Use DOTS with multiplayer

Hi,

I'm having lots of troubles with DOTS. I find it already hard to find good tutorial to use it. I'm trying to make a simulation like game. So there is lots of objects and i'd like to use DOTS for better performance. But in the same time, Unity upgraded it's multiplayer api (Now MLAPI) and i can't find any way to use them both.

Does anyone have a idea?

 

DOTS has its own multiplayer package called NetCode

https://forum.unity.com/forums/dots-netcode.425/

 

@miyoku As tertle said NetCode is Unity's newest multiplayer system and it runs entirely within ECS. I've played with it a bit.

Few things to watch out for.

1. It is a bit finicky. You have to use 2020.1.9+ and Standard Renderer. URP is not supported yet since it uses multiple worlds and then your rendering gets all messed up.

2. It's a bit confusing if you are newer to DOTS. To set up networking components, you'll add a tag to an entity which will then execute some information against a entity (like adding a proper component) and then destroy the tag.

3. It is very barebones. Since it is new, it doesn't have a ton of nice to have things. But the core is there and very good.

Here is a post about some of the things that the base tutorial isn't up to date (and I think how to fix them). And you'll see some of the issues I ran into.

https://forum.unity.com/threads/is-the-getting-started-in-the-doc-updated.1106816/#post-7128899

This is another great really in depth tutorial (other than Unity's standard one) but it is looooooong.

https://moetsi.gitbook.io/unity-dots-multiplayer-xr-sample-project/dots-netcode/overview

 

Can you explain a little more about this? I made a test game with DOTS Netcode and both URP and HDRP (separately) and didn't notice issues

 

@PhilSA I read somewhere that URP can't render multiple worlds (since the server and the client sets them up) and that was causing issues where no entities would appear. It was my first attempt to set up DOTS Netcode and lots of stuff went wrong so maybe URP works okay.

I think I had Unity 2021 as well, which may have been the cause of not being able to use URP. But I am not sure.

I can't find where I found the info that URP doesn't support multiple ECS worlds. So maybe I imagined it.

 

I see, in my project I skipped the whole "test multiple client/servers in editor" feature, so that could be why I never noticed the issue. Basically, I only ever tried playing with one world active at a time (either just server, or just client, or client+server in same world)

 

Ahh, well that makes me feel better. Every time you create a fake client, it creates another world. You can flip through them too which is pretty cool for testing.

 

I did try using just one client + server as well, and was having major problems. There is a post around here somewhere about URP not working well with multiple ECS worlds. But if you can get it working with lots of ECS worlds, I would be pumped!

 

Actually wait, I just checked again and I do get multiple worlds at the same time (I was misremembering). But what's peculiar is that it looks like My ClientWorld and ServerWorld are "linked" to the DefaultWorld somehow? Notice how the Server/Client groups are also in DefaultWorld, and the systems in Server/ClientWorlds have a "(Default World)" at the end of their name

No idea what's going on here honestly, but it appears to be working

Default World


Client World


Server World

 

Well that is great. Things are working dandy right now with the Build-In Shader so I am going to keep that but I'll definitely switch to URP at some point in the future.

I am still pretty new to this version of ECS so maybe I messed something up here. Last time I looked at it was 0.4 and the URP was still LWRP.

 

Is URP fixed with dots?
it is 2023 and I don't understand if URP support for Dots are there.

 

I am pretty sure URP is the only way to do ECS graphics.

 

HDRP as well

 

Oh good, I am glad they have put that in. I haven't been following ECS as closely as I had before.

 

Öhm what is ECS graphic?

 

Source: https://docs.unity3d.com/Packages/com.unity.entities.graphics@1.0/manual/index.html