Sign in to follow this  

Component object model and networking architecture.

Recommended Posts

Semei    123

So after all those dedicated posts about Component object model i decided to use that into my game, utilizing Artemis.Net.

Now, about networking it is unclear, on how i should properly integrate that, without messing up my components/systems.


I'm planning to use Authorative server model.


So basically from what i understand, i would have an 'agreed' clean/begining state of objects in both server and client. Then, when a component from any of entity updates, it is marked 'dirty' and is added to some sort of queue 'send list'. Or when it is needed to create new entity, a 'create this entity from this template' type of message is sent.


What is unclear, is how to properly implement this right from the start, so i have a nice system to work with, that i will not have to change later. Where do i store the 'dirty' flag? In each component? How do i manage different versions/generations of entity?


How do i manage cycles or behaviours, that are consistent and depend on system? For example, if i have circle on ground, that changes its color to,say, red, if player steps on it, and continues to pulse and change its behaviour, depending on color. I would have a 'Pulsates' component in entity, that has property like 'isPulsating' and 'currentPulseColor', that would change every frame. But i dont want to send pulsating color every frame, if i know, that if i had a message update of 'isPulsating', i can calculate pulsating color just from that, i dont need updates on pulsating color every frame from server. How do i manage and distinguish between things like 'isPulsating' and 'currentPulseColor'? And then again, i would sometimes need to know everything, for example, if the circle was not in range, and then becomes visible, i dont know for how much long it had been pusating and therefore cant calculate its color, and i need that data...



hplus0603 Had a little insight into this a while a go, could you maybe help me with this? biggrin.png


Edited by Shuun

Share this post

Link to post
Share on other sites
Angus Hollands    869

I am basing my own system off Unreal's architecture. I've decided that the networking aspect should be as separated from the objects themselves. Firstly, it is important to make a distinction between "objects" and networked class instances. My concept; and thus that of unreal is to have network class instances that may have physical meshes etc.

Anyway, They way I manage data for different clients is to have "ReplicationChannels". Here's my document


Essentially there is a channel created on the server and client for every object that exists multiplied by the number of connected peers. Then we can save the state of networked attributes on the channel. I use a form of hashing to determine if the value has changed, to avoid issues with muteable types. I use descriptors in python to set a dirty flag when an attribute is changed but that's part of the bIsDirty variable that Unreal uses and so I still compare the custom hash of each value when I ask the channels to replicate data.

I'm happy to tell you more about what I'm doing. It's interesting as I am coming from the other end; adding a component framework after creating a replication system. However, in my situation I shall be using a more system-based approach. (it's sort of a hybrid, as attributes (things that are sent over the network) can be instances of classes and therefore treated like components or they may be fundamental data types.. 

Edited by Angus Hollands

Share this post

Link to post
Share on other sites
DrSuperSocks    258

In my game engine, networked objects are instantiated on both the client and the server, and components instantiated on either side can send messages to each other. Other than that, all packets are processed by the active game state. I'm currently trying to refine my networking and look for better methods, as I'm still pretty novice at network programming.

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