How does half-life construct multiplayer messages. For instance, rummaging through the crossbow code there is no direct code there that shows that, "oh yes, here is the fire function and here in the NetworkGuy->SendMessage( BAM )" Of course it is extrapolated out, but how does the engine determine what data is even needed to be sent out over the wire? All non-static data that has changed since last frame? And since I'm going to be digging through a few engines to get the general feel as to how message handling is done, anyone want to point out something worth viewing in a given engine? or articles or whatever else? One more thing, after reading 'how pluggable factories rock my m/p world', and comparing this to the half-life network setup of not-so-visible network structs or messages. Is there a junction between the two? A question not so far off from my original. But continued input in relation to this article is appreciated. Much thanks,_> ^sf.

Look for the MESSAGE_BEGIN and MESSAGE_END macros, with the MESSAGE_XXX in between. They inject the code that wraps / sends the appropriate bytes to the client.

But you don't find these during Fire() or spawning of other weapon projectiles, like the crossbow bolt.