yes, but the issue is say i want to move the entity in one block, sending the on block distance (4096) they move near instantly

you can see them move, but its just so fast

[long jewel]

Its for when the reach x location, if they read x location then i need to cancel navigation, or iterate to the next location in the navigation

its a client sided entity

this is moving the entity half a block each packet

[gilded skiff]

ah ok i get this, but i think you should just have a server side entity wrapper thing, that you can instantiate with a list of locations, that it will use - maybe interpolated from the pathetic result. call a tick method every server tick that sends the move packet to the clients

[long jewel]

yep thats what im setting up right now

[gilded skiff]

oh awesome lol

[long jewel]

its just i need to actually have some way to calculate the speed, reliable if that makes sense

[gilded skiff]

why do you need the speed?

[long jewel]

moveTo(vector, withSpeed);

a method like that essentially

in normal MC you can effect a entities speed by a single float value

[gilded skiff]

well speed is a scalar quantity so just find the default walk speed in mc

[long jewel]

Its just 1

[gilded skiff]

oh lol

does that work?

[long jewel]

well

idk how to actually do the math for it, thats my question

[gilded skiff]

well, what specifically is the issue?

[long jewel]

i assume i need to break the distance of up into seperate packets, based upon a specific speed divider?

[long jewel]

one sec

this is rly hard to explain

[gilded skiff]

id just take the difference between the current and next location, then use the components as the dx, dy, dz and plug that into the formula.

oh wait nvm you just need the current and target components for the formula

[long jewel]

Yeah, and another reason i want speed too

is sequential order of operations

I only want to send new instructions once current once complete, so waiting until it reached x distance is rather crucial

sec im trying to get a video

[gilded skiff]

how does jumping work? does it just go up?

[long jewel]

yeh + 1 to the y axis or 4096

[long jewel]

this is what happens when you send the max value (8 blocks) to the packet

its just so stupidly fast

but if i split the packet into smaller chunks and send them every say, 4 ticks then they move slower

so i need some formula to calculate that part there specifically

basically:

If I want an entity to move, at the default MC walking speed 2 blocks forward

What divider do I divide Vector(9332, 0, 32768) by (2 blocks) to get a list of Vectors to send to the packet, as well as what interval would they need to get sent at?

I think thats the absolute best way ican explain it

wait

i could do blocks per tick?

wait that might work

okay i got something kind of down

but, unable to figure out some type of formula for the max x 🤔

[gilded skiff]

i’ll take a look in a bit - am out walking

[long jewel]

kk!

oh oh

think i got it

time to test

ouu

did it with 8 blocks at .1 blocks per tick

i guess thats about walking speed huh

[gilded skiff]

are you using packetEvents?

[long jewel]

raw NMS

well

remapped

[gilded skiff]

huh ok

didn’t realise there was a static .Pos constructor

[long jewel]

Yeah Col mentioned it yesterday

it matches that entity packet position

next part is calculating the fall speed when entity walks over air now

[gilded skiff]

that’s not the vector you need tho. you need the vector of the target - the vector of the origin

that will give you like (2, 0, 0)

[long jewel]

Yeah im just using those values for testing rn

[gilded skiff]

which is the movement vector

[long jewel]

i just wanted to get speed working before i added the actual max, that parts easy

because when i did the movement in one packet, it was near instant

cause your pathfinding is in block increments, it sent 1, 0, 1 like so and it did stuff like

this one sec

This is them moving one block specifically using my location - my location + 1 on x and z

which would be, one block

and they basically move the one single block instantaneously

[long jewel]

so i needed them to slow down base on a specific rate thats easily controlled by a number which this seems to do

lemme try something and ill brb

[gilded skiff]

which is why an interpolation method is on the todo list

but if you can find a way to do that, it would be handy

i was looking at splines, but that’s a lot of maths. it’s is conceptually just an algorithm for generating a polynomial close to the path for the points

[long jewel]

wym by that?

[gilded skiff]

then you could sample that, but eh it looked a lot of work

[grim iris]

One thing that made me overthink interpolation is like

[long jewel]

I personally like the per block pathfinding, its perfect for mc protocol

[grim iris]

what if we made a 3d algorithm for smooth camera movement

where we defined a couple points and it made a round movement set

[gilded skiff]

as in, you give it 3 points and it generates the 0.1 distance locations between them. that could be quite easy if you just want locations between two points actually

[long jewel]

omg

its working

nvm

he ran away

[gilded skiff]

yeh that’s the concept behind splines really, i just find them hard to grasp

the maths gets out of hand kinda fast, a lot of variables and i find it hard to know how to sample

would be cool tho - probably some existing code

[long jewel]

Yeah thats what im doing rn

[gilded skiff]

oh cool 😎

[long jewel]

Im just making a basic moveTo(x, y, z)

And its going to be just x y z from pathetic points

which are, almost always 1, just in a specific direction

i was actually thinking about just block per block moving

like move(Direction)

and it moves the direction one block

but for now moveTo

[gilded skiff]

could have a direction enum, but i think it would look nicer broken into smaller intervals

rather than like teleporting ahaha

[long jewel]

thats essentially what im trying to do, break the points into smaller

the actual speed is fine, but it doesnt respect the destination

im running that method every 60 ticks and x y z is my player location

and he kinda just:

my other video corrupted

but you can see there he just...

walks away lol

better video

[gilded skiff]

he walks through you no?

[long jewel]

thats fine for now

ignore all that stuff

only his movements, ill work on the gravity and him going through blocks later

hes not a real entity so you have to manually do all that

[gilded skiff]

looks good atm tho - i would probably structure the code differently to you but that’s just personal preference :) - i’ll check in #1001384149246038048 tomorrow for any updates ahahah

[long jewel]

yeah rn its just testing purposes, once its all working ill fully implement it cause the entire thing is async

Just cant figure out why the npc endless goes away, but ill figure it out hopefully x)

[long jewel]

man this shits hard as fuck

why cant anything in mc ever be simple lmao

okay okay

got everything now besides my distance calculations fucked somehow for his movements

i think its sending too many packets and makes em go over

[long jewel]

https://paste.md-5.net/amorexuxal.cpp

Alright so I've boiled the code down to this, however, the entity doesn't really go to the exact location, i feel like its cutting short or its warping the x/y/z somehow

Im terrible it math

[long jewel]

AYOOOOO

FINALLY

https://paste.md-5.net/unubobabok.cpp

Gonna clean it up a bunch after a quick nap, i kinda was just mashing in any equation and casting and rounding until shit worked

[14:35:44 WARN]: [Civilizations] Task #103492 for Civilizations v1.0-SNAPSHOT generated an exception
java.lang.ArithmeticException: / by zero

nOICE

bbl

[gilded skiff]

eyyy looks sick

[long jewel]

that one was actually broken

this one, not :))

im working on chunk calculations and redoing the packet sending format

ill need to fix rotation of but thats simple

i think the hard part is gonna keeping location synced for all players

[gilded skiff]

i think if you do xx+=2 that might look better

but yeah looks good

[grim iris]

you can send an absolute position packet whenever it starts and finishes its trajectory

sure it has some more network overhead but it's simpler than all the cpu stuff you'd do to keep it in sync

[gilded skiff]

i think that’s why it’s probably good to have a tick() method that is called every 50ms or so, which keeps all clients up-to-date. maybe have a sendPosition() method which uses the current location and then send relative packets in that

[gilded skiff]

and that ^

[grim iris]

Other than that, you can also look into lerping rotation like mobs do

say like, rotate a max of 5deg / tick

you can get the yaw by doing double angleInRad = playerDirection.angle(targetLocation)

[long jewel]

that would just me making it move faster

so you increase the speed

[long jewel]

yes it has a tick()

That moveTo method is just going to be a starter

The NPC implements a Navigator class

ignore tickRate

[long jewel]

Ohh yes

Good idea

[grim iris]

or if you want to do fancy yaw and pitch angles

[long jewel]

cause it does slide a lil at the end

[grim iris]

double xDiff = targetLocation.getX() - entityLocation.getX();
double yDiff = targetLocation.getY() - entityLocation.getY();   
double zDiff = targetLocation.getZ() - entityLocation.getZ();

double distanceXZ = Math.sqrt(xDiff * xDiff + zDiff * zDiff);
double distanceY = Math.sqrt(distanceXZ * distanceXZ + yDiff * yDiff);
double newPitch = Math.acos(yDiff / distanceY) * 180 / Math.PI - 90;
double newYaw = (Math.atan2(zDiff, xDiff) * 180 / Math.PI) - 90;

[long jewel]

yeah i need to figure out yaw and pitch

i need a naw before i do tho xD

[grim iris]

sleep is for the weak

[gilded skiff]

@long jewel are you still using Pathetic - or are you just using this vector stuff to walk places

cause it would probably be quite easy to use this now for the points you get from pathetic

[long jewel]

currently just pointing NPC to walk to location

I need to build up a whole system for this

pathetic is the end goal

but i need to handle a bunch of shit first manually

[gilded skiff]

sounds fun :)))

[long jewel]

#help-development message

saving that in here

[grim iris]

💀

[long jewel]

its a lie

theres no colllide() method

oh

collideBoundingBox?

wait no thats not block collisions

[grim iris]

might be a paper method

[long jewel]

ah

checkInsideBlocks

nice mojang

[grim iris]

that's not really the mojang method you're looking for

I'll just paste code for the fake-block zombie collision stuff I made on 1.18.1

https://sourceb.in/BJAmWadsHx

[long jewel]

oh okay, thought there was just a universal method for collisions ngl xD

hooooly

ahh

it uses so much paper :((

okay fuck it

imma scratch all this shit

and just make a zombie, but send packets to make it apply as a player

cba with this math shit

[grim iris]

you know you can just copypaste paper's methods and change them

collision is kinda specific

but it starts by grabbing the entity's aabb and shifting it by the velocity vector

then grabs that new AABB and checks for blocks based on their known hitbox

if it's air, it don't care

if it's a known full block, it makes a full block hitbox

otherwise it checks for fancy shapes

[long jewel]

thing is i have no idea what AABB is

My brain can barely handle subtracting 2 vectors and multiplying + dividing the result xD

Especially once shapes like end rods are involved :c

Not to mention this isnt event a real entity

so it just makes everything so much harder lmao

[grim iris]

AABB is an AxisAlignedBoundingBox

basically a 3d box that can do collision

[long jewel]

yeah thing is, with a fake ServerPlayer it wouldnt even have one tho, since its not actually spawned in the world

it doesnt exist server side

[grim iris]

an aabb is just an object

it doesn't care about the entity behind it

you can make aabbs whatever size you want

this is a shitty 2d representation of an aabb

the arrow and "x" indicator are an example of a collision

[long jewel]

Is there a NMS method for getting a specific entities AAB or is it shit i gotta make myself

[grim iris]

where you can check for exact collision spots given an incoming vector

[grim iris]

getBoundingBox();

[long jewel]

ahh

[long jewel]

Wait AABB has direct checking methods ?

[grim iris]

not really but it has basic ray tracing iirc

you can expand and contract the box

and its scale will always be the same

I mean if you contract only in a certain axis it won't

[long jewel]

I couldnt just use contains on a positional vector on the targets AABB?

Or i gotta do all this complex shit

[grim iris]

ehh not really

you gotta do complex shit

[long jewel]

Dang :/ probably explains why no client sided server player or entity library exists lmao

Well ty for explaining it to me, its way out of my league math wise, I didn't even pass basic algebra in HS lmfao

[long jewel]

https://github.com/hakan-krgn/hCore

i stand corrected

some giga chad did make one

[grim iris]

math is fun

I hate the HS topics but rest is fine

[long jewel]

It really does seem fun but, my brain cant handle it

Yet i can handle 20 different threads at a time while throwing them back onto main for a quick method call then yanking them back async all over the place

kinda of amazing i made it as far as i did without any math

[grim iris]

I mean

I failed trig in math class yet I'm still making particle effects

brains are weird

[long jewel]

Ngl im could probably manage together particles

Seems a tad bit easier than doing collisions based on the code i saw

[long jewel]

i got this but

[grim iris]

Looks accurate

[grim iris]

did you do that re-syncing?

[long jewel]

wym re-syncing?

[grim iris]

sending a teleport packet on the start and finish

to resync the entity position with what the palyer sees

[long jewel]

i do send it at the very last position but

i dont notice it

its in that vid

for some reason pathfinding it putting blocks in air

i idnt do collisions btw

i just set the entity to walk on the pathfinder

[grim iris]

oh fun

well

I'm not gonna look into it for now

got out of bed at 5am to setup a minigame map

[long jewel]

ouff xD

[grim iris]

because my homie hasn't set it up for the past 2 weeks

[long jewel]

nah i was just sharing what i had done xD

[long jewel]

lazy ass

2 weeks?

[grim iris]

yeh

[grim iris]

but hey it was a very productive 2 weeks

got a lil clip

[long jewel]

waayment

Is this for the NRK?

They had a dev working on the same thing a while back 🤔

[grim iris]

idek what the nrk is

this is just a side project I picked up for a server like a month or two ago

[long jewel]

ahh

NRK Is another server, i know a fwe devs from it and they legit asked for the exact same type of game mode ahaha xD

[grim iris]

ehh

this is like

95% from scratch

[long jewel]

oh yeah no doubt, just simnilar idea they wanted

[grim iris]

only external plugins I couldn't bother to remake were tab, corpses and protocollib

[long jewel]

FINALLY

NO MATH

NO BULLSHIT

i just need to lock the pathfinder to lowest y

[grim iris]

That's a bit goofy

Zig zagging