archived-dots

[rustic rain]

How to disable creation of default World?

[frosty siren]

AFAIK Project Settings -> Scripting Define Symbols -> Add line: UNITY_DISABLE_AUTOMATIC_SYSTEM_BOOTSTRAP

[errant hawk]

I created a new project with unity 2022.2b1 and almost all the entites packages have some sort of exception being thrown

I created a new project in 2022.2a17 and didnt have this issue at all

what changed?

[rustic rain]

2022 is not suitable version

@rotund token do you happen to know this error might be related to?
This is me trying to load external assembly with IJobEntityBatch system

    public partial class ModSystem : SystemBase
    {
        private EntityQuery _query;


        protected override void OnCreate()
        {
            _query = GetEntityQuery(ComponentType.ReadOnly<RotatingCube>(), ComponentType.ReadWrite<Rotation>());
        }

        protected override void OnUpdate()
        {
            Dependency = new RotateJob
            {
                rotHandle = GetComponentTypeHandle<Rotation>(),
                rcHandle = GetComponentTypeHandle<RotatingCube>(),
                delta = Time.DeltaTime
            }.ScheduleParallel(_query, Dependency);
        }

        private struct RotateJob : IJobEntityBatch
        {
            public ComponentTypeHandle<Rotation> rotHandle;
            [ReadOnly] public ComponentTypeHandle<RotatingCube> rcHandle;
            public float delta;

            public void Execute(ArchetypeChunk batchInChunk, int batchIndex)
            {
                var rotations = batchInChunk.GetNativeArray(rotHandle);
                var rcs = batchInChunk.GetNativeArray(rcHandle);
                for (int i = 0; i < rotations.Length; i++)
                {
                    var rc = rcs[i];
                    var rot = rotations[i];
                    rot.Value = math.mul(rot.Value, quaternion.RotateX(rc.speed * delta));
                    rotations[i] = rot;
                }
            }
        }
    }

[rustic rain]

I guess it's related to burst not being loaded

welp, judging by official burst docs

I literally have no other way

but enforce modders to use Editor to build mods

kek

[viral sonnet]

what were you plans then when it wasn't the editor?

[rustic rain]

my own XML parser

aaaand JIT compilation, kek

[rotund token]

Oh I've seen this

did you tell burst to load the new dll

(sounds like you might have realised this)

[rustic rain]

currently I am having trouble to even build mod dll

importing Assembly-CSharp

causes errors

not sure if that's the case though

Soooo, Burst manual has this script for building mod

    public static void BuildGame()
    {
        string modName = "TestMod";

        string projectFolder = Path.Combine(Application.dataPath, "..");
        string buildFolder = Path.Combine(projectFolder, "PluginTemp");

        // Get filename.
        string path = EditorUtility.SaveFolderPanel("Choose Final Mod Location", "", "");

        FileUtil.DeleteFileOrDirectory(buildFolder);
        Directory.CreateDirectory(buildFolder);

        // Build player.
        var report = BuildPipeline.BuildPlayer(new[] { "Assets/Scenes/SampleScene.unity" }, Path.Combine(buildFolder, $"{modName}.exe"), BuildTarget.StandaloneWindows64, BuildOptions.Development);

        if (report.summary.result == UnityEditor.Build.Reporting.BuildResult.Succeeded)
        {
            // Copy Managed library
            var managedDest = Path.Combine(path, $"{modName}_Managed.dll");
            var managedSrc = Path.Combine(buildFolder, $"{modName}_Data/Managed/{modName}_Managed.dll");
            FileUtil.DeleteFileOrDirectory(managedDest);
            if (!File.Exists(managedDest))  // Managed side not unloaded
                FileUtil.CopyFileOrDirectory(managedSrc, managedDest);
            else
                Debug.LogWarning($"Couldn't update manged dll, {managedDest} is it currently in use?");

            // Copy Burst library
            var burstedDest = Path.Combine(path, $"{modName}_win_x86_64.dll");
            var burstedSrc = Path.Combine(buildFolder, $"{modName}_Data/Plugins/x86_64/lib_burst_generated.dll");
            FileUtil.DeleteFileOrDirectory(burstedDest);
            if (!File.Exists(burstedDest))
                FileUtil.CopyFileOrDirectory(burstedSrc, burstedDest);
            else
                Debug.LogWarning($"Couldn't update bursted dll, {burstedDest} is it currently in use?");
        }
    }

but I'm confused

_Managed.dll

where is it even supposed to be

[rustic rain]

huh

It works

For some reason Manual has some very weird path errors xD

but mod works

loaded assembly

which even loaded all systems normally

one system*

so, now I need to test Harmony patching

of bursted code

[rustic rain]

welp

sadly doesn't work

[rustic rain]

hold oooon

looks like it works

kek

[rotund token]

Well this is a roller-coaster

[rustic rain]

hehehe

and patch indeed works

also what is most fun - I can test it as modder right from editor

[rotund token]

Confirmed its executing as burst?

[rustic rain]

hmmm

I do have tick "Burst compilation"

not sure how to actually check

[rotund token]

Just hook up a profiler

[rustic rain]

whether it's bursted

[rotund token]

Or add a conditional pass with burst discard that debugs something different in burst or mono

[rustic rain]

oh well, looks like burst gets discarded

[rotund token]

Did you pass the dll to the burst method that it requires

[rustic rain]

    [HarmonyPatch("RotateCubeSystem_LambdaJob_0_Job", "OriginalLambdaBody")]
    public static class PatchRotatingSystem
    {
        public static void Postfix(float ___delta, ref Rotation rot, in RotatingCube rc)
        {
            rot.Value = math.mul(rot.Value, quaternion.RotateZ(-rc.speed * ___delta));
        }
    }

[rustic rain]

yeah, I load both

but

oh wait

maybe I should apply [BurstCompile] to patch

nah, didn't help

[rotund token]

I'm not sure why that would patch the burst job instead of the mono

i'm not super familiar with harmony but from what i understand it patches .net methods at runtime

but you need to precompile burst

[rustic rain]

    [HarmonyPatch("RotateCubeSystem_LambdaJob_0_Job", "OriginalLambdaBody")]
    [BurstCompile]
    public static class PatchRotatingSystem
    {
        [BurstCompile]
        public static void Postfix(float ___delta, ref Rotation rot, in RotatingCube rc)
        {
            rot.Value = math.mul(rot.Value, quaternion.RotateZ(-rc.speed * ___delta));
        }
    }

I tried this

I assume it compiles that method for jobs, right?

[rotund token]

you can't pass structs into function pointers in burst

hmm

harmony does not support patching native methods

so i just don't see how this would ever work?

[rustic rain]

fully recompile job?

is it possible in runtime?

[rotund token]

no

[rustic rain]

aren't generic jobs work like this?

[rotund token]

you have to register all generic jobs in advanced

this is the whole restriction behind generics and burst

[rustic rain]

ah

https://harmony.pardeike.net/articles/patching-edgecases.html

hmmm

[rotund token]

not sure how much that helps you though

[rustic rain]

I guess

Unity just needs to add support for recompilation

[rotund token]

i always imagined modding with entities/burst to simply be writing your own new burst jobs, using write groups to override existing behaviour and loading them with BurstRuntime.LoadAdditionalLibrary(burstedAssembly)

[rustic rain]

certainly it's an option, but mostly ppl just want to modify some existing behaviour

so that everyone else who relies on this behaviour

can keep on relying on it

[rotund token]

i don't see why overriding existing behaviour with write groups would be any different for other users

[rustic rain]

ECS kind of makes it better though

since it's all just data

so it makes no different what modified it

[rustic rain]

sometimes write groups don't exist

there's Just no tag on job, since I'd never even think someone would want to override it

but here we go

[rotund token]

that seems to be up to the developer, i.e. you, to decide 😄

[rustic rain]

well yeah, but in normal mono Harmony brutforced it

so you could patch literally anything

[rotund token]

This city deserves a better class of modder

anyway this is all just a vision from me, i don't think of it as modding more collaborative development

[rustic rain]

that's until someone tries to implement anime cat girls with superpowers into your game

[rotund token]

I'm a man of the people

If that's what the people want, that's what the people get

[rustic rain]

that's why Unity needs to make runtime recompilation possible

maybe just make some static method to manually call it

[rotund token]

i can't see burst being used outside the editor anytime soon

or ever

big difference between aot and jit code

[rustic rain]

oooooh

hold on

I have to check one thing first

nnnah

that didn't work

[rotund token]

recompile your game with il2cpp and then use harmony

does that work?

[rustic rain]

I never used il2cpp tbh

I'd need a little bit of research before I can test

and that would be delayed till tomorrow

[rotund token]

it was kind of a rhetorical question

as far as i'm aware you need something like BepInEx

[balmy thistle]

Does Harmony work with il2cpp? It sounds like it needs access to the IL

[rotund token]

it doesn't as far as i'm aware, it's an IL patcher

[balmy thistle]

Yeah I'd be surprised

[devout prairie]

so i'm just thinking out loud here..

is there much of a difference between say passing in ComponentDataFromEntity<LocalToWorld>, as an example

compared to first firing a job that iterates the LTW's and fills an array with the values, and passing that in

[harsh quiver]

It's pretty fast 😉 The query part of this article has more info on how it is implemented. TL;DR most relationship queries are just as cheap as regular ECS queries https://ajmmertens.medium.com/building-games-in-ecs-with-entity-relationships-657275ba2c6c

For simple wildcard queries all the ECS has to do is "find all tables with (Effect, *)" which is an O(1) operation, and then it can just iterate the list

[rustic rain]

I don't get it though

Does it mean you need to know relationship during compile time

Or are queries can be generalized somehow?

[harsh quiver]

Nope! Everything (including component registration, query creation) is done at runtime

When a component (or relationship) is first added to an entity, an index is created for it that stores all tables for that component

[rustic rain]

But how so you query through relationship?

Do you just create a loop of

Uugh

For example

Likes With Entity as value argument?

[harsh quiver]

Ah no, that would be slow. What happens is internally I translate a relationship pair (for example, (Likes, Cars)) to a component id

I can then add that component id (which is actually a relationship pair) to an entity

This blog has more info on how the pair is packed into a component id https://ajmmertens.medium.com/doing-a-lot-with-a-little-ecs-identifiers-25a72bd2647, the TL;DR is that I use a single 64bit int to encode two 32bit ids

[rustic rain]

So all it actually is just double tag generic component?

Basically uugh

Relationship<T0,T1>

[harsh quiver]

Yep that's right 🙂 The ECS storage doesn't really need to know about relationships, it just works with ids. You could emulate that part with generics (or templates in C++)

[rustic rain]

I can definitely see the benefits of using it

Wonder though whether this can already be implemented

In unity ECS

[harsh quiver]

Things get a bit, but not much, more complex with queries. I want to be able to query for (Likes, *), even though I never add (Likes, *) to an entity. Another thing outside of the storage that is a bit harder is cleanup: if you delete a parent entity, you want to delete all entities with a (ChildOf, parent) relationship

[rustic rain]

I remember seeing smth about generic component

Gotta read about it

But you said it's tag

Meanwhile Parent is actually value

Unless it's some hardcoded singleton

[harsh quiver]

Right, so, both ids that are encoded in a pair are actually entity ids

Components, relationships, parents, normal entities, all have entity ids

Entity ids are always runtime, which is why I can add (ChildOf, parent) to an entity

[rustic rain]

Well this one sounds like a trouble already

Although

Maybe it can look like

[harsh quiver]

It lets you do lots of cool stuff. Like, what if you could add a Serializable tag to your component, so you could query all entities with serializable components

[rustic rain]

Relationship<Likes, Entity> after all

Meaning it would be not just pair

But a tag + struct

So total size of such component is 8 bytes

I even feel like if generic components is a thing it actually might work, kek

[harsh quiver]

Yeah, but the nice thing about keeping it entity ids is that you don't need to know about anything at compile time 🙂

[rustic rain]

Oh well

Seems like this one is fully supported

[harsh quiver]

Relationships can also contain data:

e.set<Position, Begin>({0, 0});
e.set<Position, End>({10, 20});

[rustic rain]

But

It kind of inlines it all to basic struct

So in the end

You can't add multiple of( likes, entity) pair

[harsh quiver]

I can 😉

[rustic rain]

I mean in Unity ECS

[harsh quiver]

Ahh right. Yeah before relationships I had the same problem

[rustic rain]

Well, currently

This all can be solved through dynamic buffer component

Just call it

Likes

[harsh quiver]

That's true, but you'd be missing out on indexing

[rustic rain]

As a wrapper of entity

[harsh quiver]

Say I want to find all entities with (Eats, Apples). I'd have to iterate all entities with (Eats, *)

[rustic rain]

I honestly just don't see how indexing of actual entity would work in unity

Since from what I understand

Types are resolved only once

Not dynamically

And if you actually remember type as id

So entity is removed

And now type id is corrupt

[harsh quiver]

Yep, that's where cleanup comes in. When an entity is deleted, I delete all references to that entity

[rustic rain]

Or...

Since unity ecs using pair of ints

Index and Version

Maybe this will just keep creating new ids

But I don't see how quering it would be fast

Since you'd need to get new query every time

As each new component id creates new archetype

Smth for Unity to crack I guess

[harsh quiver]

Hah yes 😋 You're exactly listing the problems one by one that need to be solved

They can be solved though

[rustic rain]

Tbh

[harsh quiver]

This is a fun one, since this means that if you delete a parent entity, you need to delete archetypes with children for that parent

[rustic rain]

There is already similar filtering

With shared components

You can filter by value

But shared components are always considered managed

And they create way too many double archetypes for their implementation

[harsh quiver]

yes, you can do similar things with that

in my implementation shared components are implemented through relationships, they kind of sit at the same (archetype) level

[rustic rain]

But that makes filtering way slower

It'll have to check per entity

Meanwhile current implementation checks by chunk

[harsh quiver]

btw, if you want to play around with this stuff, try https://bit.ly/3oqPCD0

[harsh quiver]

relationships are checked per archetype/table

they're similar to components, like:

entity Likes = world.entity();
entity Bob = world.entity();
entity Alice = world.entity();

Bob.set<Position>({10, 20}); // bob is in archetype [Position]
Bob.add(Likes, Alice);       // bob is in archetype [Position, (Likes, Alice)]

[rustic rain]

Yeah, I get that part

Value is transformed into type id

Exactly how shared components work

And actually

They say they work on unmanaged version of shared component

So maybe it would it

[rustic rain]

All right, my fun with Harmony patching continues

turns out last time I checked I forgot to import bursted library

kek

into mod project

[rustic rain]

Welp

turns out

you still can't patch bursted methods

you end up with only unbursted part being patched

so... it works when you disable burst

but not when it's on

that is a very sad constraint

[viral sonnet]

@harsh quiver How are the relationships modeled in memory then? This all sounds nice to me but I'm also expecting a lot of iterations on fragmented memory with lots of random access.

[harsh quiver]

Yeah good question. On the storage/archetype level relationships don't really exist. It just knows of ids that can be associated with a datatype (components) or not (tags). A relationship pair like (Likes, Alice) is packed into a regular component id which is treated by the storage like any other component/tag

So in theory relationships are just as fast/slow as working with regular components.

The caveat is that relationship pairs can contain regular entities, of which there can be a lot. An application that's a heavy user of relationships will see increased archetype fragmentation

There are a couple of ways to deal with that, some framework side some application side:

• make your archetype creation fast and overhead low (some flecs apps run with 50-500k archetypes)
• use features that reduce fragmentation, like component enabling/disabling (bitset based, I believe dots has a similar feature)
• use non-fragmenting relationships (a special kind of relationship that does not fragment but is slower to iterate)

A big storage upgrade I've been working on separates tables from archetypes, where a table only stores components, archetypes store the id lists for components & tags, and multiple archetypes can index into the same table.

You still get archetype fragmentation, but tables (where it matters most, since they store the data) don't get fragmented by tags

That way you can have your cake and eat it too: pure component queries can iterate big unfragmented chunks of memory, while query for tags/relationship pairs eat a slight indexing overhead

(sorry for the wall of text, it's a simple question with a complex answer :p)

[viral sonnet]

don't be sorry, i appreciate it 🙂

the most basic problem I have in ECS is a target relationship. entity can have another entity as target. both entities have a position, get the distance of these targets. highly random memory access job to calculate that data.

worst of all, no simd

[rustic rain]

can always split into several stages: grab data, iterate over grabbed data, write data

all will be lined up good for cache

[harsh quiver]

Right, so this is a common use case: have a Transform system (or similar) use a Position component from the entity itself as well as from its parent. Here the fragmenting relationship behavior is actually desirable, since all children for a parent pare packed in the same table. This means you can reuse the same parent's Position component for the entire table, which means you can do SIMD again

It's not perfect, you can have a degenerate case with lots of parents and tiny child tables

But even if you only have a handful of entities in a table, it'll perform slightly better than 100% random access

Something else you can leverage here is that because you're likely iterating cached query results (I'm assuming dots does this), you can sort cached tables breadth-first based on the scene graph, which ensures parent Position components are processed before children. The sorting of tables is almost free

[viral sonnet]

hm, i fail to see the similarity between parent/child. a target can change and the target position can change. otherwise it would be possible to cache or duplicate the data for better access patterns

[viral sonnet]

that won't make anything faster 🙂 you just split the work load

[harsh quiver]

Oh true, but what I meant is the cache of a query, which maintains a list of matched tables

[viral sonnet]

yeah entities doesn't have that 😄 afaik it doesn't even have caching in that sense

[harsh quiver]

Say you have a table with ids [Position, (ChildOf, some_parent)]. If you want to transform all entities in that table, you only need to fetch the parent's Position once

Oh really? That'd surprise me

Cached queries make a lot of sense for an archetype based ECS, even more so if you don't have relationships which means the list of archetypes is very stable

[viral sonnet]

some time ago i tested effect entities and to my surprise having lots of entities slowed down the whole system. tertle then told me entities has to evaluate every archetype and chunk for the queries. so pretty sure, no caching, otherwise this wouldn't happen i think

so just creating like 10mil entities in 1 archetype slowed down every system. even though no system worked on the 10 mil entities

[harsh quiver]

that's weird, trying to think of anything that could cause that

[viral sonnet]

yep, i was pretty perplexed too. didn't think this would happen

[harsh quiver]

even if queries aren't cached, a system query doesn't have to look at individual entities, it just needs to match archetypes

[viral sonnet]

maybe it's memory fragmentation. like relevant chunk A/B/C, lots of D chunks that don't do anything and then relevant chunks E/F/G

afaik it also checks chunks (for whatever reason)

[harsh quiver]

maybe the job system gets flooded with a job per chunk

idk, don't know dots that well

in any case, that doesn't happen in my code, so the relationship stuff doesn't suffer from it :p

in a small set of use cases relationships can improve cache efficiency as it lets you build instancing-like behavior on the CPU

e.g. loading a single shared component inherited from a prefab puts a lot less pressure on the CPU cache than having to load a private copy for each iterated entity

I heavily rely on that in this project https://flecs.dev/city where most of the component data is shared across prefabs

(not as impressive as the unity megacity demo :p but you gotta start somewhere as a solo dev)

[rustic rain]

hmmm

what I figured

in case you need some entity-entity relationship with random access

[viral sonnet]

pretty cool stuff. what code language is most of this city demo? flecs itself is c++ and i see all this browser stuff 🙂

[rustic rain]

ah, nvm

[viral sonnet]

btw. can i access this dashboard for the city demo?

[harsh quiver]

That project is almost all C with a bit of JS glue code. Flecs is a C core with a C++ binding

[harsh quiver]

You can, but for now you need to run it on your local machine

if you run the city demo as a desktop app and go to https://www.flecs.dev/explorer/, it should connect to the demo

at some point I'll figure out how to run both in the same browser tab, but not there yet

[viral sonnet]

how do you fragment your tables? same as entities with 16k chunks?

[harsh quiver]

Nope, I don't chunk my tables

It wouldn't scale for me, I need to be able to support hundreds of thousands of tables. If each table is at least the size of one chunk, that'd blow up in memory very quickly

[viral sonnet]

oh so how do you handle adding/removing to those tables?

[harsh quiver]

Each component vector is a separate array. When I move an entity out of a table, I iterate each vector, and move the last element into the entity's old spot

Table insertion is a simple append to each vector

this is fast path for it, not a lot of stuff going on: https://github.com/SanderMertens/flecs/blob/master/src/table.c#L1699

[viral sonnet]

so having a million entities would involve a memcpy when the vector capacity exceeds?

[harsh quiver]

Yep, that's the tradeoff

I've been working on a pluggable storage prototype where you could do something custom for extreme cases like these (even use chunks if you wanted to)

but that's still a few months out

it could make sense to use chunked storages for large tables, and regular storages for small ones

[viral sonnet]

i see, yeah when its modular enough i dont see much downsides. for low entity amounts its even preferred

the lack of modularity sucks in entities.

[harsh quiver]

having a single table with 1m entities is rare though :p I'm already happy if I see a table with a few thousand entities

[harsh quiver]

to be fair, modularity without giving up perf is hard

[viral sonnet]

haha, tertle and me do that all the time. he's now up to 100mil test cases

[harsh quiver]

oh yeah, it's not hard to create a table with 1 million entities, but I haven't seen it yet in actual applications heh

[viral sonnet]

(not that these are realistic in game scenarios) we just have fun with it

[harsh quiver]

as soon as I start writing ECS code I stop caring about fragmentation and I'm adding/removing components left and right 🙃

[viral sonnet]

with your approach adding/removing comps doesn't change archetypes right? afaik they are decoupled in flecs

[harsh quiver]

in the new table vs. archetype design adding/removing comps would change archetype, but not table

I'm still working on it though, so by default adding/removing does change tables

[viral sonnet]

because one of the big issues in entities is removing a comp needs a memcpy of all entity data in that archetype

which is a big performance problem

[harsh quiver]

Hm really? it's not like I haven't seen this be an issue, but it doesn't come up a lot. It can become a problem for big components, or components that are complex to move

Though yeah if you're generating add/remove's for 1m entities each frame that would definitely bring everything down to a crawl

[viral sonnet]

wouldn't even need that much. adding something like an event comp on 250k is already a huge spike

[harsh quiver]

Part of the new storage design I'm working on is to allow for storages that can be indexed by "table index" (the row of the entity in the table) and entity id. The latter would make it possible to have a single storage per world per type, which you wouldn't have to move when an entity changes archetype

[harsh quiver]

yeah true. does dots support bulk add/remove operations?

that's the only way I could make that work performantly in flecs I think

[viral sonnet]

it does. remove is quite fast obviously. adding can also have the, too much data in a single frame problem

allocating so much data is just a general problem

[harsh quiver]

in the best case you add a component to all entities in a table (or matching a query), and the target tables are empty

in that case you can just move the comp arrays (or chunks in the case of dots)

something I've also been toying with is the idea to keep track of destination archetype while enqueueing commands

that way if you have 10 commands enqueued for the same entity, you'd first move it to the right archetype, then apply the commands

vs. having to do 10 archetype moves

[viral sonnet]

sounds like a good way to handle it

[harsh quiver]

lots of ideas, very little time :p

[devout prairie]

has FLECS been tried with unity, sounds really interesting

[harsh quiver]

it has, in all sorts of creative ways heh

there's a C# binding in development, though I don't think it's quite ready yet

somebody also just posted a project today that reads in a Unity scene file and converts it to a flecs scene prefabs and all, which was .. surprising

[devout prairie]

haha nice

do you have a render engine for it?

i'm guessing a no for that 😛

[harsh quiver]

Surprisingly yes #729773810953355355 message but don't quote me on how usable it is, I think it's still very early days. I believe it is using the Forge

[devout prairie]

interesting to hear a different approach to ecs though.. i remember reading the DOD book that unity shared way back, some guy discussing in detail the benefits of DOD and ECS, and how it can be thought of in terms of a database access kindof mechanic.. was really eye opening actually and laid out the case for DOD/ECS really well

[devout prairie]

ah i don't have access, is this your own discord server?

dm me an invite if it is 🙂

[harsh quiver]

I did build a toy renderer which is used by this https://flecs.dev/city and a few other demo projects, but my render coding skills are nothing short of unimpressive :p I'm hoping someone more qualified will some day pick up the renderer and turn it into something decent heh

DM'd

[devout prairie]

hah, that is really nice

[harsh quiver]

I spent three weeks trying to get the ssao to work and it's still glitchy as hell

[devout prairie]

that was the first thing i noticed, it has AO!

and bloom

[harsh quiver]

bloom is not that hard, just blur & combine

the ssao is let's say "finely tuned" for this scene :p don't try it for anything else

[devout prairie]

how about physics? that natural progression i guess is a full pipeline with maybe a c++ api or something right

even just bolting together some existing solutions i guess, if they're fast and modular etc

[harsh quiver]

Yeah, I've made some attempts at that but they're kind of at the same level of the renderer heh. I'm trying to develop a bunch of modules (these ones https://github.com/SanderMertens/flecs#flecs-hub) that when combined can be used as an engine

That's still waay far off though, I'm happy if it'll ever be sufficient for a gamejam

The physics module has some basic features, like it can populate an octree from ECS data

No rigidbody physics or anything close to it

[devout prairie]

really cool stuff 🙂

[harsh quiver]

it's okay, I'm having fun with it ^^ more than anything I'm trying things out that I'd like to see in a game engine but not sure if they're possible

like single-line imports of ECS modules. It should be possible to make a 3D app headless by un-importing the renderer module

lot of interesting problems around how you order systems imported from different modules (I've seen some dots features like system groups for this, pretty cool)

another moonshot idea I'm trying out is if I can build a renderer that uses ECS queries to batch entities for different render pipelines

like, the render pass for solid objects matches entities with Rgb, the render pass for transparent objects matches entities with Rgba

[devout prairie]

ahh interesting

i was just looking at the Forge, i hadn't seen that before, so it's using Flecs as it's built in ECS implementation

[harsh quiver]

yup yup ^^ not sure how many people actually use it though :p the Forge is more of a toolkit where you use what you want

still cool they took the effort to integrate it

[devout prairie]

yeah definitely, it's great to see independent toolsets being developed that in fact are competitive with top level products

Blender probably being the greatest of all examples of that in many ways

[harsh quiver]

blender is awesome (though I'm Dutch so definitely biased)

[devout prairie]

hehe, ton roosondal is like the prophet i think

[harsh quiver]

haha he is :p

Those new geometry nodes look awesome.. I wish I could do something like that in ECS. Like a node-based approach to generating an ECS scene graph

[devout prairie]

regards dod/ecs, i genuinely think it's going to be a game changer over the next ten years, largely due to how much more efficient it is, compared to how wasteful the 'traditional' oop approach so often is, in terms of energy/resource utilization etc.. we're moving into a world of carbon credits and energy i think is going to be increasingly precious.. if you have a platform that users can use that is reliable and can produce applications that cater to that level of efficiency etc, i think you'll be ready for the new world

[rustic rain]

ten years?

it's already a game changer

[devout prairie]

ok two weeks

[rustic rain]

utilizing all cores

who else does it, kek

[devout prairie]

absolutely, it is

but i believe it's basically going to be a requirement, pretty soon

the old world of oop will soon be gone 😛

i think maybe a world with the best of both.. the benefits of an oop layer over an ecs foundation

[harsh quiver]

Agreed. What's funny is I use ECS in my day job but not for a game. I use it to construct a huge graph in realtime from real-life objects that once they're loaded you can do all sorts of fun stuff with. I have no idea how I would've done anything close to it without ECS, and not even just because of perf

Just not having to deal with fixed type hierarches that put in stone what an object can and can't have is liberating

[devout prairie]

yeahp, and ridiculous layers of inheritance etc

just data and transforms

[harsh quiver]

usability is still a bit of a problem though

ECS libraries need to get their * together when it comes to behavior that only matches single entities

I'm also hearing from a lot of folks that not having native language support for it can be a barrier

[devout prairie]

how do you mean?

[rustic rain]

singleton

[devout prairie]

ah right yeh

[harsh quiver]

Like what if you have a system that only matches a specific boss in your game. It's totally possible with todays libraries, but gosh I have to write a system with an interface that's clearly optimized for iterating multiple entities, need to make sure I'm matching all the right components, probably need to introduce a tag specific to that boss so I don't accidentally match the wrong thing

Vs. here's a class with an update() method, go

There's sometimes this sense that if you use inheritance or have a system that's coupled to an entity the ECS code isn't pure enough

which leads to people pretending that a MeleeUnit isn't a subclass of Unit (it is) or that the DragonAttackBehavior system isn't tightly coupled with the dragon boss at level 2 (it is)

[devout prairie]

right yeh that makes sense

[harsh quiver]

(also, I only know a handful of ECS libraries, so maybe dots has better solutions for this that I'm not aware of)

[viral sonnet]

it's time for cpu creators to utilize the logic of ecs on a hardware level 😄

[devout prairie]

i have to say i have a liiiitle bit of trepidation when i think about what unity is doing and look back to the end times of flash..

i think unity are still kindof keeping one foot in the old world and one foot in the new, which was kinda what killed flash really

[viral sonnet]

deprecation of the npapi killed flash

[devout prairie]

actionscript started leveraging more low level access, there were even tools to write super fast native c code and leverage it etc

but ultimately, the html5 revolution just left it behind

[rustic rain]

Do you guys know whether it's possible to build separate Burst library for each built assembly in project?

[devout prairie]

interesting that just the battery life consideration was a big factor, and that was then.. even more important now

[rustic rain]

basically so that Player's burst lib and actual project's burst lib are separate

[rotund token]

I'm not sure if you can split it per assembly, though the editor actually splits every job into its own dll

But you can load more than 1 burst dll at runtime

[rustic rain]

it's only required for mod project

[rustic rain]

I tried to load original project's burst plugin

but it resulted in tons of exceptions

lemme boot it and show

        [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.AfterAssembliesLoaded)]
        public static void Load()
        {
            var path = Path.Combine(Application.dataPath, "Reference/UnityECSModTestBurst.dll");
            Debug.Log(path);
            if (File.Exists(path))
            {
                BurstRuntime.LoadAdditionalLibrary(path);
                Debug.Log("Loaded reference burst");
            }
            else
            {
                Debug.LogError("Didn't load reference burst, file doesn't exist");
            }
        }

here how I load it

and here what I get 👴

xD

here first errors

what I assume: original project's build compiled it all into 1 library

and now it is having trouble Editor's player burst libraries

[errant hawk]

which unity editor version works with entities 0.51-preview32? I can't seem to add the entities package anymore without errors

[solar spire]

https://docs.unity3d.com/Packages/com.unity.entities@0.51/manual/install_setup.html#unity-editor-version

[errant hawk]

I don't use anything prior to unity 2021.3.6f1

I cant seem to import the package without entities forcing v1.7.2 of burst, when the docs claim it will install 1.6.4 (which I installed ahead of time)

[solar spire]

What version are you using then?

[errant hawk]

as that seems to be the majority of conflics

at this time, using 2022.2.a17

I tried the beta, but it was worse

[solar spire]

You have to either be on a 2020.3 or 2021.3 version

(above the mentioned ones)

[errant hawk]

I also tried 2021.3, 2022.1.8, and 2022.2b1 with similar issues regarding packages. Neither seems to allow for the correct package anymore

[rustic rain]

2021.3.4+ works

I use this

but it has some weird bug with android builder

[errant hawk]

I cant import without the console screaming at me saying there's 50+ ambiguous references... importing the correct package has not even allowed me to change the version number because entities requires a newer package than the one described on their docs

I also have tried 2021.3.6f1 with the same results

last week I created a project and imported everything entities related without issue in 2022.2.a17.... but now I cant

[rustic rain]

so

can you just try create new project?

[errant hawk]

this is a new project

brand new

[rustic rain]

and how exactly

[errant hawk]

first thing added is entites

[rustic rain]

are you installing DOTS packages

[errant hawk]

com.unity.entites

[rustic rain]

through package manager or manifest?

[errant hawk]

package manager

[rustic rain]

try manifest

    "com.unity.burst": "1.7.3",
    "com.unity.rendering.hybrid" : "0.51.0-preview.32",

you can add these 2 lines

and you'll get all dependencies resolved

for you

this will give you all required ECS + Jobs + Burst packages

without Physics though

[errant hawk]

what version of collections and mathematics are you using?

[rustic rain]

idk

they are resolved for me

and I haven't had any need in other version

[errant hawk]

Still having issues

[rustic rain]

can you show your manifest?

[errant hawk]

Some of the version numbers are not even correct because the package manager shows a different version

[rustic rain]

why are you defining packages manually?

you probably have some of them wrong

remove all dots related packages

but those 2 sent

[errant hawk]

im just going to create a new project and send that manifest

[rustic rain]

sir

just create new project

and add to manifest those 2 lines I sent you

this will give you all you need for Dots

when you create project

pick URP/HDRP template

[solar spire]

I imagine the problem is using that version of Collections

[errant hawk]

I had the correct versions described on the DOTS docs page, but adding entities package auto resolves to a newer version

I tried manually setting the version afterwards using the package manager with no success

@rustic rain here's the manifest I got when creating a new project in 2021.3.6f1 (the one you use)

[rustic rain]

now just add those 2 lines to the top

don't even touch package manager

[errant hawk]

ok that worked

how

something must be messed up with the package manager

it's weird, because all the packages relating to burst/mathematics/collections/entities is the same version on the other projects that have issues

[rustic rain]

all these packages are preview

package manager doesn't work with them

[errant hawk]

well that's wack

[rustic rain]

it is

no idea why they made it the way it is

older version worked fine with preview packages

[rustic rain]

hmm

Is there a way to figure out whether burst is working in build?

[errant hawk]

Debug.Log works inside Burstified jobs

[rustic rain]

ah yes, Burst Discard

welp

looks like JIT burst

doesn't work

That is sad

[errant hawk]

AOT is what burst uses in builds, and JIT in editor afaik

[rustic rain]

yeah, but if you import dll of build into editor

JIT won't work either

and that is a problem for modding

I am trying to solve

[errant hawk]

huh yeah that is an issue

Try the Synchronous Compilation setting under the Jobs tab. No idea if that will change anything for builds tho

Also, instead of using compiled mods, you could try hot-loading source code instead

[rustic rain]

oof

I wouldn't want to make game open source this way

besides

sharing source code this way would be even more pain

[errant hawk]

you would not need to opensource you game. Just an API wrapper that interfaces with the mods and your game

[rustic rain]

ahem, hot loading source code is not supported at all

for burst

kek

besides

that's not the problem

final game that loads mod does work with burst (I think)

the problem is related to smth else

it's mod project

once you loaded assembly of game build

nothing of burst works in editor for mod project

meaning big scaled projects will be impossible to run in editor

for modders

[errant hawk]

@rustic rain https://docs.unity3d.com/Packages/com.unity.burst@1.6/manual/docs/ModdingSupport.html

[rustic rain]

yeah, that's what I used in the first place

allthough it has errors, kek

[errant hawk]

what kind of errors?

[rustic rain]

naming pattern is wrong

there is no _Managed suffix

on built dll

[errant hawk]

the names assigned when using the PluginManager script are arbitrary

https://docs.unity3d.com/Packages/com.unity.burst@1.6/manual/docs/ModdingSupport.html#simple-create-mod-menu-button

[rustic rain]

assembly names aren't

[errant hawk]

compiled mods should fall under an entirely unique assembly that is unique to that mod

[rustic rain]

yeah, and for some reason they thought that it would have _Managed suffix

[errant hawk]

From the looks of it, Unity is loading an Assembly as expected, and then loading it using Activator

[rustic rain]

nothing wrong with that

it's editor part

not build

[errant hawk]

Then change how the editor script reads names to the compiled .dlls

[rustic rain]

sir, I did it long time ago
Once again, it's Modder's experience that is my concern

because as modder you can't get bursted game assembly

thus if you try to test some mechanic that relies on existing one which potentially is heavy

you'll end up testing in 0.1fps conditions

Just checked

mod assembly loaded by game works fine

burst loads correctly

[rustic rain]

hmmm

here's crash stacktrace

[rustic rain]

also nvm, burst does not load correctly

hmmm

how would you structure prefab database?

the way so you can easily query over them by string, change them however you want and etc

also very important - the way so you can collect them

[viral sonnet]

a hashmap? 🙂

[rustic rain]

well yeah, that's obvious

but I'm confused over how to manage it

I need to keep link to prefab in instantiated entities

so they can be later saved and restored by that prefab reference

I'm considering shared component

so memory overhead is 0

[rotund token]

i use weak references

similar system that the dots shooter used to manage it's prefabs

[rustic rain]

could you elaborate?

[rotund token]

https://github.com/Unity-Technologies/DOTSSample/blob/master/Assets/Unity.Sample.Core/Scripts/WeakAssetReference/WeakAssetReference.cs

this is just to link the actual presentation if required
i don't save this though as this exists on the prefab, prefabs (and objects in subscenes) in my save system are auto generated unique IDs using https://docs.unity3d.com/ScriptReference/GlobalObjectId.html

[rustic rain]

I can't and probably should not rely on IDs

what I would like to use is string (fixed)

because that's the best way to keep unique reference between game, modders and etc

at least I think so

[rotund token]

not sure how having you users choose strings, "monster", is going to be more unique than guids

[rustic rain]

Because they will probably want to instantiate some prefab

in code

[rotund token]

so? make them call your method to get an id

[rustic rain]

and pass what in for it?

[rotund token]

nothing

[rustic rain]

how would I know then what prefab to give to them

my point is:
modder creates some prefabs that get instantiated into world as prefabs and then saved in database

Then in some trigger event or smth he wants that prefab to be instantiated and do smth with it
what would be a way to get that reference?

[rotund token]

from the guid he was given

[rustic rain]

and what does he pass as argument to get that guid

prefab is instantiated outside of his control

[rotund token]

var id = GetUniqueID();
DataBase.RegisterPrefab(id, myprefab);

user does what the fuck they like

[rustic rain]

it's just written into world

that's the point

there is no prefab for user

he is not the one writing to database

[rotund token]

so the prefabs already exist?

[rustic rain]

yes

[rotund token]

then i dont see the problem at all

i thought the problem was you wanted modders to be able to add prefabs

[rustic rain]

but how would you get a reference to that prefab?

if it's written behind IDs

[rotund token]

var prefab = DataBase.GetPrefab(id);

[rustic rain]

there is no way to know beforehand

what id is it

[rotund token]

whatever id they want

if u use 33 in minecraft i'll get a piston

[rustic rain]

they don't know id

[rotund token]

that's up to you

[rustic rain]

that's why I want to have string/prefab

[rotund token]

how is string any more useful than an ID

they dont know the string ^_^'

string is just an id

[rustic rain]

because I still don't see how user would get an ID of prefab

because as for string

user will manually write it

[rotund token]

your string is ID

[rustic rain]

yes

[rotund token]

they can manually write an int the same way they can manually write a string

do they not have numbers on their keyboards

[rustic rain]

but there are supposed to be many modders

so the odds they pick same numbers

welp, kind of high

[rotund token]

dude just literally said the prefab already exists

so you've set these ids up

[rustic rain]

well, the best I see is just keep another hash

for string/id

but that's just extra step

[rotund token]

^

[rotund token]

^

these are contradictory

[rustic rain]

Modder is supposed to be able to create prefabs, even without assembly

[rustic rain]

so game loads those prefabs and uses them automatically (or not)

[rustic rain]

but modder does not have any reference to that prefab

[rotund token]

i just went through this with you
i was providing a solution to have users create prefabs

then you said, users are not creating prefabs

they already exist

[rustic rain]

Modder creates prefabs and serializes them so then game loads them

but he is not meant to have control over loading process

[rotund token]

in which case ^

thats all you need

i don't get it

you just need a way for a user to register a unique id to a prefab

[rustic rain]

string

[rotund token]

a string is an id

i dont care if your id is a string, int, long, texture, or biometrics

id does not mean int

[rustic rain]

I kind of assumed it is, kek

[rotund token]

my ids are 4 longs

in guid format

[rustic rain]

hmm

when game object prefab is getting converted

I guess prefab is not taken in account in any way?

conversion systems probably just process it without any regards for prefab

[viral sonnet]

i love quoting out of context

😄

that weakreference script is a blast from the past. tertle, can you remind me why they were setting it up like that?

[rustic rain]

During conversion is it possible to get reference to actual target world?

I have extension fields in it I would like to fill

During conversion

I don't really want to create additional system with query

Welp, seems like I do need it

Sadge

[rotund token]

Probably to not worry about cross scene references

Back when you get to register all your ghosts (I'm not sure this is the case anymore)

[rustic rain]

Are entity references in fields resolved during conversion?

Basically if I create Entity in conversion system

that will have component that references other entity

after it's copied into actual world

are references remapped?

[rotund token]

are these other entities in the conversion world?

if so yes things should remap

[rustic rain]

I need to create copy of entity, add prefab tag to it
And save it to other entity as field in comp

all will be created in conversion system

[rotund token]

is this runtime conversion?

[rustic rain]

subscene too

both

I'm also still can't figure out how to resolve it all correctly

I want to have GO prefabs with special authoring component, which will be responsible for solving copies

so if let's say you spawn 10 GOs with same authoring component's value

only 1 copy of them all will be written as prefab in World

and this also for subscenes

so once world is started and running, all existing entities that are spawned from prefab will have it's link

so that I can restore them later during save/load

based of these prefabs

[rustic rain]

Is updating in [UpdateInGroup(typeof(InitializationSystemGroup))] ok?

Does it update same way as in editor?

[rotund token]

yeah

[rustic rain]

so in short it's just a system that updates before simulation?

[rotund token]

yes

[rustic rain]

btw, can it be bursted?

These attributes are somehwat confusing

since some of them say BurstCompatible

other say structuralmethod

[rotund token]

should be fine in burst

[rustic rain]

bruh

InvalidOperationException: SolvePrefabsJob.query.__impl uses unsafe Pointers which is not allowed. Unsafe Pointers can lead to crashes and no safety against race conditions can be provided.

why EntityQuery methods have BurstCompatible attributes

if safety checks won't even let you use them in jobs

hmmm.
Wonder if I should rely on Transform parenting system

or just work with world coordinates

even if they are wonky and huge

[rotund token]

burst compatible

does not mean job/thread safe

these were all made burst compatible for ISystem

[rustic rain]

oh

maybe I'll just do ISystem then

yay, it works

[rustic rain]

hmmm

Do I need to specify every method for BurstCompile or?

For some reason simply tagging struct as BurstCompile doesn't work

in ISystem

[rustic rain]

oh man I start to really enjoy fully unmanaged ECS world

no need for any references between systems

just do EntityManager extension

and do event entity

[rotund token]

for ISystem you need to tag the struct but also the OnUpdate method

tagging OnUpdate actually makes that method compile bursted
while tagging the ISystem struct just gives burst a hint where it needs to look to compile a method

it's too costly for burst to simply try inspect every method in a project to see if it needs compiling

[rustic rain]

I see

will other methods like OnCreate or OnDestroy be bursted though?

[rotund token]

no

well if you put it on those methods then it probably would

i've never actually tried though tbh

i usually have managed code or unburstable code in OnCreate

like GetEntityQuery is not burstable

[rustic rain]

yeah, it's ok

[dense crypt]

I heard it's supposedly possible to debug jobs with breakpoints nowadays, do I need to do some special setup to make them work? Because just putting a breakpoint doesn't seem to trigger it. I'm using Rider.

To add to above,, disabling Burst Compilation makes it work properly, but I was under the impression that "Native Debug Mode Compilation" would do something similar for me

[rustic rain]

NativeDebugger

tertle said VS has one

I haven't tried it yet

[dense crypt]

Oh right, Native. I see the issue now, that explains why it doesn't work on Rider's normal debugger

[rustic rain]

oh god, treating shared components as managed feels awful

so many workarounds

I feel terrible

[nova river]

Hey guys, just getting started with Unity & DOTS. Tried following the new ECS project video (https://www.youtube.com/watch?v=m_ZDL2X9jvM&t=1s ) to get started and I can't get a baisc 3d object to convert and render in my game window in play mode. Using Unity 2021.3.6f1 and Hybrid Renderer 0.51.0-preview.32
Based on the DOTS hierearchy, the object is being converted correctly, but I don't think its rendering.
Anyone have any ideas?

[rustic rain]

ahem

is calling World from SystemBase is a sync point?

[viral sonnet]

What are you calling from it? I'm not aware of any sync points.

[rustic rain]

between scheduling of jobs

[viral sonnet]

what data do you get from it?

EntityManager?

[rustic rain]

nah, just extension field

I won't be able to check anything though, because I already moved everything to callback events that assign data instead

[viral sonnet]

huh, well, I dunno. Just calling World is not a sync point. It just returns you the unmanaged world object

in general, only certain methods have sync points from EntityManager and some forms of schedule like with change filter. most are quite obvious though

and when not obvious, running the game will give you errors when you rely on schedules

[rustic rain]

It returns Managed world

tbh

I'm not sure what actually causes errors at this point

so I'll just leave it behind until I face it again, kek

[viral sonnet]

the managed world is mostly a wrapper afaik

[rustic rain]

yeah, but you can extend it

I already overabused the power of it

[viral sonnet]

hehe

[rustic rain]

xD

[pliant pike]

Has anyone else come across this error Assets\Scripts\FlowFieldGridStuff\CalculateCellCost.cs(10,5): error SGICE002: Seeing this error indicates a bug in the dots compiler. We'd appreciate a bug report (About->Report a Bug...). Thnx! <3 System.IO.IOException: Cannot create 'Unity Projects\LOR Tower Defence Test Scene\Temp\GeneratedCode\Assembly-CSharp' because a file or directory with the same name already exists.

it appears my project is completely broke now it won't compile anything and I don't know what to do 😕

[calm edge]

I'd close unity and nuke the temp folder

[pliant pike]

ok I think its fixed now thanks

[rustic rain]

Is casting to IEnumerable<T> burst compatible?

I kind of don't want to write utility method for literally all native containers out there

[haughty rampart]

try it out

[void ravine]

Close unity
a rename the project folder to not have spaces in the name
delete the Temp folder
try to reopen the prject

[pliant pike]

I think it fixed itself but if it happens again I'll try that, thanks

[rotund token]

You don't need to close unity to fix this error

Just load up the temp / code generated folder

Delete the files in that

Reimport a script to trigger a recompile

For some reason the code gen is creating files instead of folders sometimes blocking the folders being created

[pliant pike]

ok, that's good to know

[drowsy pagoda]

Is there a safe way to write to an ISystemStateComponent collected from CDFE which was plugged into an IJobEntityBatchWithIndex.ScheduleParallel()?

[rotund token]

can more than 1 thread write to the same one?

or does your logic prevent it

[drowsy pagoda]

I get error that that CDFE<StateComponent> is not declared as ReadOnly, container does not support parallel writing.

Is that something I can "make" it support? Or I have to schedule single?

[rotund token]

if you have 2 separate threads writing to the same entity

it's just not safe

so that's why it's prevented by default

[drowsy pagoda]

If I want to get around it, I'd need to use NativeDisableForParallelRestriction type deal?

[rotund token]

yes

you're telling unity that you promise you aren't doing something unsafe

but it's up to you to ensure that

[drowsy pagoda]

And say another thread writes to it at the same time, will it silently overwrite, or will it throw exceptions?

[rotund token]

there will be no safety for you

the result will be undefined

in theory you could end up with half the value from 1 write and half from the other write

unity will not tell you this is broken

you have to be certain this situation can't happen

i.e. you should never do this unless you only map 1:1

if you are just writing randomly then this is not safe

[drowsy pagoda]

I see, yeah best not to mess with that then.

[rotund token]

if you had like single fields to modify, you could do things with interlocked etc to write safely in parallel

but you need to be comfortable with what you're doing otherwise turning off safety is a really easy way to cause yourself rare random bugs that are extremely hard to track down

[drowsy pagoda]

interlocked etc, meaning lock (myField) { // execute write here } type deal?

[rotund token]

interlocked as in

Interlocked.Exchange|Add|etc

[drowsy pagoda]

I think this is new for me. Can you give me more info?

[rotund token]

https://docs.microsoft.com/en-us/dotnet/api/system.threading.interlocked?view=net-6.0

microsoft do a better than i ever would

[drowsy pagoda]

Woah, narly!

So here is the part in the job that I need to write back. How would I perform this Interlocked technique on this?

var treeState = unitStateComponents[directive.TargetTree];
treeState.health = math.max(0, treeState.health - toolPower);
unitStateComponents[directive.TargetTree] = treeState;

[rotund token]

will never work

not with the max

you'd have to remove the max

and have another job later apply it

in the time you read
Read: treeState.health
Execute: math.max(0, treeState.health - toolPower);
Write from another thread: treeState.health
Write this thread: treeState.health

[drowsy pagoda]

I see

[rotund token]

firstly you need a custom extension for ComponentDataFromEntity that will return the value by ref/pointer

then call Interlocked.Add(ptr, -toolpower)

and it would safely sum all threads

then you'd need a second job to go over all healths and do a max(0) on them

[drowsy pagoda]

I think I'll just chain jobs, Schedule Parallel all the calculations, and Schedule Single (dependency on parallel completion) to apply changes in calculations.

[pliant pike]

I don't suppose anyone knows how I use a CollisionFilter so that a raycast or an overlapsphere only hits on specific groups

I've got the raycast sort of working correctly by getting the filter from environment entity's

but the overlapsphere I need it to exclude the environment but I'm not sure how I set it up to do that

[rotund token]

if the environment in its own layer?

[pliant pike]

yeah

does physics entity's actually use the layers?

I thought it only used the belongs to and Collides with Collisionfilter thing

[rotund token]

they are the layers

[pliant pike]

so its something in the way I have it setup

I have the environment that collides with both enemies and environments

and I have enemies that only collide with the environment

so if I get the collisionfilter from the enemies then that means that cast should only collide with the environment? 😕

so I probably need to either create a new object that only collides with enemies or manually create a collisionfilter but the filter is kind of confusing because it uses uint

I wish I could get the names of what the values are because they don't seem to correspond to what they should

[pliant pike]

I think I did it

I created an entiy and it had to belong to the environment and only collide with enemy's

[dense crypt]

Isn't the Burst Inspector supposed to show pieces of your original code in comments? Currently I have a simple Entities.ForEach and the Burst Inspector ASM is >10k lines, so I'm not really sure where my ForEach is or how I can locate it

I find all sorts of code gen stuff for grabbing components from chunks but I can't find the actual code that I wrote

[rotund token]

reading through very fast 😄

usually in middle 3rd

[rustic rain]

hmm

I assume there's no ReadOnly version of array or lists in native collections?

btw, is accessing field as ref is that simple?
ref var galaxy = ref World.galaxy;

[rotund token]

there is totally a NativeArray<T>.ReadOnly

[rustic rain]

oh

[viral sonnet]

yes :)

[rustic rain]

oh god

I could have made things so much easier

[viral sonnet]

ref is pretty cool. best feature in modern c#

[rustic rain]

bruh

GetEntityQuery is protected of SystemBase

[frigid crypt]

I have a question, is there any tutorial or something that showcases how Joints work with DOTS and Unity Physics?

[rustic rain]

samples

[robust scaffold]

Ugh. Back and forth, back and forth for days and weeks now. I think I might roll my own 2d physics engine as well. That way I no longer have to touch GOs at all

[rustic rain]

you can use 3D engine tho

just set up constaints

and should be good

[robust scaffold]

Sliding across surface stability. Dots Physics doesnt have that

It's pretty noticable in that DOTS UI video with the 2d sample game. The enemies bunched together would vibrate in position against each other due to the lack of stable collisions.

And plus performance. Why model 3d physics mesh when 2d is what is needed

[viral sonnet]

performance difference is not that big between 3d and 2d physics. depends on shape I guess. usually a bunch of standard shapes is enough to model something

[robust scaffold]

Just circles and squares. A bunch of them but just those 2

Maybe polygons but I can make them out of a bunch of squares. Tilemap colliders

[rustic rain]

well, tbh

[viral sonnet]

then it doesn't matter really. but what's your issue, the sliding or more?

[rustic rain]

3d should be fine perfomance wise

if you only use cubes, spheres

and etc

[robust scaffold]

just the sliding. I know Havoc has contact welding which will probably solve the issue but Im also dipping my toes into multiplayer. This is just a proof of concept project where I'm just touching upon various areas of game dev for a surface level understanding

[robust scaffold]

Ya know, I wonder what's going on in Unity DOTS team. They've gone back to radio silence on many of the forum posts. Except for netcode though. They were still active even before 0.50.

Or they could just be on summer vacation. The europeans have those strange things.

[rustic rain]

It is hot in europe during summer, kek

[rocky dove]

Inside an Entities.ForEach(), is it bad to then call a static function and pass the components as arguments?

[rustic rain]

not at all

it will be inlined

in burst at least

I personally do it for like 80% of all logic, xD

[rocky dove]

Thanks dude

[tribal helm]

Hi everyone, I currently have an issue with entity generation. When I try to generate it with a script (the script get mesh and materials to generate an entity with this), it just doesn't render at all (I'm running the script on an empty GameObject).

I'm running on 2021.3.6f1 with experimental packages:

• entities
• hybrid renderer
• unity physics

All packages are version 0.51.0-preview32.
Any advice would be greatly appreciated

Here my script```cs
public class WorldManager : MonoBehaviour
{
[SerializeField] private Mesh unitMesh;
[SerializeField] private Material unitMaterial;

void Start()
{
    float3 position = Random.insideUnitSphere * new float3(100f, 100f, 100f);
    quaternion rotation = quaternion.Euler(0f, 0f, 0f);
    float3 scale = Vector3.one;

    EntityManager entityManager = World.DefaultGameObjectInjectionWorld.EntityManager;
    EntityArchetype archetype = entityManager.CreateArchetype(
        typeof(Translation),
        typeof(Rotation),
        typeof(RenderMesh),
        typeof(RenderBounds),
        typeof(LocalToWorld)
        );

    unitMesh.bounds.ToAABB();
    Entity myEntity = entityManager.CreateEntity(archetype);

    entityManager.AddComponentData(myEntity, new Translation
    {
        Value = new float3(2f, 0f, 4f)
    });

    entityManager.AddSharedComponentData(myEntity, new RenderMesh
    {
        mesh = unitMesh,
        material = unitMaterial
    });
}```

[rustic rain]

try using utility method

RenderMeshUtility I think it's called

it will add all required components itself

[fleet quartz]

Relatively new to Unity here. Is DOTS available and ready for production?

I heard it got canceled or something but maybe that is bad info

[coarse turtle]

Entities is still in preproduction - but 1.0 release is coming to a later release in 2022.2 beta. Burst & Job System that ships with the editor are ready for production

[fleet quartz]

All the Unity news lately has been confusing to me

[tribal helm]

So, I have all the components with RenderMeshUtility, but it doesn't render

[rustic rain]

check in hierarchy window

system relationship

is it affected by HybridRenderer?

[tribal helm]

system relationship in hierarchy ? I don't have it

[rustic rain]

window-Dots-hierarchy

[tribal helm]

oh

thx for this info

[misty wedge]

Anyone else have issues with unity using a lot of RAM? Each time assemblies are reloaded it seems to use more

https://i.imgur.com/w7cHKCX.png

[viral sonnet]

Just read the DOTS forum. All info is stickied

[rustic rain]

Brrruuuuh
Feels so bad having no 2d transform

Now I'm between 2 fires:

1. Make 2d transform and renderer
2. Make it all on 3d through constraints with very little chance to easily refactor it

[rotund token]

Is there actually a reason you're sticking with entities? It doesn't really seem to meet the needs of your project atm @rustic rain

[rustic rain]

Why wouldn't I?

I need a large simulation

[rotund token]

What is it giving you? From what I understand you're mostly hybrid and using 2d

[rustic rain]

With scaling capabilities

[rotund token]

You can still write a large simulation with burst and jobs without entities

[rustic rain]

No hybrid

[rotund token]

Oh you scraped all that?

[rustic rain]

Those are different projects

The other one is finished actually

[rotund token]

So confusing 😩

[rustic rain]

There's runner game with cannon and there's space tycoon

Cannon is done

Tycoon is in progress

[tribal helm]

Ok, for those who encounter the same issue, I was doing wrong on many points
First: I used a simple 3D template. We need URP or HDRP for the SRP(Scriptable Render Pipeline)
Second: I used basic material, we need to create material in the URP and NOT using default material
Third: I'm braindead

Thx @rustic rain for you help, you were really helpful

[drowsy pagoda]

Is there a built in way to detect when entity came/left into/from camera view? If not, can someone give me some pointers on how to go about this?

[rotund token]

it's a shame there is currently no easy way to hook into HR culling as far as i'm aware to get this info

but you can just do your own frustrum culling if you need

[drowsy pagoda]

Shit. I was afraid someone was gonna say that. Ok, how would one do their own frustrum culling. What formulas/API do I need for this?

[rotund token]

FrustumPlanes in Unity.Rendering has methods for you

pretty straight forward

FrustumPlanes.FromCamera(Camera camera, NativeArray<float4> planes)
then just call
IntersectResult FrustumPlanes.Intersect(NativeArray<float4> cullingPlanes, AABB a)
to do a check

[drowsy pagoda]

Awesome thanks.

[drowsy pagoda]

Hey, thanks for showing me this. Although it wasn't needed then, I sure ended up needing it now since we can't lock structs and all 😉

[rustic rain]

hmmm

I am doing a UI-World connection in which I want to create UI data after certain action

but what if Entity gets destroyed, on which this UI is based

is there some kind of way to have callback?

or simply checking whether Entity is legit on every update is the way?

[rotund token]

you can create your own 'callback'

but apart from that yeah you need to check

i have a standard destroy/cleanup pipeline

that every entity goes through

and things can check if an entity is going to be destroyed and do cleanup on it

but even this can become a complicated mess at times

[rustic rain]

well yeah, that would require creating quite a lot of systems for callbacks

I guess it would be easier to just check every frame whether it's valid

while bursted it's pretty inexpensive

glad I learnt how to use ISystem

kek

[rustic rain]

hmmm

I just figured an interesting approach to handling UI and fields

can make some Component with float field and also attach VisualElement to it (text for example)

and then if that float field is written - other system will rewrite it as string to text object, while filtering change version

UI systems will be responsible for creating such queries

I guess they can be separated with shared component of value of certain screen reference hash

so by filtering you can find any singleton entity

[molten flame]

I have a need to generate a bunch of dynamic physics objects but with random scales.
These objects need to be spawned at runtime from a prefab because they are networked ghosts.
Because Unity bakes in the scale at authoring time for dynamic physics objects I need to create these prefabs at authoring time, so there could be quite a few.
It'd be nice If I could automate this process to create a bunch of baked prefabs to leverage the authoring systems.
Has anyone done this before, i.e. baking prefabs from an authoring script during conversion? especially in a NetCode context.

[rustic rain]

why can't you just author what scale component you need and then run a job on your entities setting scale randomly?

[rotund token]

do you mean scale them during authoring?

[rustic rain]

no, just assign the component

and then during instantiation

you set the value

[rotund token]

that won't update the collider

[rustic rain]

composite scale?

[rotund token]

sure that works?

[rustic rain]

I think? xD

gotta test

[rotund token]

(see I thought it did but I can't see how it can since I see no references in code except in physics smoothing)

(the CreateRigidBodies job does not have a reference to any scale)

[rustic rain]

well, composite scale does exist for some reason, kek

and it's automatically added to entities with colliders

so I'd guess the easiest would be - just test it

[rotund token]

well its a transform component not physics

and yeah its only used as part of smoothing, so yeah not sure

[molten flame]

If I could do it at runtime that'd be a lot easier but I'm pretty sure the scale is baked into the physics geometry during conversion

TBH its probably easier to manually create a few variations with different scales and randomly choose from those.

I'm not big brain enough to go toe to toe with the DOTS gods like you guys XD

[rustic rain]

Have you tried composite scale tho?

I highly doubt Unity added whole damn another scale component just to adjust drawing

It's a pain working with two already

Let alone 3

[rotund token]

why don't you just create them at runtime as needed?

as long as client/server both add the physics components the same way should be fine?

[rustic rain]

I assume components version filtering only works for chunks?

Meaning if one entity has changed whole chunk will pass?

Not a good thing in my case since it will probably recreate whole UI

[rotund token]

you just use change filtering as a broadphase

you nearly always have to check individually entities yourself after this

[molten flame]

I could probably do this but I have no idea how to modify the collider to apply the scale.
I'm sure the conversion scripts can probably help but it might be entering too difficult to bother territory.
I'll definitely consider it though.

[rustic rain]

hmm

and how can I filter individual entity?

I'm really interested in trying to make this UI elements + Entities integration

for every named VisualElement there will be created entity with attached object

and by adding special components you can manipulate how values will be applied to those objects

[dreamy glade]

I've generated a bunch of voxel chunk entities from scratch but none of them have proper lighting/shading/shadows. Anyone know why this could be? They each have their correct components and component data when compared to test-gameobjects that I've then turned to entities that DO have proper lighting. Any ideas? Thanks.

[rustic rain]

mostly Text I guess

[robust scaffold]

ugh, unity's gonna make me implement my own sprite renderer arent they

[rustic rain]

we can combine our efforts

[robust scaffold]

im gonna give hybrid renderer a poke but last time I checked, it had enormous overhead

like 3-4 ms per frame rendering nothing.

[rustic rain]

what I think of it is

all you need is make a object dictionary

every time you convert object

with sprite renderer

you check whether sprite already belongs to some material

if it is

you just assign that material

[robust scaffold]

I literally render flat unlit textures. I roll my own lighting system. I just need a texture lookup

[rustic rain]

and then render instanced

ugh, sir

you can just use sprite material

lit/unlit

[robust scaffold]

I'm also rolling my own physics system in order to decouple the need for a game object entirely. However, I still need a sprite renderer.

[rustic rain]

just gotta figure what MTB properties belong to that shader

[robust scaffold]

Probably a custom SRP for that

hook it up manually

[rustic rain]

so in short it'll be:
grab all entities that belong to same atlas (material), grab their MTB (sprite UV) and then just pass that array to Instanced draw call

using quad as mesh

no need for custom SRP

just for that

in fact

Unity already rolled their implementation of it

you can look up sources on github

[robust scaffold]

Oh yea, hybrid has a sprite renderer implementation. Guess i can just copy and kinda customize

[rustic rain]

https://github.com/needle-mirror/com.unity.2d.entities/blob/master/SpriteRenderer/Unity.2D.Entities.SpriteRenderer.Authoring/ConvertSpriteRenderer.cs

no

it's different

it's for project Tiny afaik

[coarse turtle]

yea unity tiny uses bgfx as its backend for rendering

[robust scaffold]

Oh F tiny

Back when unity was optimistic in their dots development, before it got sucked into development hell.

[rustic rain]

well, as long as they release entities to 1.0

someone will come up with 2D

sprite rendering seems quite easy ngl