Question Netcode: Proper way to make an "Offline" bootstrap and add networked systems later?

First I'd like to ask again if it would be possible to create a Netcode subforum like DOTS physics and DOTS animation has. Really helps organizing all the knowledge in one spot
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Now my question: I am making a game that plays offline by default, but there is an online mode. So I need the Netcode package in my project, but I don't want it to affect the default systems in my game

I have read this section on the subject and copied the "ExampleBootstrap" in my project. However, this doesn't seem to totally work in my case, because I still see a lot of netcode-only systems/groups being created and I get NullReferenceExceptions in PhysicsWorldHistory at this highlighted line (I guess because the Client/Server simulation groups creation was prevented):

And see how there are still tons of netcode-related systems being created in the default world:


What makes certain Netcode system still be created with the "offline bootstrap" approach and others not?

 

Hi,
First +1 on the sub forum.

Regarding the actual question I have no idea but for a game that is both online and offline my first though would have been to make the game using netcode as an online game and for the offline mode make it "locally" online.
I remember unity videos showcasing the netcode package were they showed several modes including ones that made the client and server world run on the same machine bypassing the transport layer.

So instead of trying to "get out" of the netcode system would it not be better to work with them ?
Would that not avoid code duplication/complexity of managing both modes ?

 

I am also curious about how to do this.

I agree with this approach. "Client World" systems that you don't want to run when running the game in offline mode could check if a Server World and Client World exist and exit early if they are not in the server world.

 

actually that's a very valid point and I think you're right that it's better to work with network systems all the time

 

It's a win on the subforum finally

 

So, even though I agree that I should code my singleplayer systems with netcode systems in mind, I'll still need to create my client and server worlds at runtime. I think everything would be fine if it weren't for PhysicsWorldHistory spamming errors whenever ServerSimulationSystemGroup and ClientSimulationSystemGroup aren't yet created

Error happens on this line:


Is PhysicsWorldHistory missing null checks, or is it me who's missing something?

 

Understood.

I copied the ExampleBootstrap shown here and it gave me the PhysicsWorldHistory error, but I think what I didn't understand from that page was that it's also necessary to create Client and Server worlds right away for an "offline" mode

 

Took me quite a while to figure out why my subscene wasn't rendering in the client world even thought it was loaded.
Turned out it had something to do with the systems in the default world I had included all systems there too, which is wrong I guess.
Might be worth adding a note about 'ExplicitDefaultWorldSystems' in the bootstrap docs and it's importance, I would have never figured it out without this thread.

Personally I feel that the 'automatic' finding of systems is a big ol smell.
I have always struggled with programming techniques that involve reflective black magic, e.g. annotations.
I'm not sure how to solve this, I know that there is a certain amount of 'automatic' that you want with an engine but not being able to understand why something is happening is the Achilles heel of a programmer.

Anyway, this was just feedback from a noob

 

@CMarastoni Is there any plan to remove default world in next Netcode package or in future? But ConvertToClientServerEntity monobehavior still needs to work properly after this changes.