archived-dots

[viral sonnet]

Could be TempJob too. WorldUpdateAllocator is the more modern approach today

[spice vale]

How do you handle writing to same index twice? @viral sonnet

[misty wedge]

WorldUpdateAllocator is also cleared automatically, right?

[misty wedge]

That's why you need to recreate it each frame

[viral sonnet]

same index in 1 frame doesn't work.

i tried making a persistent NativeStream but it doesn't make much sense

[misty wedge]

Does the WorldUpdateAllocator automatically clear? And can it be used in a job?

[spice vale]

so If I have two systems producing damage events that can't work with nativestream

[viral sonnet]

it can work but the performance difference is nearly 0

sure, it's like a new alloc

[misty wedge]

So it's basically like a better tempjob

[viral sonnet]

yeah, you'd need 2 streams

[spice vale]

That's what I thought

[viral sonnet]

or you make sure with some form of index that it's only written once. but i don't see the point really

i also had the same problem, not really with damage but spells that are fired which can come from the caster, effects or triggers. i need 3 streams, well in my case custom parallel lists.

[spice vale]

I made a custom parallel blocklist implementation similar to the one dreaming has, for this reason

[whole gyro]

This is cool, thanks for sharing the code!
Couple of questions. It looks like you are iterating the target types and copying from the source to the target. Do you assume that the source has all of the components that the target has? And this doesn't work with dynamic buffers, right?

[viral sonnet]

i've used his blocklist too in the beginning. now i'm using https://github.com/enzi/Entities.Exposed/blob/main/Collections/ParallelList/ParallelList.cs

[rustic rain]

I set archetype before doing any of that

exactly same, so yeah

they have all same components

[whole gyro]

ah got it

[viral sonnet]

oh right @rustic rain what i wanted to ask. for the method you posted earlier you need to have the correct entity already and not a deferred entiry from ecb, right?

[rustic rain]

yeah, it's structural changes method

[viral sonnet]

doesn't look like it would scale that well

[spice vale]

@viral sonnet why the switch from a block list to list? Isn't block based list better?

[misty wedge]

What's the intended way to fetch system state entities? GetSingleton or use the systemhandle

[spice vale]

using system handle seems more robust

[viral sonnet]

to prevent allocation time

[spice vale]

but you get more allocations if your list grows?

[misty wedge]

That'd make the system run even if it doesn't exist though, unless you also require the singleton in oncreate

[spice vale]

But it should be created by the system in on create, no?

[misty wedge]

I never really do that 🤷 but it's certainly possible I guess

I'll try both and see what I like more

[viral sonnet]

i set the capacity so the resizes are minimal. also, reading and merging to 1 list is exceptionally fast

that's why i dropped the blocklist. reading and merging was so slow

[misty wedge]

Still kind of weird that if you stick state in a component it kind of breaks encapsulation, unless you also somewhat manage that state in the component itself, which isn't really in the spirit of dots

[spice vale]

I see, but to be fair with a block list you could just set the block size to your capacity and experience the same performance

[viral sonnet]

sure but it's not persistent so the alloc time will eat into the frame budget

[spice vale]

persistent?

[viral sonnet]

i've written it for a very specific reason. a parallel job writes data and then, due to race conditions, the data needs to be read in a single threaded job. the parallelList is best of both worlds for writing and then reading

[viral sonnet]

the parallel block list is created/alloced on every frame. the parallelList is persistent over several frames.

[spice vale]

not mine 😛

I can have it persistant

[viral sonnet]

that's good then! 🙂

i asked dreaming if he could make his list persistent but he didn't want to

the way it was setup is was quite annoying to rewrite

and as i meantioned before, the biggest problem i had wasn't with the writing but then reading. if you read in parallel, perfect. if you need to merge though, quite meh 😄

so much about high performance code is writing the right data containers that are perfect for the job

with burst i never had once a case where just instructions/arithmetics were a bottleneck. it's always data and data access

[whole gyro]

InstantiateInto

[pliant pike]

I've seen the same, it shows how good dots is and how it's pushing at the limits of the hardware, memory access is the bottle neck

[misty wedge]

Although I'm guessing that memory access is also already optimized in burst, I've never checked though

[spice vale]

An ugly workaround would be to reinterpret the state struct to another private one that the system can access that has all the system specific methods

[misty wedge]

I'll just manage the state in the component, I don't really care whether or not it's dots conform 🤷

[spice vale]

It would still be exposed to other systems tho?

[misty wedge]

To an extent sure. But if the methods are named and commented properly it makes it more clear what's going on instead of just have a single list in there

[viral sonnet]

just a few days ago i found a regression in one of my jobs. the job iterated on actors and processed combat events. for actors that only had a source event and no target event i had new timings of 2.5ms instead of 1.5ms. turned out when i rewrote my stat system i also acquired a stat byte* and read the health when it wasn't neccesary. well, i moved the data access and again down to 1.5ms. so, just that. reading a health value from a byte stream that's located in an IComp. (really inside the chunk, not outside so can't get any faster really.)

[spice vale]

mhm, I don't think this is anti dots necessarily

[misty wedge]

afaik you aren't supposed to have non-pure methods on your data containers in pure dots

[spice vale]

if they are simple its fine

[misty wedge]

Depends on who you ask

[spice vale]

just to improve the interface

[misty wedge]

I'm sure mindstyler would disagree

[spice vale]

well in that case, it should not be allowed to have any fields inside either, because those are just abstractions over the underlying bits

[misty wedge]

Well no, since it's only data

[spice vale]

just make all components empty, with an excplicit size lol

[misty wedge]

The point of DOTS is to separate state and behaviour

[spice vale]

an int field is not data

1 and 0 is data

[misty wedge]

an integer is just a type of data

Besides, I don't really care. I'll put methods in places if I think it makes sense

Unity breaks this convention in their code as well fyi

[spice vale]

I know, I'm on your side, just showing how absurd it would be if one followed that view dogmatically.

[misty wedge]

mindstyler has analyzers that throw compile errors if they put a method in an icomponentdata

[spice vale]

basically an int field can be seen as a method that takes the underlying data and reinterprets it as an int

[misty wedge]

That doesn't change the data though, so it's fine

[pliant pike]

According to the data oriented design book, if I recall and to be pedantic, everything in dots is kind of data including systems

[spice vale]

So system in component is allowed, nice 😆

[misty wedge]

Yeah it's definitely a design thing

Unity recommends no methods though, but again, they also ignore that same advice

[viral sonnet]

when a method is reused a bunch of times and code duplications starts to happen it's much better to put a method in a comp it is related to. (if it is)

could also go to a static method but for readability it's much clearer

[misty wedge]

Some people will die on the hill that that method should then be static

[rotund token]

You just cheat and put all the methods in extensions

[spice vale]

haha

[rotund token]

Everyone happy

[viral sonnet]

yeah extensions are much nicer

the biggest problem is how to make a dev aware that the method exists

[misty wedge]

Yeah I think at the end of the day everyone has to figure out what works for them / their team, a lot of it is too pedantic imo

[viral sonnet]

in teams i often had a problem where methods were written multiple times just because a dev wasn't aware of some dumb namespace

i mean, how should he?

[misty wedge]

I'm also very good at this and I'm not even developing in a team

[viral sonnet]

a lot is way too pedantic. namespace discussions alone. god damnit i nearly went mad sometime

like WHY in gods name do you care so much about how a namespace is called.

and why do we need 30 of them

[misty wedge]

Hey in the startup where I work people accept PRs even if the tests fail

[viral sonnet]

lol how does that happen? 😄

[misty wedge]

They click the red button that says "accept anyways" or whatever it's called on git 😅

[rotund token]

We accept prs when tests fail but you can't merge with a failed test

[misty wedge]

Oh, I meant merging

[rotund token]

Hard prevented

[misty wedge]

Not if you are admin

🙃

[rotund token]

I am the only admin

[misty wedge]

Well yes, I meant in my case

[rotund token]

But yeah that's dumb because if they're failing tests then once merged everyone will fail tests

[misty wedge]

exactly

[rotund token]

At which point just delete your tests

[rustic rain]

anyone figured this component?
RenderMeshArray

[misty wedge]

and then tickets take 5 times as long because everyone needs to fix the test and they have no idea whats going on

[viral sonnet]

don't test. EZ

[rustic rain]

I just don't get how to get Mesh out of it

correct mesh

[rotund token]

From memory issue it's just used to pass meshes to batch renderer

I don't think you do get meshes out of it

[rustic rain]

I need meshes out ofit

[viral sonnet]

btw. entity graphics has a huge regression with performance. if anyone's wondering, will be fixed in upcoming 2022.2 beta

[rustic rain]

or I need to be able to define RenderTexture to batch renderer

[rotund token]

That's not where they're stored

[viral sonnet]

related to the new batch renderer

[rustic rain]

but description literally says it is

also

I checked manually all entities

they do contain their mesh in this component

[rotund token]

Then use that component

[rustic rain]

but I can't figure a way to get index

sometimes correct index as is, sometimes it's index-2

I'm just confused

one example

the other example

red line is correct mesh

both at index one, but MMI value is different

🥴

[rotund token]

RenderMeshArray is not used at rendering time, it is used for loading baked entities.

If you would let me finish

[misty wedge]

Huh, you can't RequireForUpdate a system component?

[rotund token]

https://forum.unity.com/threads/how-to-replace-mesh-with-new-brg-api.1345112/#post-8493251

You probably want to read this

Material mesh info usually does not point to the mesh in the array

It points to the mesh in the brg

[rustic rain]

🥴

[rotund token]

To render in brg you must register your mesh

At which point you just have an index

[rustic rain]

already registered I guess

[rotund token]

And the whole thing is unmanaged

[rustic rain]

is there any tutorial on BRG?

I haven't really touched it

and I need it it seems

[rotund token]

You can change what you render by simply changing index

[rustic rain]

no no no

[rotund token]

The array is ignored once loaded

[rustic rain]

it's for selection system

[rotund token]

I know

[rustic rain]

I need to render things now

[rotund token]

I'm just explaining the system

[misty wedge]

https://docs.unity3d.com/2022.1/Documentation/Manual/batch-renderer-group.html

I thought the docs explained it pretty well

[rotund token]

See if the Entities graphic system has a method to get mesh

[rustic rain]

hmmm

so I create new

ok, I'll try to play with it

[misty wedge]

It's all there in the docs

Are system entities somehow different so they don't match a query?

[rustic rain]

oh bruh, I opened wrong doc

kek

[rustic rain]

system entities are just SystemState

all dropped in same archetype

[misty wedge]

Yeah, but they interact differently with entity queries

[rustic rain]

🤔

[misty wedge]

It seems you need to set an option on the query to find system entities

So similar to prefabs, I just didn't see any documentation on it

Btw, if I create a random entityquery somewhere, I don't seem to get any leak detection errors, even if I don't dispose it

[rotund token]

Queries auto dispose with world

They don't leak long term

[misty wedge]

Yeah, I just saw that

I wasn't sure if creating them using World also auto disposes them

so that's why

[proud jackal]

Actually you can RequireForUpdate(EntityQuery) is your option there if you have EntityQueryOptions.IncludesSystems.. And RequireForUpdate<T> will soon include it too, similiar to how GetSingleton works :3

[misty wedge]

Yeah I know, I just wasn't aware that the queries don't match them by default without the option set

[quick gazelle]

Queries created by GetEntityQuery or EntityQueryBuilder.Build(SystemBase or SystemState) will be disposed with the system. Queries from EntityManager.CreateEntityQuery or EntityQueryBuilder.Build(EntityManager) will be disposed with the World.

[misty wedge]

What happens if I write an extension method that uses the QueryBuilder api? Will the code-gen fail?

[proud jackal]

Depends on what you do with it I think it does cover the case of `SystemAPI.QueryBuilder().WithAll<SomeComponent>().Build().MyExtensionMethod()

[rustic rain]

EntityQueryBuilder is not codegen

I think...

[quick gazelle]

Not unless you use the SystemAPI version

[proud jackal]

^^^^ indeed (SystemAPI.QueryBuilder is, Unity.Entities.EntityQueryBuilder is not) :3

[misty wedge]

I'm talking about the code gen version of course 🙂

[misty wedge]

I meant more of an extension method for SystemState, e.g. RequireSystemComponentForUpdate, that uses QueryBuilder inside that method

[rotund token]

SystemAPI.QueryBuilder needs .RequiredForUpdate()!

[proud jackal]

SystemAPI support in utility methods is not yet a thing :3

btw RequireSystemComponentForUpdate<T> is just RequireForUpdate<T> soon tm 😛

[misty wedge]

Does anyone else have use for an OnFirstTimeStartRunning? I have having to check in OnStartRunning if this is the first run or not

[rotund token]

Just always update system

And early out from isemptyignorefilter

[misty wedge]

I'll need to do that on all queries though if I have multiple in the system

[rotund token]

Should be doing it anyway

To avoid setting up jobs with no entities in queries

[misty wedge]

But I'm lazy...

you keep forgetting this important facet

[rotund token]

Just always update system then without check 😅

Laziest way

[rustic rain]

wouldn't that create a lot of overhead?

[rotund token]

That's all require for update is doing

[rustic rain]

I mean

just the fact that it made it to OnUpdate

[rotund token]

The one important difference is if the system wouldn't run then you are adding overhead of dependency calls

[rustic rain]

there's OnBeforeUpdate

and etc

[rotund token]

But the point is more for systems that would be running nearly every frame anyway

But maybe not the whole system

[raw mica]

The docs around system components and system handles weren't ready for the experimental release but we're aiming for it to be in one of the upcoming releases before the final 1.0 so there should be time for feedback.

[misty wedge]

btw is there anything planned for some kind of serialization / save system for ECS? (before I write my own)

[rotund token]

or use mine in a few weeks! 😉

[misty wedge]

Ah cool, are you nearing a state you are happy with?

It looked really promising last time I saw it

[rotund token]

Oh its been in a perfect state for a few months

Haven't had to change anything

[hot basin]

is managed component support kinda reduced in 1.0?

[misty wedge]

Awesome, looking forward to it! 🙂

[proud jackal]

Yes and no, ConvertToEntity is gone so authoring is really hard, but to access managed stuff SystemAPI.ManagedAPI will be there as the Managed version of SystemAPI 😄

[hot basin]

and what is the best method to get entities from MB and to spawn entities from MB for now?

[proud jackal]

Ideally you should ask yourself first - Why are you accessing Entities in MB? Ideally you should use Systems to control your MB's from ECS data.
If you looked at all the options and decided to for some reason to stick to your opinion, then World.DefaultInjectionWorldSomethingSomething gives you the world, where you can get the entitymanager to access and edit your data.

[hot basin]

I want to spawn building ghost from UI - to be precise from button clicked event

and I'm using UI Toolkit if it helps

[proud jackal]

UIToolkit should totally still work in systems. Someone in here can explain how, as I've seen people already doing it :3
The gist is you need a managed reference (one thing you can do for that is in your MB Awake function do: var e = World.DefaultInjectionBlahBlah.EntityManager.CreateEntity() and then World.DefaultInjectionBlahBlah.EntityManager.AddComponentObject(this).
Then var e = SystemAPI.GetSingletonEntity<MyMonoBehavoiur>()

[misty wedge]

Yeah just grab all your stuff from the baked components and then its pretty much like a monobehaviour (e.g. set stuff on the ui document, etc)

[hot basin]

ok thanks for advice, I think I just drop foreach and do singleton instead, the problem was I can't make event lambdas inside Entities.ForEach

[proud jackal]

Ideally you should avoid using Entities.ForEach :3

[hot basin]

oh I can't SystemAPI.GetSingleton() on managed components

nvm, I can get it's entity

wow I can't even get managed component

[proud jackal]

And that's why SystemAPI.ManagedAPI is a thing comming soon tm :3 (for now use the fact that SystemAPI.GetSingletonEntity<T> does work 👀)

[hot basin]

but so what I can get entity if I can't get component from it?

[rustic rain]

dud, BRG is way too complex

and low level

[hot basin]

I mean, how to use this fact XD

[proud jackal]

So you get the entity and then use EntityManager.GetComponentObject 😄

EntityManager has mostly everything you need to both access, and change components, SystemAPI will just often be slightly faster, cause it can cache stuff (check source generated output to see it in affect) but nothing wrong in using EntityManager sometimes 😄

[hot basin]

thank 😄 completely forgot I can use EM 😄

@proud jackal thanks everything works now 😄

[proud jackal]

Yay! I'm glad :3

[hot basin]

why can I not resize buffer in Baker?

[viral sonnet]

huh? you mean setting the capacity?

[hot basin]

yes when I try this, it would throw bunch of strange errors in my subscene

var buildingBuffer = AddBuffer<TileBuilding>();
buildingBuffer.Resize(sizeSQ, NativeArrayOptions.UninitializedMemory);

and additionally it seems that accessing buffer by:

var tiles = ecb.SetBuffer<TileBuilding>(mapEntity);
var tile = tiles[id];
tile.building = entity;
tiles[id] = tile;

is breaking whole buffer

[viral sonnet]

resizing isn't supported in a baker. only at runtime. if you want a certain size, set the [InternalBufferCapacity(n)] of the IBufferElement struct

[hot basin]

size of buffer depends on another component value so cant use [InternalBufferCapacity(n)] and I'm using it with value of 0 as it's a huge buffer

but then why accessing causes it to reset/break?

[viral sonnet]

most likely the memory space is not setup

can you init the capacity at runtime when instantiated?

[hot basin]

buildingBuffer.Resize(sizeSQ, NativeArrayOptions.ClearMemory);

I'm doing this in initializing system now

what is equivalent of RequireForUpdate<>() in ISystem for singletons?

[viral sonnet]

most things are accessed through state state.RequireForUpdate<T>();

you can also use SystemAPI.GetSingletonRW<T>(); which sets a RW dependency for the scheduled job, not the Update call though

or without the RW, whatever you need

[hot basin]

but still this doesn't work

[hot basin]

thanks! ❤️

[misty wedge]

You need to append to the returned buffer. There isn't anything in it yet

What you are doing looks more like you should be getting a typehandle on the buffer on the entity, and then just modifying it instead of using an ECB

[hot basin]

strange, inspector shows that buffer has sizeSQ elements

[misty wedge]

SetBuffer is for replacing the buffer

not modifying it

[hot basin]

https://docs.unity3d.com/Packages/com.unity.entities@1.0/manual/components-buffer-command-buffer.html shows it is for modifying

[misty wedge]

Huh, interesting. I always thought it was for replacing the entire buffer with a new one

Is there a reason you want to do it with an ECB?

[misty wedge]

Tbh, looking at the source for SetBuffer, it very much looks like it returns an empty buffer

[hot basin]

oh maybe you're right

[misty wedge]

I can't see it reading the buffer from the entity anywhere

[hot basin]

I wonder, how to use ECB to change DB, should I do a Lookup and then SetBuffer() to override it at certain BufferSystem?

[misty wedge]

Why do you want to use an ECB? Why not just directly set the contents of the buffer?

[rustic notch]

Hi, I got this. Is there any solutions?

[misty wedge]

You can try attaching a debugger to the editor

[rustic notch]

Well I don't know where to set my breakpoints

[misty wedge]

You can pause execution and see where the threads currently are

[rustic notch]

Thx, I'll have a try

[misty wedge]

It rarely happens to me to, then I just kill the editor

[hot basin]

I change it to directly modifying DB but still shows the error

[misty wedge]

What's the error? And how are you changing it?

[hot basin]

nvm, this was a minor bug

it works with a lookup thanks a lot!

[drowsy pagoda]

I have a job that needs to look at a referenced entity (not the one being indexed) and use a ComponentLookup for that. It just so happens there is a condition that needs to check the same component against the entity being indexed.

My question is about performance. Is there a difference between:
A) Use both indexed entity and other entity in the ComponentLookup logic, or
B) Use ComponentLookup for other entity and use the in Component arg for indexed entity

[gusty comet]

How do you have a C# Attribute inherit another C# ATtribute? I'm trying to do somethiing like this

[UpdateInGroup(typeof(FixedStepSimulationSystemGroup))]
    [AttributeUsage(AttributeTargets.Class, Inherited = true)]
    public class BehaviorSystemAttribute : Attribute
    {

    }

So that I just label all my physics-related systems with [BehaviorSystem] and if I ever decide to switch away from FixedStepSimulationSystemGroup I can just modify the above code instead of changing every single system's attributes

[solar spire]

Can't you just use inheritance, not this?

Inherit from UpdateInGroup, if it's not sealed

[gusty comet]

Right, but I want to automatically populate it with a system group behind an abstraction. I ended up just creating a BehaviorSystemBase with the required annotations

[solar spire]

Would it not do that if your constructor set : base(typeof(FixedStepSimulationSystemGroup))?

[gusty comet]

That's perfect! Thanks!

Also, does FixedStepSimulationSystemGroup update like Monobehavior's FixedUpdate?

[brave field]

So even at SystemBase u should use idiomatic foreach starting at 1.0?

[molten flame]

Well it doesn't work for managed types so....

[deft pilot]

anyway to go from List<T> to NativeArray<T>?

[molten flame]

I don't think so, you just gotta loop and add em

[brave field]

Will idiomatic foreach support managed component at next release?

[deft pilot]

public struct FooComponent : IComponentData
{
  public BarComponent Value;
  public ValueTypeT GetValue => Value.Value;
};

is this okay?

cause otherwise code can become

myComponent.Value.Value.Value;

[spice vale]

There is a way, first you have to extract the internal array and then convert that to a native array. But you have to setup a few helper classes first.

[deft pilot]

i've just redid it so i don't need to do that

i'll ping you one day if i'm forced to do it

[spice vale]

Just check this repo if you ever want to do it, it's how I learnt it: https://github.com/Per-Morten/UnityUtilities

[deft pilot]

bookmarked for future

[dense storm]

How to properly destroy Entity properly when GameObject is destroyed?
I get this error : Destroying object multiple times. Don't use DestroyImmediate on the same object in OnDisable or OnDestroy.

private void OnDestroy()
{
  _combatEntityManager.DestroyEntity(_entity);
}

[spice vale]

but you are destroying an entity not object?

[dense storm]

Yes

[spice vale]

do you get that error message from destroying an entity?

[dense storm]

When MonoBehaviour triggers OnDestroy yep

Wait, could it be my companion link tries to destroy my GO as well?

Mono -> Destroy(Entity) -> Companion Link -> Destroy(GameObject)

namespace Unity.Entities
{
    class CompanionLink : IComponentData, IEquatable<CompanionLink>, IDisposable, ICloneable
    {
        public GameObject Companion;
        
        //...

        public void Dispose()
        {
            UnityObject.DestroyImmediate(Companion);
        }

        //...
    }
}

Yep, it destroys gameobject as well

[spice vale]

yeah but still weird that you get the error

nvm, I see what you mean

[dense storm]

Not sure how to do this properly hmm..

[rustic rain]

that's not meant workflow

so you'll have to create a bridge to entity world

either store EntityManager

and entity values in your GO

or switch to destroying GameObjects from Systems

[dense storm]

That's what I did, I have a Bridge singleton, and _entity is cached in GO.

[rustic rain]

what bridge singleton?

that's not smth I meant

[dense storm]

I see, so I have to create a system that destroys them

Ok understandable, when GO destroyed, add component data to the entity, and destroy from Entity world

[rustic rain]

no sir

that's not what I meant either

why is your GO even destroyed in the first place

the correct (ECS) way would be destroying entity this GO is attached to

[dense storm]

Game -> Main Menu transition

[rustic rain]

are you doing ECS or OOP?

[dense storm]

Hybrid?

[rustic rain]

ah, the worst 😅

well, from what I noticed, ppl do hybrid differently too

some do OOP game architecture while keeping some ECS elements or sub systems

some do ECS while using certain classic game objects with companion links

[dense storm]

I'll give it a try with system that destroys their entity counterpart.

[spice vale]

but that will destroy the gameobject

[rustic rain]

isn't that's the goal?

in perfect scenario - game object don't do anything but rendering

[dense storm]

Yep, that's the goal

[spice vale]

not sure it will work if you do like this "Ok understandable, when GO destroyed, add component data to the entity, and destroy from Entity world"

[rustic rain]

everything can be done from within ECS, unmanaged and bursted

[spice vale]

since you will destroy GO twice then

[rustic rain]

I thought he decided to create a ECS system logic that destroys entity

which is it?

[spice vale]

That works

[dense storm]

This, I'll try

[spice vale]

Just remember that dispose will be called on the CompanionLink as soon as it is removed or the entity is destroyed. So all destroying needs to happen from the ecs side.

[rustic rain]

🤔

I wonder if it's possible to make game object instantiation into entity burstable

or maybe Unity already did that...

considering enities with companion link get instantiated bursted right away

[spice vale]

Companion link and gameobject is managed, it can't be bursted

[rustic rain]

but game object itself is not

it's in c++ side of engine

which can be called from Burst

and assigning to entity component is done unmanaged, because it's just index

and assuming array/list of managed components is pinned

you can fill it out of C++ as well

[spice vale]

GO is just index? did not know that.

[rustic rain]

no

managed component on entity

is just index to managed component list

[spice vale]

mhm

[proud jackal]

Ideally yes! :3 - At least if you wanna future proof the project, as well as save yourself a lot of iteration time :3

[rustic rain]

idiomatic foreach?

is that Entities.ForEach(()=>{}) or smth else?

[proud jackal]

SystemAPI.Query

[rustic rain]

ah

but that's mainthread only, no?

or was that a case?

[proud jackal]

Indeed is!.. And IJobEntity is your threaded option :3

Entities.ForEach == bad comp time, and it also doesn't allow for normal syntax like continue vs return break etc.

[rustic rain]

bad iteration time?

last time I checked

it codegens into efficient IJobEntityBatch (0.51)

which was pretty much all required for best iteration

[brave field]

🥲 But currently idiomatic foreach I guess can't support managed component yet. Will next release have managed component support?

[proud jackal]

Indeed does.. But it's more a problem of CompTime, the dataflow analysis of capturing a lambda is really expensive.

[solar spire]

https://forum.unity.com/threads/exciting-developments-in-upcoming-entities-1-0-releases.1341071/ See idiomatic foreach

[proud jackal]

Normal managed comps are already supported, and UnityEngine.Component support is comming

[rustic rain]

you mean for compilation time?

[proud jackal]

indeed

[brave field]

@proud jackal btw how to increase idomatic foreach max 8 parameters limit without using aspect? Something like custom delegate for Entities.ForEach.

[rustic rain]

aaah, I didn't realise what you meant by bad comp time 😅

[brave field]

I guess u mean the time taken to scan Entities.Foreach code before codegen?

[rustic rain]

yeah

even my IDE struggles

when I click inside lambda here

offering me dozens of potential arguments

ripping perfomance

[brave field]

👀 The thing I dun like Entities.ForEach is u always want to create temp var just for Entities.ForEach to consume

[rustic rain]

Could you guys remind me what class/file is responsible for SystemAPI codegen?

I want to take a look myself and see whether I can implement my own solution

for codegen

[proud jackal]

The act of doing codegen on a lambda == sluggish. 😅 .. In anycase it also isn't really a nice pattern in general, not very normal foreach by design, the fact that you can't break is not nice to newcomers. It also expects newcommers to think threading is as easy as flipping a switch, which it kinda isn't. foreach->Ijobentity gives you a better idea of oh i should add a number here kinda thing. But I digress..

All sourcegen code can be found in com.unity.entities/Unity.Entities/SourceGenerators/Source paraphrasing the file path. Then you should find a solution called SystemContextSytemModule, which contains a SystemAPI.SystemRewriter 😄

[brave field]

I see but not sure newcomer able to understand or not that the query is reversed. Seems a little weird. Haha.
Btw how to increase idomatic foreach max 8 parameters limit without using aspect? Something like custom delegate for Entities.ForEach.

[proud jackal]

Currently not a thing, aspect is needed to do that :3

Or again, IJobEntity that can take N amount

[brave field]

🥲 So no plan to implement custom delegate for idiomatic foreach?

[brave field]

IJobEntity can make it run on main thread only?

[spice vale]

workaround could be to .ToEntityArray() on your query and do whatever on the entities, no limit on the amount of components you can access.

Btw @proud jackal how does idiomatic foreach compare to that approach?

does it have better performance? or just less boilerplate

[rustic rain]

it codegens into chunk iteration afaik

[late mural]

can i use memcpy to copy arrays from 1 place to another, and use size as TypeSize*LengthOfArray?

[spice vale]

but the sequence in which you access each entity should be the same, no matter if you use chunk iteration or iterate the entity array? So if memory access is the bottleneck they should have about the same speed?

[late mural]

i realise now that Stride is the proper term instead of TypeSize, but oh well

[spice vale]

yes you can but make sure that the source and destination are unmanaged or pinned managed arrays.

[late mural]

im mainly dealing with pointer arrays anyway, so that will be fine, thanks a ton!

[spice vale]

if your array is for example: IntPtr[] that is managed, and would need to be pinned before.

[late mural]

ah, no, rather i meant im using c style arrays, like:

int* IntArray;

[spice vale]

so did you allocate these yourself or?

[late mural]

im using a c api, it allocates them somewhere and gives me the pointers

[spice vale]

Ok, well as long as they don't move its fine.

[late mural]

they move sometimes, but always stay fixed if i tell them to using the api's map function, so it should be fine lol

[dense storm]

Why can't CompanionLink just have another bool parameter for DontDestroyCompanionObject

[rustic rain]

why should they?

companions are created with entities

what would be the reason for them to keep existing once entity is destroyed?

[dense storm]

Because sometimes we want to go 80% GO 20% ECS instead of the other way

[rustic rain]

🤔

then you might want to use smth other than companion links

[late mural]

im wondering does float3 have any function that does the same thing as Vector3.Scale()?

[spice vale]

its just normal multiplication on float3s

[late mural]

oh nice!

[spice vale]

in general any operation that works on floats, is now componentwise for float3s

[late mural]

ok that is really good, thanks!

wondering, which do you reckon would be faster:

SomeRandomVector3 += (Vector3)(SomeVector3 * SomeOtherFloat3)

or

SomeRandomVector3 += Vector3.Scale(SomeVector3,SomeOtherVector3)

also do you reckon it would be any faster if i put it in a job?

[stone osprey]

unitys ecs already has a way to enable/disable components right ? Or is this still wip ?

[late mural]

so far, from testing, it appears that the 1st one is much faster than the second one (not as fast as i would like though...)

[wicked trout]

Hi! (Sorry if I'm interrupting) I'm trying to generate Physics Bodies from script without using the Physics Body Authoring Component with a Subscene. I've added to the Entity all the necessary components: Translation, Rotation, Physics Mass, Physics Damping, Physics Velocity, Physics Gravity, etc. But when I press play the Entity does not move/fall to infinity. Is it because I need to add a Physics Collider or maybe Because I have to assign a Physics World Index? The Problem is I can't find a way to add an Index. Does anybody know how to do/generate it?

[spice vale]

Burst optimized for handling Unity.Matematics types so I would assume the first one would be faster for burst.

[late mural]

aha, ill add [BurstCompile] to the function then

anyway i can get tranform.forward as a float3 then?

[spice vale]

it can essentially do just one multiplication that works all elements at the same time, (SIMD)

math.forward()

[late mural]

ah i shall look into that then, thanks!

[spice vale]

yes in 1.0.0exp8

[spice vale]

or do you have a transform?

[late mural]

oh, ye it is a tranform

[spice vale]

then just convert the forward vector to float3

[late mural]

and that wont be too slow?

[spice vale]

I don't think so, I might be wrong but I think burst can optimize the cast away, since its the same data in vector3 as float3

[late mural]

ok, so a faster version would be this?

SomeRandomVector3 += (Vector3)((float3)SomeVector3 * SomeOtherFloat3)

[spice vale]

I think so

[late mural]

ill try that and report back, thanks!

wait are float3 and Vector3 the same in size and memory layout? As im dealing with pointers i might be able to just interpret the memory as a float3 assuming they have the same layout

[spice vale]

I think so, but not 100% sure

[late mural]

ill also test that then and see if memory stays good

[spice vale]

You can check the burst inspector and see what it compiles down to

[late mural]

burst has its own inspector? Cool!

[spice vale]

Jobs/Burst/Open Inspector

[late mural]

never heard of any of those lol, where would i find this burst inspector you speak of?

note im still in the 2021 version of dots for now

[spice vale]

OK, its somewhere in the top menu then

[late mural]

thanks!

yup found it

how do i find my function in this cursed menu lol

[spice vale]

you should be able to search for it

[late mural]

im trying, it can't seem to find it

[spice vale]

is your function static, has the burstcompile attribute, and its containing class has it too?

[late mural]

ah i didnt make it static, and the class doesn't have BurstCompile either

ill quickly do that, thanks!

hmm i dont think i can make it static unfortunately, is it required?

[spice vale]

for burst, yes. But you can make a job also, instead of a static method.

[late mural]

ah and then can i burst that job then?

[spice vale]

yup

[late mural]

good, thanks, ill try that and report back!

[spice vale]

you need a collider too

[wicked trout]

Alright thanks! I'll try it out.

[late mural]

making it a bursted job seems to be even worse for performance, odd

perhaps im doing it wrong though, ill send my code

sorry for flooding chat....

hold on ill just resend it as that pastebin site thing so i dont flood chat lol

https://hastebin-plus.herokuapp.com/tU8eRqgPn8

anyway, any speed improvements you can see?

[spice vale]

how long is the array?

[late mural]

the array can be anywhere from 0 to 30 thousand in length, it shouldnt matter much though right, cause it is just grabbing one index out of it?

[spice vale]

Scheduling a job has some overhead, so it only makes sense if you have a large enough array

[late mural]

ah unfortunate

[spice vale]

even just invoking burst code has some overhead, but for the most part that should be very tiny.

try using .Run() instead of schedule

[late mural]

ok i shall!

guessing i dont need .complete() then?

[spice vale]

nope

but wait, are you running this in a loop?

[late mural]

nope

and yup still way slower than just using the line i commented out

[spice vale]

So basically the operation you are doing is not expensive enough for it to be even worth running it in burst

its just a multiplication and add

[late mural]

unfortunate, what would be the fastest alternative then?

[spice vale]

just run it without burst

[late mural]

vector3's or float3's?

[spice vale]

doesn't matter really

[late mural]

float3's seem faster in my testing, so ill use them-ish i guess

at some point i would like to run this in a loop, but for now i doubt that is possible due to the odd way i setup my collision detection, thanks for all the help!

[spice vale]

if you would for example launch multiple particles at the same time, it would be worth doing a job that does that with a loop inside.

[late mural]

multiple particles can be in the trigger volume at once, but ive currently got it setup to run the method multiple times, rather than running it once with an array of all the particles in collision with the trigger volume, so eventually ill be able to make it more efficient, thanks for all the help! (for now it is a pain to change, cause everything else that relies on this collision detection system would need to be changed to make this work lol)

[open shore]

I want to make a simple ComponentSystem that runs once per frame in the same rate as MonoBehaviour's Update method. Which attributes do I need to add to the system?

[late mural]

ok finished converting everything to use nativelists, and do looping, any performance improvements anyone can notice? https://hastebin-plus.herokuapp.com/92dyDpbxX1

[spice vale]

if direction and power is always same you don't have to compute that in the job

[dense storm]

Anyone got a sample on how to display graphic with entities?

AddComponent<RenderData> no longer available, and don't know the new format

[spice vale]

no attributes required for that, by default they end up in the simulation system group which is ticked at the same rate as monobehaviour

[dense storm]

I just need to render basic mesh and materials without animations.

Creating entities from scratch need some pointers.

[open shore]

Awesome. What do I need to do if I want it to run before the fixed step group stuff?

[late mural]

unfortunatley direction changes a lot

[spice vale]

[UpdateBefore(typeof(FixedStepSimulationSystemGroup))]

[spice vale]

well in your job, it is constant

[open shore]

oh I thought I had to specify a system for that attribute good to know it works with groups too.

ty!!

[spice vale]

you are doing the multiplication for each index, when it is constant. Although maybe burst will realize that and just do it once.

[dense storm]

Found out informations about it https://github.com/Unity-Technologies/EntityComponentSystemSamples/blob/master/HybridURPSamples/Assets/SampleScenes/EntityCreationAPI/TestEntityCreationAPI.cs

[late mural]

oh, good point!

[late mural]

it might, although i would rather not take a chance on burst, unless there is a way of checking

so ill just do it once before the job and pass it

[frosty siren]

what is ScheduleParallelByRef in 0.51?

[deft pilot]

before i try this

can you have a buffer of buffers somehow?

or do i need a buffer of entities

which also have buffers?

basically trying to emulate List<List<T>>

[spice vale]

I think that is possible in 1.0.0, haven't tried tho

with like NativeList<NativeList<int>>

[misty wedge]

You will lose the ability to write to the inner list inside of a job though

[misty wedge]

What do you mean? What it does or what the function is called?

[deft pilot]

can you actually have NativeList<T> on a component

and not use IBufferElement?

[misty wedge]

You can, but the safety system will not let you write to it from a job

[deft pilot]

thats problematic

[misty wedge]

You can use an unsafe container or wait until unity manages to add this functionality to the safety system. But ideally if it's only a single native list you would use a dynamic buffer

[deft pilot]

okay i'll have to rethink my design for now then

see if i can flatten it

[misty wedge]

Is this mutable data? Or is it just for reading stuff

[deft pilot]

its like yes and no

weirdly

context wise

[misty wedge]

Also, a dynamic buffer already behaves like a List<List<T>> since you can have multiple entities with the buffer on them

[deft pilot]

yeah

but i need a link to them

wait

i see what you mean

[misty wedge]

You can store a reference to the entity

[deft pilot]

yeah

but thats what i just said

[misty wedge]

I mean it's not really a "buffer of entities", it's just entities

[deft pilot]

yeah

hmm

i'll go back to my drawing board for alittle bit

make sure this is absolutely necessary

[misty wedge]

You can also look into blobs, maybe those are better suited for your problem

[deft pilot]

hmm based on quick google don't think so

basically i have an entity that has 1 vector2 and a buffer of vector2s

i'm trying to store all the A* pathing outcomes for 1:Many of those

[misty wedge]

The first vector is the starting point and the buffer are the destinations?

[deft pilot]

yeah

hmm

okay i think i got it

i don't care about what the paths belong to

so i can just flatten this to 1d

just get the AI to pick a random path to use

wait no

that won't work i need to know the end

hmm

[misty wedge]

I'd just go the lazy route and use an UnsafeList<UnsafeList<T>> if you really need it all on 1 component

[deft pilot]

its okay

i just need another component

i think

okay i'll use index's as keys

that should work

makes it flat and i can reverse lookup both arrays

to get path and end point

since there will be N array elements for both

[spice vale]

Seems like it is not possible to destroy a GameObject from a system's OnDestroy() that's running in the editor world... Annoying... Anyone done this and found a workaround?

[rustic rain]

why not?

[spice vale]

no idea... seems like a bug.

[rustic rain]

what error do you get?

[spice vale]

when I enter play mode the editor world closes, so OnDestroy is called on my system and the GameObject is destroyed, but as soon as I exit playmode the GameObject is back again

[frosty siren]

what it does opposite to simple one

[misty wedge]

What the name says, it passes the job struct by ref instead of copying it

[rustic rain]

hold up, did you mean to remove GO from scene completely?

[spice vale]

yes

[rustic rain]

DestroyImmidiate

should od it

[spice vale]

I use that

[rustic rain]

you also should have gotten a warning

about it

[spice vale]

I know destoy doesn't work in editor

[frosty siren]

ok, so again it is about little performance gain

[spice vale]

but I use DestroyImmidiate

thing is, If I cache the GOs I want to destoy in a static list and delay destruction until the systems OnCreate is called once I exit play mode, they are destroyed fine.

[misty wedge]

Isn't that just because the scene was never serialized to disk?

It will load the old version would be my guess

[spice vale]

That sounds like it could be

Can you manually trigger serialization?

[misty wedge]

You can try marking it dirty and then saving

although maybe you can even skip the marking it dirty step, I think a direct call to save will do it regardless of whether or not it should

Ah yeah, there's even a note about it

[spice vale]

What method is that?

[misty wedge]

https://docs.unity3d.com/ScriptReference/SceneManagement.EditorSceneManager.SaveScene.html

[spice vale]

Thanks I'll play around with this and see if i can fix it.

[mild ledge]

I'm still super confused by the entities workflow. Why would I even do anything else than schedule jobs from a system if a systems update is main thread only

[misty wedge]

Because scheduling also has overhead, sometimes it can be faster to just do it on the main thread. Also you may need some previous data to schedule your jobs

[mild ledge]

I can do that in job and schedule the next job from a dependency. I mean I get a lets say MainPlayerMove system that moves my 1 player based on input to be just a Update on the system

but moving the 10k zombies that chase the player needs to be a job

[misty wedge]

It's up to you really. There's also some stuff that is just easier on the main thread if it uses managed types that haven't been converted to ECS

e.g. input system, 2d stuff, etc

[rustic rain]

some things are just super fast and require main thread

for example: player input

let's say player spawns entities

it's structural change, that can't be done in a job

so why create ECB, schedule it when you can instantly process input

and spawn entities

after all

all ECB run through main thread in the end anyway

[misty wedge]

Ideally in this case you would move your system close to another structural change

[rustic rain]

yeah

I have whole groups

dedicated to it

[misty wedge]

Yep, just letting them know that it's not super efficient to do that "between" two other structural changes

[mild ledge]

I get that. It's just most tutorials I see do for each entities in a system Update to move the enemies etc etc

and that seems like it should be in a job

input, spawning etc etc are ok on the main thread ofc

[rustic rain]

Entities.ForEach ... .Schedule()/.ScheduleParallel()
those?

they schedule codegened jobs

[misty wedge]

I mean the cool thing is you can always choose. e.g. IJobEntity has overloads for all types of scheduling, and can also be run on the main thread

So "everything" is already in a job, it just depends on how you are scheduling (or in the case of Run, not scheduling) it

[mild ledge]

" Entities.ForEach is fundamentally a job generator, and it makes it very easy to create parallel jobs. This unfortunately comes with a complexity cost and weird arbitrary constraints, which is why more explicit approaches are preferred. Those explicit approaches (IJobEntity) are covered later in this tutorial." I see

[misty wedge]

Also I would not use Entities.ForEach anymore, it is being deprecated in the next update

Use either the SystemAPI.Query API, or IJobEntity

(or IJobChunk if you want to be more explicit on what is happening)

[mild ledge]

I was talking about seeing many examples of ``` [BurstCompile]
public void OnUpdate(ref SystemState state)
{
// The amount of rotation around Y required to do 360 degrees in 2 seconds.
var rotation = quaternion.RotateY(SystemAPI.Time.DeltaTime * math.PI);

    foreach (var transform in SystemAPI.Query<TransformAspect>())
    {
        transform.RotateWorld(rotation);
    }
}```

[rustic rain]

this is main thread

[mild ledge]

this is not a job at all right

[misty wedge]

Yes, it runs on the main thread

[mild ledge]

regural everyday foreach loop

[misty wedge]

Well, burst compiled, so still very fast

[mild ledge]

well yes

[misty wedge]

Also has good cache coherency due to the the way the data is layed out, and does not allocate any garbage

[rustic rain]

don't take it too close to heart, unity themselves probably still haven't figured the best way to organise systems, so 😅

It's probably depends heavily on project too

[misty wedge]

Regarding your example, I would probably put that in a IJobEntity

[misty wedge]

But this is very true

[mild ledge]

I think I'm going to watch the 3 hours V rIsing stream

[misty wedge]

I thought they only used DOTS, not ECS?

I've still not gotten around to watching it...

[mild ledge]

bro at this point I dont even know the difference.... I've been using Jobs in regular projects for a while now

am I using DOTS ?

fuck if I know

[misty wedge]

DOTS = Job, Burst, Collections, etc

ECS = Entities, Physics, Graphics, etc

(vs "normal" MonoBehaviour stuff)

[mild ledge]

ECS is part of the whole DOTS stack as far as I can tell

[rustic rain]

I'd call it classic

[misty wedge]

Yeah that might be better

[rustic rain]

yeah, it's culmination of it basically

[spice vale]

No luck 😦

[rustic rain]

you are not required to use it

but ECS itself uses whole power of DOTS

[mild ledge]

but the guy in the stream starts talking about data oriented design so I guess they did ECS

[misty wedge]

Weird. Maybe it's the timing then? Are there any error messages?

[spice vale]

no errors

[misty wedge]

You can still use data oriented design for performance critical sections (and make it very fast using Jobs, Collections, Burst), without using ECS

[misty wedge]

Weird. I've never tried this, maybe you just can't save the scene while the game is already starting?

You could write a custom "start" script that does your cleanup stuff or something? Not the cleanest solution though...

[spice vale]

I was going to do that and leave it, but unfortunately its not only when entering and exiting playmode that causes the problem, but also when I close the whole editor and open it again, the GOs come back. I'll see if I can somehow manage a separate scene where I instantate my GOs to.

[mild ledge]

any official docs on how to use the new input system with ecs ?

[misty wedge]

There is no specific integration

So just use them separately, and modify the ECS state however you like according to your inputs

[mild ledge]

my idea was to have a InputData component that a system fills up. I'm not understanding how to get the InputActions connected to the system

[misty wedge]

Just read from them as you would normally?

[mild ledge]

from a monobehaviour ?

[misty wedge]

Why would you need a monobehaviour, just read from it in a system

[rustic rain]

there are couple of options so far I know

1. create a huge struct stored in NativeReference<T> and just access specific fields through pointer

2. use components for every action and it's state

for example

Started<RMB>
Performed<RMB>
Cancelled<RMB>

for now I use second approach, I do enjoy it
But it certainly has downsides

[misty wedge]

Why not just store the struct on a component

[rustic rain]

why not?

it doesn't change the fact that you will access it only once

kek

allthough

I see what you mean

[misty wedge]

Accessing it by pointer sounds more complicated than just reading a component

[rustic rain]

well, not really

NativeReference<T> is easy

it's like native array of size 1

you pass it by value

[misty wedge]

Yeah but why do that

Just put the state in a component on an entity

[rustic rain]

and then add dependency overhead for what?

it's input

written only once before World update

read only in World

[misty wedge]

If you want to micro-optimize that far sure

[rustic rain]

it's not even micro-optimization

it's just doing it simpler way

[misty wedge]

People using unity normally are often times not very familiar with pointers in C#

[rustic rain]

NativeReference<T> is easy

it's certainly better

than getting entity query for singleton

and accessing it through entity manager

every frame

[misty wedge]

So you mean just pass the NativeReference to the job

[rustic rain]

well, considering you usually use input for one time actions

you are probably just going to read it in OnUpdate

for some boolean for example

[misty wedge]

I know, but often times when you try to explain something you skip over details, and that makes it hard to understand what you mean

[rustic rain]

and then do early return if it's not

[misty wedge]

e.g. this isn't very clear

[rustic rain]

🤔

I guess

[misty wedge]

😅

Then yes, I agree, the approach you mentioned is easier, I originally thought you meant something completely different

Something I've been wondering, do ECBs do any kind of pre-processing on the requested commands? For example, if I add a component and then remove a component on an ECB, will it move that entity twice? or not at all?

[rustic rain]

should probably check source to figure that out

but I wouldn't count on it

since they specifically mentioned

that if you destroy entity in ECB

and then add smth to it

it'll throw

[misty wedge]

Seems kind of difficult if you have multiple systems that can e.g. destroy entities in an ECB

[rustic rain]

one more headache to look for 😅

[mild ledge]

Wait so I can use the generated c# class, new it in the systems oncreate and read inputs

[misty wedge]

Yes

[mild ledge]

Why the f didnt you say so🤣🤣

[misty wedge]

I assume you knew how the InputSystem worked 😅 this is the #archived-dots channel, not #🖱️┃input-system

[rustic rain]

inputAction.performed += _ => em.AddComponent(inputEventEntity, performed);

I usually do it this way

[misty wedge]

Alternatively you could try baking InputActionReference and reading the baked references, but I just read an instance of the generated C# class

[mild ledge]

We normally use this https://docs.unity3d.com/Packages/com.unity.inputsystem@1.0/api/UnityEngine.InputSystem.PlayerInput.html and invoke c# events this is why I was confused

[rustic rain]

well, that works too

but I tried it

and it sucks for all in ECS approach

because it's like combing OOP with ECS

result is uugh

so instead I decided to use all those callbacks

to just setup state in World

so systems can react on it

[mild ledge]

I still dont get your aproach

[rustic rain]

Here's simple toggle switch for example

    [UpdateInGroup(typeof(EarlySimulationSystemGroup))]
    [BurstCompile]
    public struct ToggleMapHandler : ISystem
    {
        private Entity _requestEntity;

        public void OnCreate(ref SystemState state)
        {
            state.RequireForUpdate<Performed<ToggleMap>>();

            _requestEntity = state.EntityManager.GetOrCreateSingletonEntity<Singleton<OpenMapRequest>>();
        }

        public void OnDestroy(ref SystemState state) { }

        [BurstCompile]
        public void OnUpdate(ref SystemState state)
        {
            state.EntityManager.AddComponent<OpenMapRequest>(_requestEntity);
        }
    }

everytime I press ToggleMap action button

it creates an entity with this tag

and this system runs OnUpdate just once

[mild ledge]

What is Performed<ToggleMap> and what does it do ? Somehow I still dont get it, thank you for taking the time to explain

[rustic rain]

just a tag

[brave field]

🥲 Sadly dots input is not a thing yet

[rustic rain]

emtpy struct

[mild ledge]

So who reads that for examole M was pressed to toggle the map ?

[rustic rain]

what it does - it exists the same frame Performed on ToggleMap action is called

[rustic rain]

that system above

state.RequireForUpdate<Performed<ToggleMap>>();

this makes this system run only if this component exists in world

and I clear all those components on end of frame

[brave field]

Really deprecate are next dots preview release? So fast. 🥲

[misty wedge]

In the full release at the latest iirc

[mild ledge]

But all the system does is add a component

[misty wedge]

Not necessarily in the next one

[brave field]

🥲 I still fixing compile errors of my production project. Can't enter play mode yet

[rustic rain]

well, it's just simple example

Here's more complex

    [UpdateInGroup(typeof(PlayerInputGroup))]
    [BurstCompile]
    public partial struct FocusOnPlayerHandler : ISystem, ISystemStartStop
    {
        private Entity _player;
        private Entity _cameraEntity;
        private EntityQuery _playerQuery;

        public void OnCreate(ref SystemState state)
        {
            var em = state.EntityManager;

            _cameraEntity = em.GetOrCreateSingletonEntity<SpaceCameraTag>();
            state.RequireForUpdate<Pressed<FocusCameraOnPlayer>>();

            _playerQuery = state.GetSingletonEntityQueryInternal(typeof(PlayerTag));
        }

        [BurstCompile]
        public void OnStartRunning(ref SystemState state) { _player = _playerQuery.GetSingletonEntity(); }

        // [BurstCompile]
        public void OnUpdate(ref SystemState state)
        {
            var em = state.EntityManager;

            var pos = em.GetComponentData<LocalToWorld>(_player).Position;
            var sysID = em.GetSharedComponent<StarShared>(_player).systemID;

            em.SetCameraPosition(_cameraEntity, pos);

            // Set star system if it's not already current
            if (sysID != em.GetEntityStar(_cameraEntity))
            {
                em.SetStarSystem(_cameraEntity, sysID);
                em.FixRendering();
            }
        }


        public void OnStopRunning(ref SystemState state) { }
        public void OnDestroy(ref SystemState state) { }
    }

state.RequireForUpdate<Pressed<FocusCameraOnPlayer>>();
So every frame this component exists

System runs

meanwhile this component gets created in Started and gets removed in Cancelled

of NIS callbacks

[mild ledge]

Ok I get it.. where do you hook into the nis callbacks ?

[rustic rain]

out of OnCreate of other system

[mild ledge]

And you use the genersted c# class there ?

[rustic rain]

            var inputActionTypes = TypeUtility.GetAllAssignableFrom(typeof(IEventAction)).ToList();
            _inputExtensions = TypeUtility.InstantiateAllOfType<IInputExtension>();

            foreach (var inputExtension in _inputExtensions)
            {
                var asset = inputExtension.Asset;

                inputExtension.RegisterCustomInput(em, inputEventEntity, pressedEventEntity);
                asset.Enable();
                foreach (var inputAction in asset)
                {
                    var name = inputAction.name.ToLower();
                    foreach (var type in inputActionTypes)
                    {
                        if (!type.Name.ToLower().Equals(name)) continue;
                        if (allStarted.TryGetValue(name, out var started))
                        {
                            inputAction.started += _ => em.AddComponent(inputEventEntity, started);
                        }

                        if (allPerformed.TryGetValue(name, out var performed))
                        {
                            inputAction.performed += _ => em.AddComponent(inputEventEntity, performed);
                        }

                        if (allCanceled.TryGetValue(name, out var canceled))
                        {
                            inputAction.canceled += _ => em.AddComponent(inputEventEntity, canceled);
                        }

                        if (allPressed.TryGetValue(name, out var pressed))
                        {
                            inputAction.started += _ => em.AddComponent(pressedEventEntity, pressed);
                            inputAction.canceled += _ => em.RemoveComponent(pressedEventEntity, pressed);
                        }

                        inputActionTypes.Remove(type);
                        break;
                    }
                }
            }

[rustic rain]

not really

I just iterate ActionMaps for InputAction

and automatically assign callbacks to them

name based

if type name and name of InputAction matches

I create all callbacks for all registered components

basically just for components that are used

but

I assume there's better solution

with just 1 giant struct

which contains all values for those actions

[mild ledge]

I assumed that for 1.0 at least input would work🤣

[rustic rain]

because this way you'll avoid any structural changes at all

[rustic rain]

lul

let's be glad we at least have character controlled for free

😅

[mild ledge]

For 0.5

[rustic rain]

well, 1.0 is not released yet to complain about it

kek

[mild ledge]

I can complain that there is no proper input handling in a 1.0 version even if its experimental

[rustic rain]

also no 2D, no animations, no audio

👴

[mild ledge]

1.0 means all the parts should at least be there but what ever just unity things

[rustic rain]

nnnah

it's just ECS that will be ready

everything else will probably be external packages

because I'm certain, those things will not do well with existing dev's solutions

[mild ledge]

Wdym no audio? Dots audio has been a thing since mega city they havent expanded on that at all ? Do i need to do magic trickery to play a bullet impact sound as well ?

[rustic rain]

oh, it's scrapped

you can use FMOD

it's burst compatible

since it's c++ native

[mild ledge]

How do you play sounds ?

[rustic rain]

you better read FMOD about it

in short, you just create event instance and use method on it

like

musicEvent.Play();

[mild ledge]

Fmod has ecs documentation?

[rustic rain]

no

it has nothing to do with ECS

[mild ledge]

So I pass the FMODUnity.EventReference to a component from the Baker I beleive it is called now and used to be AuthoringComponent and then from a system I can call the fmod runtime manager to play the sound ?

[rustic rain]

yeah, you pass eventReference and then you need to instantiate an event instance.
You can store it on component
Everything is unmanaged

which is pog

    [UpdateInGroup(typeof(InitializationSystemGroup))]
    [BurstCompile]
    public partial struct AddSoundInstanceSystem : ISystem
    {
        private EntityQuery _query;

        public void OnCreate(ref SystemState state)
        {
            _query = state.GetEntityQuery(new EntityQueryDesc
            {
                None = new[] { ComponentType.ReadOnly<SoundInstance>() },
                All = new[] { ComponentType.ReadOnly<SoundSource>() },
                Options = EntityQueryOptions.IncludeDisabled
            });
            state.RequireForUpdate(_query);
        }

        [BurstCompile] public void OnDestroy(ref SystemState state) { }

        public void OnUpdate(ref SystemState state)
        {
            var em = state.EntityManager;
            using var entities = _query.ToEntityArray(Allocator.Temp);
            using var sounds = _query.ToComponentDataArray<SoundSource>(Allocator.Temp);

            for (int i = 0; i < entities.Length; i++)
            {
                em.AddComponentData(entities[i],
                    new SoundInstance { value = RuntimeManager.CreateInstance(sounds[i].guid) });
            }
        }
    }

Smth like this

And then played like this

    [UpdateInGroup(typeof(InteractionSystemGroup))]
    [BurstCompile]
    public partial struct SoundInteractionSystem : ISystem
    {
        [BurstCompile] public void OnCreate(ref SystemState state) { }
        [BurstCompile] public void OnDestroy(ref SystemState state) { }

        [BurstCompile]
        public void OnUpdate(ref SystemState state)
        {
            state.Entities.WithAll<InteractedTag>()
                .WithAll<InteractionSound>()
                .ForEach((ref SoundInstance sound) => { sound.value.start(); })
                .Run();
        }
    }

[spice vale]

There is no reason to have a specific input system for dots, its not like input is a bottleneck in any game. Here is an example from unity of how to use the new input system with dots: https://github.com/Unity-Technologies/EntityComponentSystemSamples/blob/master/PhysicsSamples/Assets/Common/Scripts/DemoInputGatheringSystem.cs

[mild ledge]

Wait wait this is what I was looking for

[viral sonnet]

the argument is sound. i think that's also the reason why they dropped priority on audio. unity knows everyone uses fmod

[mild ledge]

Ofc unity hide the input example in the physics demos kekl

[stone osprey]

Soo not entirely dots or unity specific but im trying to replicate a pure c# archetype based ecs.
If anyone is interested let me know ^^ i think its pretty interesting, the current version is still very very basic but i already have a benchmark for the iteration performance.

[rustic rain]

Unity ECS is already pure C#

😅

[stone osprey]

Yeah but tied to unity, we cant use it outside of unity right ? ^^

[rustic rain]

no you can't

why not just use existing C# ECS libraries?

why invent a bicycle? 😅

[stone osprey]

Yep thats why i made my own one and for learning purposes ^^
Couldnt find any archetype based c# ecs... only sparsesets

[rustic rain]

well, pure C# without burst will not do well if you try to do it same way as unity

whole reason to return to monke do unmanaged code is because Burst

[stone osprey]

The main purpose was actually learning.
Yeah, "my" version does not use unmanaged code. But i try to utilize the L1 cache atleast ^^

I mean if you want you can take a quick look at it : https://github.com/genaray/Arch
Its not that much code, pretty small currently ^^

[rustic rain]

oof

well, I don't favor this approach because it's way too much GC allocation

for every little change in archetype

tons of allocated data

[stone osprey]

Interesting, let me hear... what exactly do you mean ? 😄

[rustic rain]

Unity chunks are unmanaged, no Garbage Collector involved

managed arrays are

[stone osprey]

Are thats what you mean, well yes... the only way to make it compatible with public struct MyData{ string s } components for example was to use regular arrays.
I also played around with a chunk variant that actually is unsafe and uses manual allocation of memory... i had the idea that the archetype could just support both, based on what the types are basically. If all of the passed types are unmanaged it could use the manual allocation approach and be more efficient probably

[rustic rain]

I'd say, just use Lists

for every type

[stone osprey]

I just wonder... if i can really utilize the cache with the current managed array approach. Since they are... managed... but every single person on this planet has a different opinion on this, most people actually told me that they are of course cache efficient

[rustic rain]

and figure a nice approach to iterate over them

[stone osprey]

But lists destroy the whole cache utilization idea 😮

[rustic rain]

no they don't?

[stone osprey]

Dont they ?

[rustic rain]

I actually tested giant array approach vs chunks approach

arrays won

List is just array with better handling

[stone osprey]

So chunks are not usefull ? Since the idea was... well... one chunk = 16kb, fits perfectly in the cache... insane iteration speed...

Therefore thats the iteration itself :

            ref var chunk = ref archetype.Chunks[chunkIndex];
            var transforms = chunk.GetSpan<Transform>();
            var rotations = chunk.GetSpan<Rotation>();
            
            ref var transform = ref transforms[0];
            ref var rotation = ref rotations[0];

            for (var index = 0; index < chunk.Capacity; index++) {

                ref var currentTransform = ref Unsafe.Add(ref transform, index);
                ref var currentRotation = ref Unsafe.Add(ref rotation, index);
                
                currentTransform.x++;
                currentRotation.w++;
            }

[rustic rain]

no, that's not the idea

I tested perfomance

in unmanaged context chunks are very versatile vs large arrays

so unless you want to hardcode access to them in your every system, just use chunks 😅

in managed scenario though

hmm

I'd guess your chunk can contain data about at what indices starts it's entities data in those arrays

[stone osprey]

Damn... but why ? I cant imagine a reason why one big array is faster than 😮
So chunks only make sense for unmanaged memory, interesting

[stone osprey]

Well each chunk has one entity array in it, i wasnt using it in the example above ^^

[viral sonnet]

look for BrokenBricksECS it was the ecs i used before unity released theirs

not relates to your question though. might just give you some ideas

[misty wedge]

If I'm using native streams and want to schedule something in parallel, do I need to set the index count to Threads * Chunks? Or can I check in a thread if the writer for that thread has been set to the correct index already

Also, I'm still not 100% clear on the usage. Do I pass the NativeStream itself to the job, then create a writer, or do I pass the writer to the job (calling BeginForIndex on the main thread)

[coarse turtle]

https://docs.unity3d.com/2019.3/Documentation/Manual/UnityasaLibrary.html you can use Unity as a library tho

not sure how it can be tied to packages

[viral sonnet]

you pass the writer to the job

in the job, use BeginForIndex before writing

i use the unfilteredChunkIndex for the index but that's up to you what you need. it's also possible to use the entity index if you need to group it per entity and not chunk

though that's a bit more tricky in 1.0 where IJobChunk doesn't have the entityIndex as parameter anymore

[misty wedge]

What do I set on native stream creation though then? Since each index can only be used once, it would need to be ThreadCount * ChunkCount right?

Also couldn't each thread just keep re-using the same index?

[viral sonnet]

chunkCount is enough.

[misty wedge]

I thought the indices can't be re-used? Or is that just after reading

Since I need to call EndForIndex after the batch is finished

[viral sonnet]

yes, but that would mean disabling the safety

[rustic rain]

whoah

that's some good stuff

[misty wedge]

You can write to the same index multiple times?

[viral sonnet]

you can write multiple times to the same index

yes 🙂

[misty wedge]

Ah, alright. I thought you couldn't

That makes more sense then, thanks 🙂

[viral sonnet]

that's why the reader returns a count when you start reading from an index

[misty wedge]

It just returns the same thing as RemainingItemCount right?

(once you set the index)

I'm trying to use streams more since they seem really useful for parallel operations where the total count is unknown (since the other parallel writers can't resize the underlying collection)

[viral sonnet]

yeah, afaik the remaingItemCount gets decremented with every read

yeah it does in ReadUnsafePtr, i have a while (stream.RemainingItemCount > 0) so it's fine.

[rustic rain]

🤔

[spice vale]

wait what? so you just never close the index then or what?

[rustic rain]

anyone worked with BRG yet?

I'm trying to understand whether I can render into specific RenderTexture

oh man, this API is so bad to work with

[viral sonnet]

like this ```inCombatStream.BeginForEachIndex(batchIndex);

for (int i = 0; i < chunkCount; i++)
{
inCombatStream.Write(...)
}
inCombatStream.EndForEachIndex();```

[spice vale]

sure, but after that you can't write to that index again, right?

[viral sonnet]

no, theoretically it would work but BeginForEachIndex sets the ElementCount to 0 so not with the NativeStream implementation.

[spice vale]

So basically you can write multiple times to the same index once 😆

[misty wedge]

That makes native streams really useless for IJobEntity then, unless you create a buffer for each entity which does not seem like a good idea

[viral sonnet]

correct 🙂 i must be misremembering this part - i thought i did this in the past at some point. how the code looks though, 100% not the case ^^

[viral sonnet]

hardly matters honestly.

[misty wedge]

What do you mean?

[viral sonnet]

opening an index for each entity is fine

[misty wedge]

Really?

[viral sonnet]

yeah, the memory block. m_BlockStream->Ranges is pre allocated beforehand

it's overhead, sure, but very small

[misty wedge]

Oh, opening an index sure, but I mean creating a native stream with that many indices

[viral sonnet]

yep, even that

[misty wedge]

Oh ok, I thought it was slow-ish due to this comment:
Using a job to allocate the buffers can be more efficient, particularly for a stream with many buffers.

I'm guessing using an IJobChunk with the unfilteredChunkIndex as the stream index is probably faster though

[viral sonnet]

sure it is, especially when reading then

        {
            long allocationSize = sizeof(UnsafeStreamRange) * forEachCount;
            m_Block->Ranges = (UnsafeStreamRange*)Memory.Unmanaged.Allocate(allocationSize, 16, m_Allocator);
            m_Block->RangeCount = forEachCount;
            UnsafeUtility.MemClear(m_Block->Ranges, allocationSize);
        }``` that's the part where the forEach ranges are allocated

i think 24 bytes per element

IJE has no chunk index? i'm very unfamiliar with it

[misty wedge]

nope

Maybe you can get it somehow, but it just has the read / write handles for the components normally as parameters

Nevermind, you can get it

[rustic rain]

yoooo, I figured how to do custom rendering now

😅

            var sys = World.GetExistingSystemManaged<EntitiesGraphicsSystem>();
            var fieldInfo = typeof(EntitiesGraphicsSystem)
                .GetFields(BindingFlags.Instance | BindingFlags.NonPublic)
                .First(x => x.FieldType == typeof(BatchRendererGroup));
            _brg = (BatchRendererGroup)fieldInfo.GetValue(sys);
var mesh = _brg.GetRegisteredMesh(mmi.MeshID);

[misty wedge]

The BRG in it is private?

[rustic rain]

yeah

[misty wedge]

[rustic rain]

yeah

well, it's not really an issue

sad part

I didn't figure how to draw with BRG

so I'll use legacy system

Entities graphics system is 3k lines

hope I won't need the same 😅

[viral sonnet]

huh that's kind of weird you have to do that

[rustic rain]

wcyd

technically, nothing stops you from registering generic types in runtime either

but to do that you have to use Harmony or some other code injection hack

[misty wedge]

won't work in AOT though

[rustic rain]

yeah

no il2cpp in this one

[viral sonnet]

and why are you doing this?

[rustic rain]

I use selection tool which needs entities rendered

with new API old way of getting meshes broke

so

fixing it now

hehe

[viral sonnet]

ah i see

[rustic rain]

in fact

it seems like the whole process is actually a bit easier now

if it wasn't for me being pepega for so long

allthough I might take back my words 😅

so I have entities in a chunk

each entity might have their own meshID

while I need in the end nice them groupped, so I can draw same meshes batched

🤔

I'd guess obtaining hashMap value on every entity iteration is not a good idea

[misty wedge]

Not too different from reading a component / buffer lookup

[rustic rain]

yeah, but I need it for very fast job

I need to collect all entities indices and transforms into 1 good looking array

while separated by meshID

but while iterating chunks I might get different indices every time

[rustic rain]

hmm

I'm checking at implementation of HashMaps rn

I need a hashmap to which I can write in a batch

<int,int> hashmap

where I need to write array of Entites as batched key,value pair

NativeHashMap seems like using some sort of integer between pairs

so that won't work

meanwhile UnsafeParallelHashMap makes me 🥴

[misty wedge]

Why do you need an unsafe collection

[rustic rain]

I was checking internal data structure

but it's so low level

I can't understand it

[rotund token]

Sounds like you want a hashmap of lists

[rustic rain]

that's what I do rn

but implementation I need is just 🥴

it used to be so cool when it was just 1 render mesh per chunk

now I need some complex map solution

I need this structure per batch:
uint meshID
float4x4[] matrices
int[] indices

any idea how I can implement one?

@rotund token

[hot basin]

any materials on BRG?

[rustic rain]

you can obtain any

using MMI component

[hot basin]

I mean "external materials" i.e. tutorials, something more on the matter than: https://docs.unity3d.com/Packages/com.unity.entities.graphics@1.0/manual/batch-renderer-group-api.html

[rustic rain]

?

you can add any to it

I don't use it to do selection rendering though, so

[hot basin]

?

I think "material" in this context may be misleading or plainly wrong. I'm asking for external sources on BRG like tutorials, articles etc.

something that explains it more than linked doc

[rustic rain]

ooh

xD

no idea, I only read manual

from Unity

which is...