• Announcements

    • khawk

      Download the Game Design and Indie Game Marketing Freebook   07/19/17

      GameDev.net and CRC Press have teamed up to bring a free ebook of content curated from top titles published by CRC Press. The freebook, Practices of Game Design & Indie Game Marketing, includes chapters from The Art of Game Design: A Book of Lenses, A Practical Guide to Indie Game Marketing, and An Architectural Approach to Level Design. The GameDev.net FreeBook is relevant to game designers, developers, and those interested in learning more about the challenges in game development. We know game development can be a tough discipline and business, so we picked several chapters from CRC Press titles that we thought would be of interest to you, the GameDev.net audience, in your journey to design, develop, and market your next game. The free ebook is available through CRC Press by clicking here. The Curated Books The Art of Game Design: A Book of Lenses, Second Edition, by Jesse Schell Presents 100+ sets of questions, or different lenses, for viewing a game’s design, encompassing diverse fields such as psychology, architecture, music, film, software engineering, theme park design, mathematics, anthropology, and more. Written by one of the world's top game designers, this book describes the deepest and most fundamental principles of game design, demonstrating how tactics used in board, card, and athletic games also work in video games. It provides practical instruction on creating world-class games that will be played again and again. View it here. A Practical Guide to Indie Game Marketing, by Joel Dreskin Marketing is an essential but too frequently overlooked or minimized component of the release plan for indie games. A Practical Guide to Indie Game Marketing provides you with the tools needed to build visibility and sell your indie games. With special focus on those developers with small budgets and limited staff and resources, this book is packed with tangible recommendations and techniques that you can put to use immediately. As a seasoned professional of the indie game arena, author Joel Dreskin gives you insight into practical, real-world experiences of marketing numerous successful games and also provides stories of the failures. View it here. An Architectural Approach to Level Design This is one of the first books to integrate architectural and spatial design theory with the field of level design. The book presents architectural techniques and theories for level designers to use in their own work. It connects architecture and level design in different ways that address the practical elements of how designers construct space and the experiential elements of how and why humans interact with this space. Throughout the text, readers learn skills for spatial layout, evoking emotion through gamespaces, and creating better levels through architectural theory. View it here. Learn more and download the ebook by clicking here. Did you know? GameDev.net and CRC Press also recently teamed up to bring GDNet+ Members up to a 20% discount on all CRC Press books. Learn more about this and other benefits here.
Sign in to follow this  
Followers 0
fjholmstrom

Where to put the jitter buffer

4 posts in this topic

So, I have been working on my networking code more and more, and to be honest it's starting to look pretty nicely :). But, enough talk... my question is pretty straight. When implementing a jitter buffer, where in the packet delivery chain is common place to put it? I see a few different options:

  1. You apply the jitter buffer to the entire packet "receive" mechanism, basically buffering each packet as it comes in and then hands it out at the proper interval to the rest of the code.
  2. Since some data might be time critical, you put the jitter buffer "after" the packet receive mechanism and move it to the specific parts of the application that need the buffering - for example rendering of positions.

Also is it common place to use a jitter buffer on both ends of the connection (server and client), or do you usually just run it on one (the client I would guess) ?

0

Share this post


Link to post
Share on other sites
The sender typically just sends as soon as possible. Additional latency there just adds latency, without any real help against jitter.

You may decide that "time critical" packets are delivered on receipt, rather than de-jittered. The question is then: What will the experience be when you actually have jitter, and those "time critical" packets are delivered with some delay (say, exactly the delay of your de-jitter buffer.) If the game is still a fine experience, then why not de-jitter everything all the time, if the game is still fun and the code simpler? There may be cases where instant delivery on receipt actually on average makes the game better; in that case, that might be a fine optimization to implement.
0

Share this post


Link to post
Share on other sites
The sender typically just sends as soon as possible. Additional latency there just adds latency, without any real help against jitter.

 

Ah yes, maybe I was not clear - assuming a Client/Server model, is it common place to de-jitter things sent form the server to the client and also de-jitter things sent from the clients to the server. Or is it usually just applied in one direction? I would assume both.

 

 

You may decide that "time critical" packets are delivered on receipt, rather than de-jittered. The question is then: What will the experience be when you actually have jitter, and those "time critical" packets are delivered with some delay (say, exactly the delay of your de-jitter buffer.) If the game is still a fine experience, then why not de-jitter everything all the time, if the game is still fun and the code simpler? There may be cases where instant delivery on receipt actually on average makes the game better; in that case, that might be a fine optimization to implement.

 

As always a very good point, and I'm leaning towards putting the entire packet in a jitter-buffer, as it just makes the entire code easier and cleaner (like you say). Also I worry about actually untangling what *can* be delivered instantly and what has to be de-jittered, it just seems like it would lead to a slew of possible de-sync issues and weird behavior.

0

Share this post


Link to post
Share on other sites

Are you sure you need this? I would try not to add any more latency than the network already has, because that could make the game feel even more laggy than a few packets arriving a bit later. Maybe you could just let it through as fast as possible and when the client receives corrections from the server apply them gradually other a bit of time so the player sees no "teleporting".

0

Share this post


Link to post
Share on other sites
It has been my experience that a game that has rock-solid, predictable latency with no jitter is considered less "laggy" than games where things sometimes work, and sometimes not.

For example, I think the Halo series use 100 millisecond network ticks (perhaps 67 milliseconds, it's been a while) which means they pack 6 simulation ticks into each packet out the gate. This adds latency. Yet, the game series is considered a very well playing FPS :-)
1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0