Official Notice on DOTS compatibility with Unity 2021.1

Hi!

With the release of Unity 2021.1, DOTS is at a crossroads in terms of compatibility with the currently available Unity versions.

While certain parts of the DOTS ecosystem (Burst, Jobs, Math, Collections) are compatible with the 2021.1 TECH stream, other packages such as the entire entities suite is not.

For your projects there are now two upgrade scenarios depending on your use of DOTS packages.

Scenario A - My project is not using entities based packages

You will find that the Burst package and its accompanying packages are visible and present in the package management system, and you can continue to upgrade into the 2021 tech stream of updates.

Scenario B - My project is using entities based packages

You must stay on Unity 2020 LTS and on Entities 0.17 for now. Future releases of Entities will not be compatible with Unity 2021 until the end of the year at the earliest. Upgrading to 2021.1 and using current or future Entities packages will not work and is not expected to work.

As soon as we can, we will provide further information on how we will continue to develop and release Entities and Unity in lock step to provide a faster path of releasing DOTS to the Unity community.



I will leave the thread open for questions, but please understand that this is the information we can share at this point in time.

 

Thank you for the post and... OOooof.
Appreciate it's a complex set of interdependencies but are there particularly problematic areas some of us may be able to avoid (e.g. Hybrid Renderer) or is it pretty much everything ecs?

 

Will future Entities packages still be released, even though they won't be compatible with any available Unity version? Will we still be able to try them out in some form (or at least see their changelogs)?

 

How does 2021.2 factor into this?

 

The short answer here is that Burst and friends are considered production ready, where as entities and packages depending on entities are still considered to be in preview. With the way package management works from 2021.1, we have to have different ways of delivering Entities packages to our users.

 

Yes, Entities 0.18 is on its way.

 

We will expand on this specific point in the next posting we make on DOTS releases.

 

Should we expect new Entities releases to target 2020 LTS until 2021 compatibility is reached? Or are new releases going to be awkwardly incompatible with anything in the interim?

 

Appreciate there may be reasons you couldn't respond to the question more directly. I think we all understand Burst & Jobs are still good to use and understand Entities will be in preview for a long time yet. Over on the discord a number of us have no idea what delivering Entities packages differently means - any clarification possible?

 

Holy moly, time to downgrade when 0.18 comes then. In a strange way it's refreshing to hear you guys admit it's going to take longer

 

Hi @MartinGram. Can u make sure il2cpp build won't lauch game straight crash anymore in next Entities 0.18? If I remember correctly il2ccp crash bug exists starting from 0.13 or 0.14 something up until 0.17 still haven getting fix yet.

I believe this is related to subscene bug.
(Case 1311658) [Netcode][IL2CPP] Player build crash or not working properly
https://issuetracker.unity3d.com/is...on-null-pointer-dereference-when-launching-it
https://issuetracker.unity3d.com/is...ilds-crash-with-entities-and-netcode-packages
https://issuetracker.unity3d.com/is...rashes-when-running-x86-build-on-a-x64-system

I believe this is related to dots physics bug.
(Case 1315723) [IL2CPP][Physics][Netcode][Entities] Android build crash
https://issuetracker.unity3d.com/is...-crashes-on-signal-11-sigsegv-upon-app-launch

Hybrid Renderer bug
(Case 1327493) Error spamming when remove RenderMesh component at Authoring
https://issuetracker.unity3d.com/is...-rendermesh-component-is-removed-at-authoring

And also CompanionGameObjectUpdateTransformSystem and CompanionGameObjectUpdateSystem generating gc every frame. Can you make sure it will also getting fixed?

 

From my understanding, it sounds like 0.18 won't work in 2020LTS either? It's not clear

this statement sounds like it could mean we have to stay on 0.17, but it's unclear if that's what it was meant to mean or not

 

This actually poses quite a heavy challenge to overcome now. The latest unity alpha has just fixed a critical bug related to the HDRP compositor and ui workflow. My project heavily depends on both ECS as well as newer HDRP workflows. Sadly, the HDRP change required an editor based change (in 2021.2a12) which means I can't just use the hdrp package in LTS.

I however do not use any additive packages that depend on Entities. Physics, netcode, etc. are unnecessary for the project.

I have been able to build and run my project with the latest alpha, so I'm trying to rationalize why taking a step backward may be necessary on solely enities based projects.

 

Honestly this has to be one of the worst posts ever by Unity.

So entities 0.18 obviously runs on something.

And what that is, is the only useful/actionable information.

Of course you don't have to stay on entities 0.17 and LTS. There will be some version 0.18 runs on.

Or I guess they could just top this post off by releasing 0.18 against a Unity version nobody has access to. In a strangely twisted way that would actually fit.

You created this whole situation with packages. And now you don't know how to deal with it. You refuse to use accepted approaches because of some idea about protecting some segment of your user base from itself. But in practice that has only created confusion and created annoyances for most of us. This post is hilariously bad but it's just one in a long comedy of errors when it comes to packages.

 

Buried alive?

 

To clarify does this mean that future Entities, Netcode, Physics, etc. will continue to be released for 2020 LTS? Can we expect Entities 0.18 on 2020 LTS?

 

So it's impossible to have all the preview packages / features in a stable tech stream? This is too good!

Imagine If Unreal Engine 5 was missing an important preview feature that is only being developed in Unreal Engine 4.

So game developers who want to develop with bleeding edge technology are going to be missing entities, while LTS users who want stability will need to upgrade to the tech stream to fix critical graphics bugs with HDRP and URP?

 

In my opinion, #IPO . It looks bad when a bunch of script kiddies complain about unity not working when they install 10 experimental packages and have no idea what is wrong.

 

So what exactly am I losing, feature wise, by using 2020 LTS vs 2021 Tech stream, as an ECS programmer? Faster IL2CPP is one thing I know of. Anything else that would be pertinent for DOTS programming?

 

You can check out the release notes, but I was looking forward to some of C# 9 syntactic sugar.

But in general, DOTS people are the kind of people who love the new tech, so not being able to update for a year will hurt...

 

That’s a good question and ideally the announcement would have been clearer around this.

My reading is:
- ECS will be further developed behind closed doors with a non public unity version
- Public ECS development is limited to features compatible with LTS (possibly fine for testing API dev, etc with the wider user base)
- 2021 tech will be independent of ECS for the time being

Let’s hope they clarify and that it’s a good decision (even if not popular)

 

Just read this. We have actually upgraded to 2021 since last week and we did not encounter any problems. I guess we'll have to revert but this sucks.

 

To say this is a disappointment would be an understatement. DOTS was announced in 2018 to a lot of excitement and fanfare. Unity positioned it as the future of the platform, and a tectonic shift in architecture that could deliver 10x or even 100x performance improvements, fundamentally changing the realm of the possible for game development using Unity. Unity invited its developer community to let their imaginations run wild as to what could be achieved, showing off impressive demos. Unity also made it clear that it was still early stages, this would be a multi-year effort, and that it was looking to gather feedback from the community as it underwent development to guide the effort.

It’s now 2021, and Unity is making an announcement that the “future of Unity” won't be capable of running on current or future versions of Unity until further notice (which was explicitly stated as 2022 at the earliest). This a huge red flag about the current state and future of DOTS. It simply is not credible to say that DOTS is the future of Unity if it isn’t capable of running on future versions of Unity.

The closing statement just adds insult to injury:

Why can more not be shared at this time? Unity has just made an announcement that essentially calls into question the viability of what it had previously stated was the future of the platform. This is a middle finger to every member of the community that Unity asked to spend their time using the DOTS framework to provide them with feedback and help them develop the product. It’s like, “hey, we asked for your help and you’ve collectively invested tens (and probably hundreds) of thousands of hours of your time working with us to help improve our product which we've made all kinds of grand promises about, and now we’re announcing massive shifts in support for this product, and we’re hinting at the fact that there’s more going on behind the scenes, but we’re keeping that secret for now”. That is not how you treat a community that you value and respect, and that has invested immense amounts of time and effort into providing you with vast quantities of feedback at no cost to you.

Also, with all due respect to @MartinGram, a message of this significance should have been delivered by @Joachim_Ante. I realize he’s the CTO, but he frequently comments on the DOTS threads. At the very least, he should weigh in on this threat to provide more clarity on the suddenly very murky future of DOTS.

 

Interesting. So next version of Entities (e.g. 0.18) will run on 2021.3+ only?

I think UT changing something massive internally.
While it can sound dissapointing - its actually nice. A "stable / set" Entities version for everyone to run on with a LTS support.

 

No, the post states that 0.17, 0.18, and all future versions of Entities will need to use 2020 LTS until further notice. It is unclear what future version of Unity will support future versions of Entities. It could be 2021.3, or it could be 2022.1, or it could be some other release even further into the future.

We just know that the version won't be "until the end of the year at the earliest".

 

Well,

It has to run on something, right?
I mean, it could be that 0.18 will be in 2021 LTS. Or 2020 LTS.

To be honest, I'm pretty fine with this, as long as Entities are not actually abandoned.
Its a preview package in a transition state, so I've expected it to be as such.

At some point its expected for tech development to run into a plain wall when migrating a whole engine to a different architecture. And would require drastic changes that will break backward compatibility. I think this is what happens right now.

 

I agree that this could mean some great changes are coming. But what I cannot understand is Unity's silence. Without them telling us exactly what this is all about, we have to keep working for the next 8 months completely in the dark about what the future holds for DOTS. We have no idea if the work we're doing right now will be invalidated by massive API changes that might come out of all this.

Even that is not clear. The post says "you have to stay on Entities 0.17 for now". We have no idea if 0.18 will work on anything when it'll be released. And when I asked "Will future Entities packages still be released, even though they won't be compatible with any available Unity version?" earlier, the answer was simply "yes", without correcting my statement on 0.18 not being compatible with any engine version

 

The monkey-wrench thrown into this is that neither HDRP nor URP will be tied down and they are in sync with Unity versions. So if you need something new or some bug fix from either SRPs, too bad.

I understand that certain scenarios require to skip some engine versions because they are tearing apart something substantial under the hood, but the communication is abysmal as usual.

Although I don't share the doomsday-feeling some people exhibiting here either.

 

hmm possibly related? https://forum.unity.com/threads/unity-future-net-development-status.1092205/

 

Well, to quote Martin again:

So, he's pretty explicitly stating that the version that we have to work with for Entities is 2020 LTS.

I'm glad this works for you and your projects. This certainly won't cause a problem for some people. However, for others this is likely to generate huge headaches.

This has the effect of detaching ECS from the Tech Stream releases. If you're just using the Entities package alone, this might not be an issue. However, my guess is that many (if not most) people who are using the Entities package are also using the Hybrid Renderer package. After all, ECS is significantly less useful without it. This is a problem because the Hybrid Render has a dependency on Entities (which is now stuck in 2020 LTS until sometime in 2022 at least) while it also has a dependency on HDRP/URP which is moving ahead on the 2021 Tech Stream. Which means at some point these will diverge too much to be compatible, and you'll be stuck either with the 2020 LTS path in order to support ECS and lose out on the features added to HDRP/URP with the Hybrid Renderer or else you'll have to abandon ECS. This is made worse by the fact that URP still lacks many key features which are being implemented on the 2021 Tech Stream path. This is just a single example of why this is a problem.

Yes, an I expect issues working on a preview package as well. To me that means bugs, some features not being fully implemented, etc. That's all to be expected. What I don't think is reasonable to expect is that "the future of Unity" (that is DOTS and ECS) wouldn't be supported by future versions of Unity. That is a pretty absurd statement. And that's currently where we stand, until further notice, at least until the end of 2021.

 

Here is my South African style scenario planning exercise.

Scenario one: Some people in unity are not sold on ECS and it is being buried alive in order to not hurt other developers' investment both emotionally and physically.

Scenario two: ECS after some point 0.18? is going through a massive redesign and has an uncertain future.

Scenario three: ECS will continue its plodding evolution but something in 2021.1+ made supporting these versions too hard.

Scenario four: ECS will be released and developed as a separate game engine in the distant future.

 

Yeah, that's definitely unsettling. I'm making the assumption that since he did say "yes", that it means that yes Entities 0.18 would be released, and it I'm inferring from that that it must be compatible with 2020 LTS since you can't really "release" something if it doesn't run on anything. I mean, I guess technically you can, but I can't imagine anyone would actually do that.

I'm also assuming that the reason they're holding off on providing more information is that they're planning to provide a comprehensive update when Entities 0.18 is released, but frankly I think that ship has sailed. I think more answers are needed immediately, because the announcement in this thread calls into question the viability of any project (beyond a toy project) considering using ECS until at least 2022.

 

Yes, exactly. I think anyone saying "this seems fine" doesn't appreciate how much of a problem will be created by having HDRP/URP moving forward on a separate platform from Entities. That represents a huge, probably unacceptable, risk to anyone looking to use the Hybrid Renderer in a project that's for more than just playing around. And using Entities without the Hybrid Renderer is kind of like tying one hand behind your back. The fact that they can't even provide a more clear timeline that "not before the end of 2021" as to when that will be addressed just compounds the risk.

 

There is the possibility of having a specific editor version (like it was happening with DOTS-VS) which those new versions will be aimed at. We really need some clarification here.

 

My project only uses Entities and Physics staying on 2020 LTS would actually be fine we are actually still on 2020.1.17 right now. Unless you are close to releasing this may end up not being an issue but it is really hard to say where everything is going.

 

Probably not.

It's not that absurd if they need to change engine-features to go forward. They can't release them into the wild because that would kill the normal usage of the tech stream versions. I was kind of expecting something like this, but much earlier. But the communication is bad.

Pure nonsense.

This is what you signed up for when you started using a heavily preview feature. Nothing wrong with this. Unity didn't lie to you when they said ECS isn't production ready, use it on your own risk.

 

And yet you subscribe to Scenario three with a purity of passion which makes the angels tremble.

 

I'm not sure I understand what you're referring to. If you meant the same under your scenario three, than I will grant it an exception. Probably I just misunderstood what you wanted to say with that.

 

I'm going to have to disagree. "The future of Unity won't be supported by future versions of Unity" is most definitely an absurd statement. You make an excellent point as to why such an absurd statement might in fact be reality (reality can be absurd after all), but that doesn't make the statement itself any less absurd. That's what makes it such a poor communication.

I'm not trying to say I feel lied to by Unity, I don't. They didn't tell me this is a totally stable platform that was ready to use in a production environment on day one. However, they have spent a lot of time encouraging developers to use ECS, making statements about how it is core to the future of the platform, and so on. They didn't do this out of the goodness of their hearts, but rather, because they wanted to gather feedback on their framework and, probably more importantly, because they need a group of developers who know how to use this framework - which is a radical departure from their existing architecture - once they finally release it. What has me a bit annoyed is that they seem to have casually pulled the rug out on people on a Monday morning and left a cloud of confusion behind.

They have been actively encouraging people to use this technology for quite a while now, so that they had a ready developerbase when it was finally released, and now they're throwing what looks to be a major wrench in the works. It's a bit disingenuous if they come back and say "well, that's preview for you!" (which, to be fair, nobody from Unity has actually said that... because they haven't said much of anything yet).

 

I’m confused by this statement

“ With the way package management works from 2021.1, we have to have different ways of delivering Entities packages to our users.”

looking at the blog it just appears to be package name changes to experimental pre release and release. How on earth does this create a cross road for ECS.. also where does ECS land on this new classification, Pre release or experimental?

 

Also could it be that the ECS dev team want to work on a stable version of unity and not wast time on unrelated issues in tech streams that are slowing down ECS development?

 

It is experimental. Pre release is bound to be released until end of year.

 

What's frustrating is that I think the large majority of us would be totally ok (maybe even excited) with an announcement like this, if explanations were given regarding what is happening, why it's happening, and when to expect updates on the situation.

The only reason why people are angry is because of Unity's bizarre decision to not communicate at all and leave us in the dark. And I can't think of any good reason why Unity wouldn't want to explain. Feels like a lose-lose situation.

All of this could be solved right now, all it takes is someone from Unity coming here and writing a few short paragraphs

 

Yes, I completely agree with this. As much as I've expressed a lot of frustration in this thread (and I realize I have), I think this will probably all be fine. I think the schism created between the SRP and ECS development paths is going to be the source of a lot of pain for some people, but in the end it will probably be something people learn to work around as long as Unity is committed to trying to provide some help.

But the way this has been communicated has been terrible. Announcing what appears to be a seismic shift in support for ECS while providing little to no information about the implications and timeline and then going radio silent has made this infinitely more painful than it needed to be. And literally every minute that goes by without a more comprehensive response from the Unity team (or a least a statement saying, "we're sorry for the confusion this has caused, we're currently working on a comprehensive response, it will be coming <fill_in_the_timeframe>") is a missed opportunity for relationship management with the DOTS community.

 

How does this affect Tiny?

(Also, this is obviously an awful approach)

 

Wow that's really unfortunate, could you elaborate further why this change is needed? I am currently running DOTS, Physics, HR in 2021.2.0a10 without any issues. What changes in the Engine are so important that you have to lock out the whole ECS crowd from using the tech stream?

 

This is all likely the fallout of packages moving towards being in lockstep with Unity versions. They wouldn't want to announce that here as an official thing but in a separate post.

So if anything in 0.18 depends on something in alpha or even not in alpha yet, that would force everything else forward.

 

This is unfortunate, I believe that the reason of this is that all packages charge in rapid steps. This matter DOTS has to be updated to work with them and it may holding back development. And it may be just easier to develop DOTS in frozen environment.

 

After having some conversations and a night of sleep, I now think Unity told us everything we need to know. Unfortunately, the wording is so cryptic that you need to dissect it like some kind of ARG.

I don’t feel it is my place to decrypt it here, but I will re-iterate what this means for us right now. If you are using Entities and are not on Unity 2020.3 LTS, you need to switch to Unity 2020.3 LTS if you want a supported upgrade path to future Entities releases.

Personally, I think it is a really smart move (assuming my analysis is correct), but it is going to require better communication than this to gain the benefits of the new cadence.

 

If that's the case, it doesn't bode well for the future of DOTS development. The longer "release Unity" and ECS are allowed to diverge the more difficult it's going to be to reintegrate them into a common platform at a later date. They're saying "not before the end of 2021" for when these branches would be merged. That's a long time to accumulate incompatibilities that need to be resolved.