DOTS and 2021.2 known issues

I know about the notice on compatibility, but out of pure curiosity I've opened my big project in 2021.2 and everything seems to be working just fine. I also found in the release notes many mentions of Burst-related DOTS runtime fixes.

I am now wondering, has anyone stumbled upon any showstopper issue with DOTS on 2021.2 ? And what was it?

I have yet to test on consoles, but right now it doesn't seem like there's anything "not working" in Entities on 2021.2. It is in fact the smoothest Unity upgrade I did in years.

 

Interesting, keep us posted, I asked some time ago in Discord about higher versions but haven't got any good answers. I witnessed the same thing in 2021.1. It was working but haven't continued using it.

I plan to upgrade myself for some time, 2020.3 is not a good version as I've posted often enough now. 2021.1 and 2 have some great improvements.

 

Just tried updating my project and got

basically appears to be the same as reported here https://forum.unity.com/threads/19a-datawatchservice.1120459/

Fairly certain animation wont work without a new package release

 

Yeah was about to say i don't think animation package works.

I've been using 2021.2b6 (I think i had some problems with b10 so I downgraded and haven't bothered upgrading since) for some libraries that won't be released for a while. Mostly because I wanted the upgraded uitoolkit runtime stuff.

Yeah so this is just a weird practice by Unity atm. They including changes to the burst package in the release notes. You'll notice most (all?) of those fixes are in the burst changelog and exist in previous versions of Unity as well.

 

Tested my project in Unity 2021.2.0a12 as I don't have any other version installed currently.
Got this error: https://forum.unity.com/threads/upg...reaks-projects-using-entities-0-17-0.1085774/
Posted fix doesn't work so I just uncommented this part. Compilation works then.

Everything seems to work fine in editor. Also the Build runs stable.

Who uses the animation package? lol, seriously.

I'm mainly interested in Burst, jobs and Entities. All seem to be compatible with newer Unity version. Not only is the communication a joke, even what IS communicated is one.
There's a big difference of really unusable experimental packages being incompatible or EVERYTHING.

So, not to make it sound like I'm angry about this. I'm quite happy that I can use a newer Unity version again!

 

If I remember correctly, the reason why I didnt move to 2021.2 myself was that Entities and UI Toolkit (the built in one in the new stable version) does not work together. Some assembly definition issue that even plagues 2020.3 occasionally.

Burst and Jobs (and Collections) are all moving lockstep with even the Alpha build so there's no issue there.

 

Actually entities, UI toolkit and input system seem to work perfectly together in 2021.2 now, which is why I moved some experimental libraries to it.

 

@tertle Can you take a look at the Entities DOTS editor and see if you can open DynamicBuffers? I can open the list of buffer items but then I can't open buffer items itself.
Also the hover from the entities itself in the overview seems missing.
I'm using the latest version now, 2021.2.0b16.

 

Seems fine? Though a bit different from 2020.3

 

Thanks, @tertle. I have Odin installed, maybe that's interfering.

 

I don't have this issue in 2021.1.25f1, must be UIToolkit related I guess.

 

That's amazing guys!
Thanks for sharing these news I'm very interested in using new URP stuff which are only available in unity 2021.1+
I'll try the new unity versions with DOTS and hope to not encounter weird bugs.

 

This is all great news - pls continue to report your findings - and @UnityOfficials if you plan(or what ever that plan is) to add dots support to current / future LTS unity versions only please say so - break this inexplicable silence

 

Does Hybrid renderer work in 2021? Last time I tried I couldn't fix the errors or when I did nothing was rendered (it had something to do with SRP batcher)

 

I've been using Entities 0.16/0.17 + HDRP + HRv2 with Unity 2021.2.0b14 without any major issues. The biggest problem was ensuring that all shaders/materials used in subscenes are compatible with HRv2. There seems to be a bug that if any shaders are incompatible, rendering breaks completely and the entire scene becomes one giant rendering artifact. This includes the error shader, which means that my entire scene keeps blinking in and out of existence while shaders are compiling. Oh well. I can live with that for now, though.

If you need to fix your scenes, the warnings logged in the console are useful for finding offending materials.

One other issue I have is that (some? all?) lights from subscenes don't seem to render in build - still need to investigate that though, could be my own fault.

(Not actually sure if any of those problems are 2021-specific)

 

@Enzi I am having the same issue with and without Odin. Some buffers are already expanded and others are not. And expand button is greyed out. @tertle Did you try with a component that has multiple fields?

 

in my case, I use my own hybrid renderer which is more suited to my Game Style (TOP DOWN).
Additionally, it looks like Unity is focusing more on DOTS in its hybrid renderer than actual performance.
one of the reasons I said this is:
they do Frustum Culling using DOTS (CPU), which leads to useless data transfer of survived renderers from CPU to GPU on every frame.

 

I read discord(unity / dots) some dev ported his project(dots) to 2022.1 and it works - i tried 2021.2 (simple urp - dots app) and it works except that when i exit unity it crashes for some reason otherwise it works fine (maybe problem is in materials as above in some posts is reported)

 

@MartinGram @Joachim_Ante

Half a year later, do we know if we still should stick to 2020.3 LTS when using DOTS? Our current tests show nothing wrong with using the runtimes on 2021.2, the only thing holding us back is the unfamous notice on compatibility.

We'd like to have FidelityX / DLSS, but more importantly Skinned Mesh support for VFX graph. These only are available in 2021 tech stream. Our game has been delayed to Q3-Q4 2022 and we wonder if we could safely jump to 2021.2 or not.

If you can't say anything, when should we expect news? This year? Early next year? Still undetermined?

Any update would be greatly appreciated.

 

We just tried updating to 2021.2 on a separate copy of our project that uses a mix of classic GameObjects and Entities. Things work ok in the editor but there are AOT errors with the Entities package in the Windows build (x64, IL2CPP). I'd recommend trying to upgrade on a copy of your project. But be warned that it will most likely fail, if not in the editor then almost certainly in a build.

 

What if you don't use IL2CPP? I didn't see anyone else mentioning it before.

 

yes...everything is ok, include il2cpp, but we use entity & physics package (query) only. Hybrid renderer v2 is broken and low performance.

 

We have no such error and things are working fine on Windows 64 and Mac (Intel and Silicon). Our project is big (~300 gb of data) but uses nothing else than Entities (no Hybrid Renderer, no DOTS animation or physics). Still, we haven't tried on console and I'd also advice trying with a copy of your project (or a project with version control like ours).

 

Was that using IL2CPP?

I've had issues building with IL2CPP - the game seemingly compiles correctly, but some of the subscene files are missing/corrupted when the player launches. I'm sticking to Mono builds for the near future, these seem to work just fine.

 

Yes but I do not use subscenes so that may explain it

 

It is definitely possible that the method throwing up AOT errors is actually defined in the Hybrid Rendering package as an extension method. Unfortunately we do need Hybrid Rendering so we'll probably just wait for things to be fixed

 

Just updated to 2022.1.15a and Unity.Rendering seems to be missing along with RenderMeshDescription and RenderMeshUtility.
It was working until a13 (ECS + HR2 + very little of Physics)

 

Fascinating. This is just me reading tea leaves, but it certainly suggests something new and different is going to be replacing hybrid rendering.

 

According to this, there is a new hybrid renderer coming: https://github.com/Unity-Technologies/Graphics/pull/5842

 

Oh, this is a most interesting find, sir!

Spoiler: must read

Technical changes

• Hybrid Renderer V1 has been completely removed, and ifdefs related to it have been removed. The name "Hybrid V2" is also removed. Going forwards, there will only be a single Hybrid Renderer (the third version, but not called "V3").
• Shader macros have been refactored to eliminate the workaround for a bug in the fxc preprocessor. The new macros are simpler and easier to use as a result, and will only work with the new caching preprocessor which is nowadays enabled by default.
• A number of built-in shader properties in DOTS instancing variants have been migrated from DOTS instanced properties to efficiently encoded constant buffer constants set up by dedicated SRP Batcher C++ code. This saves a significant amount of GPU memory and should also be faster.
• The DOTS instancing metadata constant naming format has been changed to avoid double underscores occurring. This fixes a problem on Nintendo Switch which emits compiler warnings when such names are encountered.
• The UnityPerDraw cbuffer is not defined anymore with the DOTS_INSTANCING_ON variant. BatchRendererGroup doesn't need it anymore and it's not even bound.
• Fixed shader compilation errors related to previous matrix definitions with the DOTS_INSTANCING_ON variant. Hybrid Renderer had not support for Unity 2021 and the Hybrid Renderer/SRP CI has been disabled for the whole 2021 cycle. It comes at no surprise that the DOTS variant was broken at some point, so we fixed that.
• Enabled LOD fade variants for DOTS instanced HDRP Shader Graphs, for which they were disabled. BatchRendererGroup is now able to support it, and a future version of Hybrid Renderer will implement it (but does not currently do so).

 

Interesting, I hope we get to test it in the very near future.


I wonder why are they still calling it "hybrid" rendering. The idea of a fully DOTS (and thus "pure") game is quite silly to begin with.
What would be the point in making a "DOTS main menu", "DOTS settings menu", "DOTS <insert any silly non-gameplay related component that any game must have>". Game objects rendering some things here and there won't go away even in a heavy ECS/DOTS game.

 

Because it still uses mesh and material. A pure implementation would do away with these.

As per your menu, well if you use uitoolkit you don't use game objects for your ui either (except the base document file)

 

What? rendering without a mesh and without a material is pretty much not rendering at all. The only thing that may comply with that statement of yours is maybe mesh shaders with no textures?

Rendering is rendering, it doesn't matter if the programmer/developer "sees" it as a mesh and material in a game object or as a mesh and material in an "entity". Some engine internal code to handle gpu upload, etc might be different between them but it is still fundamentally the same logic, cull, batch, upload, render.

 

He's referring the "Material" and the "Mesh". Those are managed classes.

Its true that those can be represented differently, but that requires custom editor logic and engine changes.

 

Which is probably why this mystery incompatibility is happening right now, although that don't really explain why they need to keep it a secret...