Clientside prediciton

[Ebisu]

To what I understand, the NetQuake and QuakeWorld clients predict movements beforehand in order to reduce latency issues with 90's tier internet. In the modern day that is a horrible idea when playing with people from the other side of the globe. Has there ever been an alternative client to NetQuake/QuakeWorld that doesn't behave this way? I could be wrong about this, but I'm almost certain that's how this works.

[golden_boy]

Only Quakeworld does prediction.

[smokey]

This may be a dumb question but if clientside prediction is possible why is it not possible to have everyone on a quakeworld/quakelive server play with 0 ping? would it be too strenuous keeping track of new players joining that are high ping (100-150) while the rest of the server has 20-50? Just curious .

[Spike]

prediction just moves the latency to where its less noticable, you can't remove it.
Its a fundamental law of physics. Signals from one side of the planet require time to travel to the other side.
some quakeworld servers have 'antilag' enabled. Really it just moves everyone back in time so your shots hit what you saw when you fired. Instead of missing, players now potentially get shot through walls, and it can still take a while before the player knows they got shot.

[Cobalt]

I believe DP does it as well because its a hybrid of stuff from QW and NQ. There is a command cl_movement in DP and some variants of it that will disable client or server prediction.

Only Quakeworld does prediction.

[Mindf!3ldzX]

prediction just moves the latency to where its less noticable, you can't remove it.
Its a fundamental law of physics. Signals from one side of the planet require time to travel to the other side.
some quakeworld servers have 'antilag' enabled. Really it just moves everyone back in time so your shots hit what you saw when you fired. Instead of missing, players now potentially get shot through walls, and it can still take a while before the player knows they got shot.

that's so ridiculous lol I have never seen a more blatant / blunt explanation given, and anytime I need a point of reference for explaining prediction, I'll be referring them here to your post.

[Ebisu]

Thanks for the response guys. Somebody brought it up and I felt the drive to inquire, because you guys seem to know EVERYTHING about this game.

[R00k]

DarkPlaces and FTE have better prediction than stock QW.

cl_movement is clientside prediction, but requires connecting to a DP7-protocol compatible server.

smokey even on a lan your ping isnt going to be 0.

[MadGypsy]

@zero latency is impossible

What about the N64 way of doing DM, splitscreen on one system, is there a latency there as well? I could come up with guess-answers that go either way so, what's the not guessing answer?

[Cobalt]

In that system network transmission latency will be nearly zero because the network line would be a system buss and whatever speed that runs at would be the latency. It boils down to the transistors inside the chips. A transistor thats conducting a circuit is considered "on" or (1) in binary sense, and one thats not is considered "off" or (0) in binary sense. The latency boils down to how fast the transistor can switch states from 1 to 0 and vice versa.

Add all these transistors up at a hardware level from user input, through the buss, to the CPU, cpu calc time to perform result, then display results through monitor and you wind up with probably < 1mS in a state of the art system these days, but its still consifered latency.

@zero latency is impossible

What about the N64 way of doing DM, splitscreen on one system, is there a latency there as well? I could come up with guess-answers that go either way so, what's the not guessing answer?

[MadGypsy]

@cobalt

That is a more technical explanation of the gist of what I figured. I really should Invest some time in having a better understanding of how computers work. I was programming in basic out of nerdzines when I was 8, but here I am 40 and I couldn't tell you what a serial bus actually is or does. Maybe that's sad idk... I never really had an interest in computer hardware and how it all works together to complete the whole.

Hah, I just realized I am so old that, when I first started programming you had to actually write line numbers...lol

remember this?

10 print YourName
20 goto 10
>run

if you do you are oooold. LOL! Unless this offends you, then you are the only one that is not the oooold.

you = you reading this / not specifically @Cobalt

My first hard drive partition was on an audio cassette

[Cobalt]

@ Gypsy, yea Im 50 now but know exactly what you say.

Serial merely means "sequential" or "in order". The old serial printers and floppy on the Commodore 64 used serial interfaces, it just means there is (1) data line and the info it transmitted thru it in a series of 1's and 0's that are read in order of reciept at the other end and reconstructed into the 8 bit data format. Parallel means you have [8] lines not 1, so you merely set those lines to represent the ecact binary 8 bit number you want to transmit, and the other side also has 8 lines and there is no need to wait for the sequence to complete as in serial, its read immediately.

[Spike]

@cobalt
while network latency does work out to be about 0.1ms on a lan, there are other considerations at work. Games are typically designed to be playable over the internet without problems. as a result, they throttle themselves to between 30-77 packets per second (quake2 was 10 packets per second...) as a result, the peer is not allowed to respond as soon as it gets a packet (and if its single-threaded it additionally has to wait for the video code to finish doing its thing). this means that there's a 13ms minimum latency in games like quakeworld.
1000/77 = about 13ms

of course, there's other sources of latency that are impossible to measure. like mouse/keyboard polling interval (yes, USB depends upon polling), this is typically about 60hz (17ms / 2).
There's also graphics rendering times, including vsync, which can vary quite a bit. plus with lcd screens, there's an additional 'response' delay time. these can vary quite a bit.

All these mean that a lan isn't really that much better than a short hop to a nearby internet server, and that games that claim a 0/1ms latency are basically lying about it.

Long story short, trying to remove the last 13ms of your ping is basically pointless as its just social engineering rather than actual productive effort.
Of course, social engineering can be productive too, but for all the wrong reasons.

[MadGypsy]

someone needs to create earlyancy.

Unrelated sorta:

I was thinking about my last post and I was reminded of my first "tablet". I found one on ebay for 14 bucks so I threw my bid in the ring. What do you think the latency on this thing is? lol



Believe it or not I made a movie on this thing out of animated dots, various beeps and scrolling text. I'm not saying my movie was good but, I totally made one. I was (40 - age of device) 10 or something.

[Ebisu]

1000/77 = about 13ms

of course, there's other sources of latency that are impossible to measure. like mouse/keyboard polling interval (yes, USB depends upon polling), this is typically about 60hz (17ms / 2).
There's also graphics rendering times, including vsync, which can vary quite a bit. plus with lcd screens, there's an additional 'response' delay time. these can vary quite a bit.

What kind of numbers are we looking at with a good CRT, and a PS/2 keyboard and mouse, and no VSYNC? No real reason of importance, but I was just wondering.