archived-dots

[odd ridge]

you use systems for the script logic

[stone osprey]

Tags to implement a statemachine ? So you mean... i simply gonna mark the entity with components ?

[odd ridge]

yes

[stone osprey]

Like Entity{ ChasePlayerIfNearby } ? Well... in this case its easier than expected

[odd ridge]

yes

with a ChasePlayerIfNearbySystem with the logic

[stone osprey]

And is this the common approach ? Or are there other ones we are missing out ? ^^

[odd ridge]

it's the common approach but there is other ways too

[amber flicker]

have you seen the Unity state machine esque dots example?

https://github.com/Unity-Technologies/EntityComponentSystemSamples/tree/master/ECSSamples/Assets/Use Case Samples/1. State Machine AI

[stone osprey]

Thanks, both of you ! Im gonna look at that one ^^

I just wonder how we could keep it a bit more flexible... lets say we have two different entities, one is chasing the player in a straight line... and the other one tries to intercept the players route. Would we simply have two Entity{ ChaseWhenPlayerNearby, ChaseStraight }, Entity { ChaseWhenPlayerNearby, Intercept } and two systems which process System{ ChaseStraight, Chasing }, System{ Intercept, Chasing } ? This sounds like a lot of work for the different variatons, but i guess its the same with class based state machines

[odd ridge]

like you said, that's how a state machine works. you have to code all the possible different states yourself

[amber flicker]

you can use flag enums for increasing your permutations but... I don't much like state machines. I also think that having 'tags' as states (as with flags) you've gotta be really careful because you don't have a set of explicitly declared states. You have many permutations that are non-explicit. i.e. you define ChaseWhenPlayerNearby tag but how should this 'state' behave if there is also a FleeWhenPlayerNearby tag too - tags aren't mutually exclusive so you lose one of the main benefits of state machines imo. Caveat: I think I'm unusual in this respect - others seem to not find them so objectionable.

[safe lintel]

@stone osprey you are getting into somewhat uncharted waters for best practises and performance in the context of unity's ecs so imo experiment with what works best for you 😉

[stone osprey]

@amber flicker Well that sounds reasonable... We would need to define extra rules, which require extra components like Entity{ Chase, Flee, FleeFirst }... which sounds kinda strange.... or as you said solving this with enums like Entity{ WhenPlayerNearby{ enum : Chase, Flee }}... but both of those solutions are weird.

[odd ridge]

for the tagging, I would make sure only 1 possible of those is possible at a time. keeping it simple

[stone osprey]

That would solve the problem, otherwhise we could simply define rules like : "No fleeing when chasing cmp is attached"

But its actually pretty hard to decide between those both variants... Either a fully driven state system by tag components or some sort of state machine that relies on one component StateMachine{ enum, next, previous, ... }... the tag based state machine would require a lot of different systems, but is probably more efficient and more flexible

[amber flicker]

I don't think there are any magic answers unfortunately. Last couple of thoughts though - 1) I think that example repo is quite clean and easy to understand, 2) I'm a fan of coding what you need and nothing more. I'd try to resist the temptation to code something 'general' (esp with dod). If you know every combination of state you will need up-front, that's a different story and that's something useful to architect around.

[stone osprey]

@amber flicker Thanks for your help 🙂 Im álready looking at that repo for several minutes... reading their describtion e.g. I also heard about "Behavior trees", some sort of alternative to state machines... which also sound kinda interessting

[stone osprey]

So behaviour trees look a lot cooler than statemachines and could scale pretty well... Now i only need to figure out how to implement these into the ecs, i have read that its not a good idea to use tags in this case, because that gets "overwhelming" pretty fast

[coarse turtle]

You can take a look at this: https://github.com/quabug/EntitiesBT

you can't use Burst with it, but could give you insight on the design

otherwise stick a plain pointer to a struct and construct a Behavior Tree from those structs + put it in a component data if you want so you can run it

[red marsh]

Hello, iam new to Unity ECS System so my question, i have the following problem, ```csharp
using Unity.Entities;
using Unity.Mathematics;
using UnityEngine;

[GenerateAuthoringComponent]
public struct UnitData : IComponentData
{
public int objectId;
public float speed;
public float3 movePosition;
public int health;
public float3 attackPosition;
public Entity healthbar;

}
which is attached to a prefab gameobject, which i intantiate like thiscsharp
private void InstantiateEntity(float3 position)
{
Entity myEntity = entityManager.Instantiate(entityPrefab);
entityManager.AddComponentData(myEntity, new UnitData
{
objectId = objSeed,
attackPosition = new float3(5, 1, 5),
speed = 2,
});
// entities.Add(myEntity);

}``` now i try to find this entity by a socket.on Event to manipulate the attackPosition, but iam not sure how i can find a Entity by the ```objectId```

I would be happy if someone could help me with a tip, to make the start with ecs easier

i think it is something like csharp GetEntityQuery( typeof(UnitData) ); but how i can find the one Entity with the specific objectid

[shy pilot]

there's definitely a way to do both of those things

for the first i think you can go by the networkidcomponent

as in query for that/run a foreach

and as for the second i don't remember how but i don't remember the exact method

i have a question about burst

is it an all-or-nothing thing

so does a job/function need to be completely burst compatable to be used with burst?

[deft stump]

so does a job/function need to be completely burst compatable to be used with burst?
@shy pilot yes

it does AOT compilation each time you go back to the editor..

[shy pilot]

ah ok, thanks

[steady blaze]

hi, what is the corresponding function in Unity.Mathematics for Mathf.FloorToInt ?

[coarse turtle]

math.floor cast to int most likely - I don't remember seeing an explicit api for flooring to int

[steady blaze]

@coarse turtle ah ok, thanks. Then it should work like that: int someInt = (int)math.floor(someFloat) ?

[odd ridge]

when doing Entities.ForEach, is it possible to process 4 of them at a time instead of just 1?

[slim nebula]

is int someInt = (int)someFloat not better?

[steady blaze]

@slim nebula Not really, because if someFloat is i.e. -2.3 then (int)someFloat will return -2, but I need it to be -3

And WOW for NoiseGeneration the JobSystem ist blazing fast!!

with regular for loop for a 17x17x17 grid (17 contains the 0 of the neighbours, easier that way) and 2 octaves (simply getting the noise for coordinates 1 time with one scale and another time with other scale and then adding both values) of simplex noise, it takes 288ms to generate new noise when reloading 3x3 areas without Jobs and about 12 ms with Jobs and [BurstCompile] That's crazy! Factor 24 ‼️

😮 😲 just WOW - 😍

without burst about 76ms

[odd ridge]

yeah, regular c# is just very very slow. if you'd take that same code in c++, you'd have that kind of performance by default

[steady blaze]

@odd ridge yes, but my code for mesh creation did not speed up nearly that much. But on the other side the mesh one is regular IJob, called from each copy of the GameObject, it only speeds up about factor 2,7 (only the jobs, not setting the mesh or setting colliders)

but for the noise generation, just wow!!

[odd ridge]

nice

[coarse turtle]

@coarse turtle ah ok, thanks. Then it should work like that: int someInt = (int)math.floor(someFloat) ?
@steady blaze Just saw the msg - but yes tht's how it would work

[odd ridge]

does someone know why the Burst inspector isn't showing my ecs code?

[deft stump]

I believe burst inspector shows Assembly code

[odd ridge]

yes, I want to see the assembly code for my code

[dull copper]

from 2021.1.0a4 release notes:

* Burst: Burst enters RC phase.
* Burst: Eager-compilation is now cancelled when script compilation starts, to prevent spurious errors related to recompiled assemblies.
* Burst: Open-generic static methods are not supported by Burst, but they were previously visible in Burst InspectorBurst: they are now hidden.

I actually thought Burst was "released" long time ago (when non-preview 1.0 came out)

[odd ridge]

they are now hidden? hmm

how can I retrieve an ecs component array as a NativeArray?

[dull copper]

this was also on previous notes: md Burst: Bursted DOTS Runtime Jobs are now decorated with [NativePInvokeCallback] instead of [MonoPInvokeCallback] which could generate callback wrappers which could cause native code to inadvertently interop with the managed VM.

[zenith wyvern]

how can I retrieve an ecs component array as a NativeArray?
@odd ridge https://docs.unity3d.com/Packages/com.unity.entities@0.16/manual/ecs_entity_query.html

[deft stump]

woah waoh. RC in 2021? :wow:

[odd ridge]

thanks, I'm trying to use simd with ecs code. watching a Unity tutorial on simd says to use float4s to compute 4 at a time, but I'm confused as to how I can convert my ecs code to use float4s, because ecs code seems to work with only 1 at a time

[zenith wyvern]

I don't know a lot about it but I think the idea is you just make sure your for loops are linear and don't have branches. Burst should be able to optimize a lot just from that.

As far as I understand it at least

You shouldn't need to manually force your data into actual float4s

[amber flicker]

I think as Sark says, if you get everything "correct" burst will do auto-vectorisation for you. However, if you want the best chance I think you need to use e.g. IJobChunk where you can iterate 4 in a chunk at a time.

[odd ridge]

is there such a thing as Entities.ForChunk() ? that would be pretty handy

[amber flicker]

sadly not

it was aired on the forums - Joachim said it was among the things they were considering.. but that was like a year ago and no word of anything like it since

[odd ridge]

I see

[amber flicker]

my guess is there's a horrible amount of codegen code to support with the lambdas and doing ForChunk or something would double it - meaning they have to move a lot slower and it takes longer to maintain etc. I could imagine it surfacing in a couple of years. Writing an IJobChunk is a quick way to be reminded of how useful the lambdas are 😄

[coarse turtle]

hmm weren't they making an effort to use c# generators also 🤔

might also be why there's no word of IJobChunk lambdas

[amber flicker]

yea very likely too - I think I read that's mostly done now?

(could well be wrong)

[coarse turtle]

yea - guessing there's still no dots blog too right? 😅

i haven't been checking the forums/blogs much lately

[amber flicker]

🤣 🤣 🤣 dots blog post 🤣 🤣 🤣

[safe lintel]

😒

[dull copper]

lol

I'm currently expecting the dots blog post to land around xmas

[safe lintel]

i dont expect one this year tbh

[opaque ledge]

😭

[dull copper]

meanwhile, I still keep getting Burst compiling ~550 methods on every startup with latest dots packages + 2021.1 alpha

does it do that on older unity versions?

while it's under one minute, it's an annoyance I could do without 🙂

[safe lintel]

i dont recall it happening unless its happening without it being visible

[dull copper]

ah it does it on background task

[safe lintel]

like how it always finds something new to "import" on start

[dull copper]

it doesn't pop it up but you can see the progress bar on the bottom right in the editor and can expand it there

heh

[pulsar jay]

I am trying to use CalculateDistance in ForEach but I am getting some weird errors:
"The previously scheduled job TargetingSystem:<>c__DisplayClass_OnUpdate_LambdaJob0 reads from the Unity.Collections.NativeArray`1[Unity.Physics.CollisionFilter]"
Anybody has an idea whats the problem?

[odd ridge]

I'm trying to use an EntityCommandBuffer to add/remove components, but it's causing pretty bad stutters with huge spikes in the main thread. is there a faster way to enable/disable components?

[zenith wyvern]

You can add a bool Enabled flag to your component and check it before you process it

Or use batch operations via entity queries

[dull copper]

physics samples updated today at https://github.com/Unity-Technologies/EntityComponentSystemSamples

[odd ridge]

I want to do something like this: var type = typeof(Component); Entities.WithAll(type) but it won't let me ;p

is it possible to name a lambda so I can reuse it in many systems like I would call a function?

[rancid geode]

to reuse logic between systems, either create static methods or use IJobChunks instead

[odd ridge]

I looked at IJobChunk but there's so much code that I wished there would be an easier way

do you know of a way to disable a system from running? I want to use a system just as a base to inherit from

[steady blaze]

what makes me wonder a little:
If have the method for noise-generation of that certain index outside of the job and call it from within the job & burstcompile it is the same speed advantage and you can use Mathf there.
maybe it is a very slight difference, if you use math or Mathf, but nothing I can measure, of course mainly because it is just used for rounding one value

but yeah, it seems you can circumvent some limitations when calling methods from within a job (without losing performance)

right now the Execute is quite short ```cs
public void Execute(int index)
{
map[index] = GetVoxelValue(index, size, worldPos, scale, amplitude);
}

[odd ridge]

I want to reuse an Entities.ForEach lambda, but with different component conditions

[steady blaze]

@odd ridge sorry, did not learn to use ECS yet, only Jobs/Mathematics/Burst so far

[odd ridge]

so my issue is I have 2 systems which very much use the same code, except each system require a different component tag

duplicating the whole thing would be the easiest way, but would get tedious having to copy my changes over at 2 places everytime

[odd ridge]

IJobForEach does what I want to do but it got removed

[coarse turtle]

Why not just create a struct like so:

struct SomeJobStruct {
  // Fill your struct with data like ComponentDataFromEntity<T> and such
  public void Execute(ref T1 c1, in T2 c2) {
    // Do your lambda work here
  }
}

var jobToExecute = new SomeJobStruct { ... };

Entities.WithAll<SomeTag>().ForEach((...) => {
  jobToExecute.Execute(...);  
});

otherwise IJobChunk/static functions for reused functionality - but if the two systems kind of run similar then IJobChunk sounds like the right approach - you're just executing a different logic per chunk

[odd ridge]

yes, I wanted to avoid doing that to not having to copy paste the whole Entities.ForEach signature everytime

IJobChunk would work but it's so much more comlicated to use, lots of boilerplate

[amber flicker]

so... just to mention it... you can use GetComponent to switch logic within the foreach - yes it is a random access (per entity rather than per chunk) that you want to avoid in your hot path but it's also not 'slow'

sometimes that's worth doing while your in the early stages - then you can always optimise it later with an IJobChunk if needed

[odd ridge]

I want to duplicate a system, but 1 system has an extra tag to it

I would want to inherit the first system, and then add the extra tag on top

[amber flicker]

there is no inheritance and you can't re-use a foreach signature - but it is very easy to check for a tag within the lambda

  if(HasComponent<OtherTag>(e))
{ // do stuff }
else { // do other stuff }  
});```

[odd ridge]

any way I can do something like this? var tagType = typeof(SomeTag); Entities.WithAll(tagType).ForEach

[amber flicker]

Well you can create queries in that way and operate over them but be careful if you're going down the route of generics - a lot appears to work in editor but it actually doesn't work in a build. The rules are pretty complicated on that.

[odd ridge]

if I use queries I can't use the lambdas anymore right?

such as EntityQuery q = ...; q.ForEach(){}.Schedule();

[amber flicker]

no afaik - the one that's being generated would clash with the one you'd be passing - can't see how that would work.

Additional note - if you're not going to heed above advice of either

1. Using HasComponent in lambda
2. Separating out body to a struct or static methods
3. or just writing an IJobChunk
   Then I'd strongly recommend writing an IJobChunk and understanding what's going on. It's what things get compiled to and underlies all the magic stuff. The restrictions will also then hopefully make more sense.

[odd ridge]

do you know why IJobForEach is obsolete? there's so much boilerplate with IJobChunk if I just want to test something quick

[zenith wyvern]

do you know why IJobForEach is obsolete? there's so much boilerplate with IJobChunk if I just want to test something quick
@odd ridge https://forum.unity.com/threads/feedback-request-ijobentity.888121/

[odd ridge]

ah I see, thanks!

why is there a OnCreate() method for systems? why not just use the constructor?

[rancid geode]

probably to avoid the mistake of forgetting to call the base constructor, as there is stuff like World that needs to be populated before OnCreate

[maiden delta]

why do unity physics bodies go through each other when converting to entity with conversion mode set to "convert and inject game object"?

nvm i figured it out

nvm another related question - why do physics bodies ignore childed physics shapes when conversion mode is "convert and inject game object" but not when it's "convert and destroy"?

thing is, im trying to use hybrid ecs rn (as in, physics calculations are calculated with unity/havok physics and then transforms are copied over to gameobjects) because of me having problems with hybrid renderer. right now i have this hierarchy:

- Car (has PhysicsBody, CopyTransformToGameObjectComponent (an authoring component that adds CopyTransformToGameObject to the entity) and ConvertToEntity)
 - BodyAndCollision (has PhysicsShape and MeshRenderer)
 - WheelMesh (multiple, has MeshRenderer)
- Plane (has PhysicsBody, PhysicsShape, MeshRenderer and ConvertToEntity)

when i run the scene, the Car falls through the Plane. what am i doing wrong?

also i insist on using unity/havok physics because the raycasting there is much faster, which is essential for my game

[safe lintel]

if you use inject, nothing outside of the injected entity is converted

you will need to manually convert anything if it is a child using inject

[odd ridge]

is it recommended practice to use scriptable objects for ECS configuration data?

right now I'm using simple hardcoded data structures, but I can't edit it in the editor

[deft stump]

@odd ridge you can use SO's and then convert it to blobassets

[wet epoch]

Anyone know a good pattern for splitting code into 2 sides/teams in ECS? I have several systems that I split for optimization such as searching for enemy targets.

I've tried with Side1 and Side2 components, but because I can't use Entities.ForEach in generic functions, I end up with a lot of duplicated code.

I've also tried a Side SharedComponentData, but have run into a couple of roadblocks with that too (such as not being able to use it in a burst job, and only being able to do 1 WithSharedComponentFilter)

[rancid geode]

I did a test of it using empty Tags, but I used IJobChunks, so it was easy to not duplicate code, as I only had to create 2 similar EntityQueries

[wet epoch]

yeah, entities.ForEach just seems so much more elegant :/

but these little catches keep getting me

[odd ridge]

@wet epoch I was trying to do the same thing, right now it's impossible with Entities.ForEach

only with Job structs

[wet epoch]

ok, thanks

[red marsh]

is it possible to change the Text of a TextMesh with ECS -->

[odd ridge]

yes

[red marsh]

should i attach the entity in a convert script then?

so my problem is, idk how to access the text variable

i have this, where myEntity is the Parent Capsule --->

an i wanne change the text to the globalUnitId Variable

any ideas @odd ridge sorry for tagging, i spent 8h to find a solution without a result 😦

[maiden delta]

@safe lintel i added a converttoentity to child objects, none of them get converted according to entity debugger

ok so what i did is set conversion method of the parent to Convert And Destroy and added the CopyTransformToGameObjectComponent to all meshes and set their conversion method to Convert And Inject Game Object

and it worked

but im not sure whether thats the best method

[safe lintel]

if you have inject on a parent, child with inject wont work, you need to do it manually

[odd ridge]

@red marsh TextMesh is not an ECS structure so you cannot access it from inside your jobs. this is how you access it EntityQuery query = GetEntityQuery(new ComponentType[] { typeof(TextMesh) }); NativeArray<Entity> entities = query.ToEntityArray(Allocator.TempJob); int i = 0; foreach (Entity entity in entities) { var textMesh = EntityManager.GetComponentObject<TextMesh>(entity); textMesh.text = i.ToString(); i++; } entities.Dispose();

[safe lintel]

you can just use ForEach

Entities.ForEach((Entity entity, TextMesh textMesh)=> { 
textMesh.text = "potato";
}).Run();

[zenith wyvern]

You'd need WithoutBurst though

[red marsh]

thank you very much, i will test it in view minutes

[odd ridge]

oh yeah that's much better

as long as you are not using generic system types, that will work

[maiden delta]

how do i add arrays to components?

i think it's using dynamicbuffers, but explanation online is a bit confusing

[zenith wyvern]

We're not going to be able to explain it better than https://docs.unity3d.com/Packages/com.unity.entities@0.16/manual/dynamic_buffers.html

If there's something specific about that page you don't understand we can help

[maiden delta]

so, i create a new component that inherits IBufferElementData and that will be like, a separate component on entities?

[zenith wyvern]

Yeah, it's acts exactly like IComponentData except you access it a little differently

[maiden delta]

so i have this

using System;
using Unity.Collections;
using Unity.Entities;
using Unity.Mathematics;

[Serializable]
[GenerateAuthoringComponent]
public struct CarAxle : IBufferElementData
{
    public int wheels;
}

it only lets me assign integers. how do i create a buffer that references entities?

[zenith wyvern]

Change int to an Entity

[maiden delta]

it no longer generates an authoring component with a list inside. is the only way to fix this write an authoring component myself?

[zenith wyvern]

Yes, you'd have to have a gameobject authoring component with a list of your gameobjects, then add their converted entities to your buffer during your CarAxle conversion

It's a bit complicated too. You have to make sure your wheel gameobjects get converted first, then access their entity with conversionSystem.GetPrimaryEntity

But as long as your wheel gameobjects are children of your CarAxle they will be converted first

Although now that I think about it if they are already child gameobjects then Unity will automatically generate the Parent components and Child buffer. So your wheels will be in the Child buffer on your CarAxle, assuming you're converting it in the normal way

[maiden delta]

hm, might as well just get the children of an object instead of using an array yeah

how do i access children with a ForEach? in Child[] children? because Child only has one entity in a value

oh nvm burst hinted me a bit

[vocal talon]

Good morning everyone.
I'm trying to wrap my head around DOTS.
Need to find a good entry point. Should I go with the Project Tiny samples?

My end goal is a rather complicated RTS. So, asking if Tiny is a good learning stepping stone, or would I be constrained to those web and mobile projects?

[olive kite]

@vocal talon I would suggest the ecs samples first and then the physics samples.

Does anyone know how Visual Effects graph conversion works into dots? I see a heavy update coming from it when converting it. Is it using cpu if converted?

I suppose that would make sense if it is updating it in jobs and such.

[spiral stirrup]

@vocal talon If you're looking for something more guided after reading the docs, i've been doing this tutorial and i recommend it:
https://www.udemy.com/course/unitydotsfundamentals/

[deft stump]

Does anyone know how Visual Effects graph conversion works into dots? I see a heavy update coming from it when converting it. Is it using cpu if converted?
@olive kite currently there's no conversion of vsgraph. you're probably looking at a hybrid-ed entity there, which imo, is quite heavy.

[olive kite]

@deft stump oh okay, dang. good to know. For the HDRP features then it has a list of features for V2, so that just means it can hybrid them?

well i guess it's still the same renderer right, just not in gameobject hierarchy form

[wet epoch]

yeh i think it might be converted with hybrid renderer v2

(you need to add the preprocessor command to your project settings to enable it)

[foggy stream]

quick question, ping me for answers. I need Vector3.RotateTowards math equivalent

[zenith wyvern]

@foggy stream You can copy https://github.com/jamesjlinden/unity-decompiled/blob/master/UnityEngine/UnityEngine/Quaternion.cs#L354

Just remember the new math library uses radians instead of degrees

[foggy stream]

@zenith wyvern Oh, I meant the Vector3 RotateTowards. I can't find it here... https://github.com/jamesjlinden/unity-decompiled/blob/master/UnityEngine/UnityEngine/Vector3.cs#L371

[zenith wyvern]

Oh sorry, my mistake

[maiden delta]

i know it isn't really a dots question, but is there any alternative to Mathf.Approximately in Unity.Mathematics?

[dull copper]

I dunno if there is but you could roll a better on on your own

I'm assuming it does something like the snippet here: https://docs.unity3d.com/ScriptReference/Mathf.Epsilon.html

@maiden delta

[vocal talon]

@vocal talon If you're looking for something more guided after reading the docs, i've been doing this tutorial and i recommend it:
https://www.udemy.com/course/unitydotsfundamentals/
@spiral stirrup Yeah. I actually bought this just prior to asking

[stone osprey]

Lets say theres a way to serialize single entities at some point... would you rather use a sql or nosql database for storing entities in a large amount ?

[deft stump]

sql, I guess

since ECS is structured alot like SQL database

[stone osprey]

@deft stump Thanks ! Well thats true... im just not that sure about the component count... lets say each component is its own table and we have one table that stores the entity itself, that would require a join if we would want to select that entity. Too many joins do have a bad performance, furthermore theres a join limit of 64 in mysql :p

[deft stump]

@stone osprey chunk = table

Entity as a primary index

and the rest are coloumns of components

[stone osprey]

@deft stump Well... i thought following tables : Entity{ id, index, version} Position{ id, x,y,z} and then if we wanna load entity with the id 5 for example we would need to join those : select * from entity inner join position where id = 5

[deft stump]

@stone osprey well that's a lot of joins. my idea is just getting around that giant headache

biggest reason why I quit being the database guy

[stone osprey]

@deft stump Yes it is, thats because i have been looking for better solutions recently :/ So you would favor one big table ? Atleast it looks like you would have one table with position, rotation, scale embedded ^^ That would work great for transform stuff, but what if you had a player component ? A weapon component ? Ai components e.g. all of them wouldnt fit into one table

I actually dont like databases... i always have too much trouble with them. My server uses an ecs with hibernate and currently im struggling with multithreading the update operations

[junior fjord]

Can I somehow use Unity to write the backend and do the frontend mainly in html5? I know I can compile to webGL but I mean write some of the html/js frontendstuff myself? I mainly want to use the unity ecs with its multicore support as backend and do the frontend myself, since the game will be mostly simulation (heavy) in backend, and menus and light 2d in frontend

[amber flicker]

putting aside how unpleasant that sounds to me 😅 ... pretty sure webgl support doesn't include multi-threading? perhaps that's changed.

[lean raptor]

Are Unity Jobs runned preemptive? I mean, can a Unity Job be suspended in the middle of execution so another job take its place (or the main thread continue execution, for example, if in WebGL)?

[amber flicker]

pre-emptive? Jobs launch from the main thread when you call e.g. Schedule. You can't suspend them or something like that afaik. Not sure how that's relevant to webgl either.

[deft stump]

When you call Schedule, a job gets queued. It will run whenever it wants to do it.

[lean raptor]

WebGL is single threaded, so all Unity Jobs actually run in the same thread. That is why I ask if they are preemptive. Otherwise a 3 second Unity Job will freeze the UI for that duration in WebGL

[deft stump]

Also you can;t suspend a job in the middle of its run. It has to complete otherwise you're gonna get some lovely mem leaks with those native containers hanging around

[lean raptor]

I'm actually using managed objects inside unity jobs 😉. It's not the best practice but it works XD

[deft stump]

how? :0

[lean raptor]

how? :0
@deft stump

struct Example : IJob
{
  private GCHandle a_;
  public Example(string a) => a_ = GCHandle.Alloc(a, GCHandleOption.Pinned);
  public void Execute()
  {
    string a = (string)a_.Target;
    // If you don't use the Burst Compiler you can do whatever you wanat!
    string b = new string('q', 5); // allocate managed objects!!! (warning: super slow)
    a_.Free();
  }
}

[deft stump]

oooooh.
if it's slow then I don't want to do it XD

[lean raptor]

You don't need to allocate objects inside the Unity Job

[deft stump]

I mean... I could use C# async

[lean raptor]

They can be allocated before!

A lot of algorithms doesn't require allocation actually

Even more, you can use lock()s inside Unity Jobs

[red marsh]

Hello, i have a problem, i try to to lock the rotation of healthbar that it always is in one direction but it doesnt work--->

i try to set a float4x4 to 0 but doesnt work

does someone have a solution for that

[rancid geode]

LocalToWorld is set in TransformSystemGroup when you have Position and/or Rotation component (or any other of the Tramsform-related components)
What you want is to either:

A. Set the Position and Rotation component values before TransformSystemGroup runs
B. Only if you really know what you are doing: remove position and rotation component and set the LocalToWorld matrix manually

[red marsh]

@rancid geode problem is, the healthbar should always Rotate to the direction of camera like i did it in mono unity, but idk how i can handle this in ecs with the child object

I mean i can store the Rotation of the parent in the struct of the child then i can transform from local to World Rotation, but i hope there is a cleaner and easier solution

Or does someone have a good example to rotate the healthbar in direction of camere in ecs

[lean raptor]

How can I pass a managed object reference to a Unity Job in WebGL? (I'm not using the Burst Compiler, so I can do managed stuff inside jobs)
Normally, I would use a GCHandle or IntPtr to store the reference of the object, but in WebGL build this doesn't work (I get "ArgumentExcection: Object contains non-primitive or non-blittable data.")

[shy pilot]

if it's erroring because its not blittable that means you can't use managed stuff @lean raptor that would be my guess

that or its a bug

does anyone know if it's possible to add to a nativelist from an ijobparallelfor

[frigid quarry]

Hi guys,I'm working on a new RPG project, need a really strong pathfinding system. wander dots or compute shader, which one will make the best use of GPU

[shy pilot]

@frigid quarry dots is cpu only just like monobehaviours, the difference is the performance boost granted by jobs and burst

if you really want to use the gpu

then you'll have to use a compute shader

but that's definitely not the purpose of a compute shader so i wouldn't reccomend that

so dots is the best choice overall

i'm pretty sure you can use the unity navmesh from jobs as well

there are definitely repositories for pathfinding in dots

i saw one that could handle i think 50,000 concurrent entities

using the traditional navmesh system for calculations

[frigid quarry]

I saw burst will use gpu in some tutorials

[shy pilot]

hmm

[frigid quarry]

not sure but saw it somewhere

[shy pilot]

i'm not aware of that

the primary concept of dots is to use the whole cpu instead of just one thread

i'll check though

[frigid quarry]

yeah, but dots code can be used by gpu as well

[shy pilot]

i don't think so

the selling point of dots is multithreading

so doing stuff in parallel

but on the cpu not the gpu

i'm not 100% sure it's just that this is the first i've heard of dots on the gpu

[frigid quarry]

https://forum.unity.com/threads/theoretical-sending-jobs-to-the-gpu.850807/

[shy pilot]

hmm

that entire conversation (as far as i can tell) is about shaders

the purpose of a shader is for rendering behaviour not things like pathfinding and actual "game-code"

[frigid quarry]

ok, my mistake

[shy pilot]

and since dots is already difficult to use i can imagine adding the extra complexity of using gpu VRAM to store information would be incredibly annoying 😆

[frigid quarry]

by the way, gpu is able to pathfinding,https://www.youtube.com/watch?v=1OSXWhd3hvI&t=1s

[shy pilot]

oh, i wasn't aware that was possible 😆

[frigid quarry]

with a hugh number of agents, gpu may works better

[shy pilot]

oh it definitely would

but dots can already handle tens even hundreds of thousands of entities

[frigid quarry]

so before I start work ,wanna know which one will do better ,dots or compute shader

[shy pilot]

if you can get it to work somehow a compute shader might be better

my only concern is that to calculate paths you'd need to copy a lot of information from ram to vram

and that is a famously slow and inefficient process

(the same reason the vfx graph can barely interact with the physics engine at all)

[frigid quarry]

My game is not a fancy AAA graphic game, there should be a lot room for GPU,but dots on the other way if can achieve same amount of GPU can do,will same me alot time fight with compute shader

[shy pilot]

yeah

if i were you i'd go with dots

but

are you making an mmorpg or an rpg?

[frigid quarry]

RPG with multiplayer no more than 16

[shy pilot]

hmm

well, you may encounter a problem there

[frigid quarry]

everything is calculated on the host machine

[shy pilot]

yeah

this sounds like a very difficult project 😅

dots netcode is designed for first person games

so its not optimised for this kind of application

so you may encounter some friction there

[frigid quarry]

i konw , but the host only have to steam result to clients,will not be alot npc on screen

they just do some dirty work off screen

[shy pilot]

yep

as long as the world is fairly small it should be ok

you may need to write your own netcode though using the transport layer manually

cause this really isn't what unity's netcode is built for

[frigid quarry]

I'm trying to make a world every npc acts like Really living in there

[shy pilot]

yeah

[frigid quarry]

so those things don;t have to give to client until client get to the place

[shy pilot]

yep, area of interest/selective data streaming is going to be super important

but i don't think netcode has anything built in to do that

since its designed for fps games on fairly small maps

my main advice is to be careful cause these kinds of games are very very difficult to make

mmorpgs usually have teams of 200 to 300 developers

[frigid quarry]

I'm mainly using dots for calculation and the network I'm about to use mirror

[shy pilot]

even with a small game this is a lot of work

so you should definitely make sure you're ok with that before starting

[frigid quarry]

Yes, picking the tool is very important

[shy pilot]

not so much the tool but the project

while MMO games have been made with small dev teams

you'd have a lot of work to do

it's definitely a big commitment

[frigid quarry]

well, that is me personal problem isn't it

[shy pilot]

yeah

so ultimately its up to you, just want to make sure you know what you're getting into 😆

[frigid quarry]

not the first time, I can say that

[shy pilot]

this stackexchange post has some examples of mmo games made by small teams

https://gamedev.stackexchange.com/questions/90/why-is-it-so-expensive-to-develop-an-mmo/630#630

[frigid quarry]

that is a multiplayer game but not mmo really, like terraria

maybe you get it wrong

[shy pilot]

yeah i understand that you want a small multiplayer game (lan and such)

so one person hosts and their game does all the server calculations

[frigid quarry]

yes,and most time people can just play alone

[shy pilot]

so it won't be as hard as any of those things

basically what i'd reccomend doing is starting small

and then expanding up to what you want your end result to look like

you could definitely do it

it'll be hard but its definitely possible

either way, good luck and i hope the project goes well 😄

[frigid quarry]

Thanks, but I still need an answer about dots and compute shader which one will be better on path finding

so far the showcases I found on youtube both result about 2000-3000 agents

[shy pilot]

well in that case

go with dots

https://github.com/zulfajuniadi/unity-ecs-navmesh

this implimentation can supposedly reach 100,000

[frigid quarry]

on good, that is a kill

[shy pilot]

using unity's built in navmesh

with 40-50 fps

but it will be less than that for you since your game won't just be a bunch of things moving around 😆

[frigid quarry]

Yes, that will do

[shy pilot]

hmm

only concern with that is that it doesn't work for the latest ecs

so you may need to manually update it

[frigid quarry]

that is already a lot easier

[shy pilot]

ok, good luck :)

[frigid quarry]

👍

[deft stump]

@dull copper sorry for ping but curious if youre getting this error.

UnityEngine.StackTraceUtility:ExtractStackTrace ()```
with subscenes

in 2021.1.0a4

[dull copper]

Cant remember

[lean raptor]

if it's erroring because its not blittable that means you can't use managed stuff @lean raptor that would be my guess
@shy pilot It's possible to use managed code in Unity Jobs. But it's not possible for a struct which imeplements IJob have managed fields, so it's quite difficult to move managed code to a job

[craggy stag]

Hi people,

im working on a wavespawner system for Dots which should allow to assign wavestypes/settings and the relevant enemyprefab in the inspector.
-arrays/lists in IComponentData lead me to the neither primitive nor blittable issue
-a wavesettings IComponentData script on converted Gameobjects in hierarchy leads to non-nullable issue when entity querying them into native array

I'm somewhat at a loss as to how to approach this.
Any help/tips would be much appreciated.
Thank you.

[zenith wyvern]

For associating a list with an entity you should use a dynamic buffer

As for the rest you'll need to be more specific - show what you tried and the error you're getting

[craggy stag]

Ok thank you i'll give the Dynamic buffer a try and post a more specific issue statement if the issue persists!

[shy pilot]

@lean raptor i'd reccomend just doing what i've been doing and only use managed code in systems then put as much of the logic as you can in a burst job

as in have the non burst compatible code in its own job that updates afterwards

it's not always possible to do this and i don't know exactly what you're trying to do but it works for me :)

[proper silo]

Hello! Is there a way to tell a system to not update if there is no Entities usable in the Entities.ForEach present in the system? I have a system with nativearray allocation and dispose outside of ForEach, so it does it every frame for nothing if there is no corresponding entities

[hollow sorrel]

@proper silo should already be happening automatically

is it not for you?

[proper silo]

No, the system runs, but I am also doing some SystemBase.GetSingleton in the OnUpdate, which might mess things up

Good to know that it is supposed to be automatic tho, will try to find out what happens in my code, thanks !

[hollow sorrel]

hmm

it could be the singleton yeah, not sure how to get around that

[proper silo]

Yep it is the singleton, just tested it: removing the call mark the system as "not run" in the entity debugger !

[hollow sorrel]

also for full explanation, normally you use RequireForUpdate(entityquery) to make a system only update when there are entities matching, but Entities.ForEach adds it automatically with unity's codegen

ah

[proper silo]

Ohhhhhh thats intresting, thank you!

[amber flicker]

https://forum.unity.com/threads/ilpostprocessing-slow.913814/#post-6500213 - code gen speed-ups expected in 0.17

[proper silo]

@hollow sorrel Actually, calling RequireForUpdate(entityquery) at the start of the update before the singleton stuff make it so that the system is not run if the query is empty!

[hollow sorrel]

oh nice, maybe codegen doesn't add it automatically then

[proper silo]

Seems to be a problem though, as when I put the following code at the start of my OnUpdate, the time it take for my System to run if the Query find something increase little by little every frame, like it starts at ~0.04ms and after ~20 second of running reach ~0.40ms

generateTagQuery = GetEntityQuery(typeof(GenerateMapTag)); RequireForUpdate(generateTagQuery);

[hollow sorrel]

oh yeah

you don't want to put that in onupdate

use https://docs.unity3d.com/Packages/com.unity.entities@0.16/manual/ecs_entities_foreach.html#accessing-the-entityquery-object to store the entityquery and then do requireforupdate once on start

can use getentityquery instead of that foreach way too but should still do that on start

[proper silo]

ohhhh its on start ! Thanks !

[deft stump]

how many components is too much components?

coz each time I approach a problem, it always comes down to adding a new component for better caching

[spark glade]

Is anyone using 2020.1.* to build for Android? I have 100% official bug with a trivial repo scenario and it doesn't seem to have been fixed in 2.5 months.

https://fogbugz.unity3d.com/default.asp?1273917_bmoc1968lnp7kc3c

So if anyone uses com.unity.platforms.android, which should be anyone building dots for Android on 2020.1 or later, please let me know ❤️

[spark glade]

Ohh gawd... I figured it out: https://forum.unity.com/threads/2020-1-3f1-il2cpp-build-error.959796/#post-6501657

[olive kite]

how many components is too much components?
@deft stump For efficiency I think that is intentional, so each system only works on the minimum amount of data. But I think there is a limit for how many components you can use for .foreach iterations, not sure if there is a way to do it on an array of components.
But yeah, I feel I am doing the same

[fluid kiln]

I just upgraded to the entities 0.16 version. Can you not use EntityCommandBuffer in a SystemBase anymore?

EntityCommandBuffer was recorded in ConnectedServerSystem and played back in Unity.Entities.BeginInitializationEntityCommandBufferSystem.

The previously scheduled job ConnectedServerSystem:<>c__DisplayClass_OnUpdate_LambdaJob0 writes to the Unity.Entities.EntityCommandBuffer <>c__DisplayClass_OnUpdate_LambdaJob0.JobData.ecb. You must call JobHandle.Complete() on the job ConnectedServerSystem:<>c__DisplayClass_OnUpdate_LambdaJob0, before you can write to the Unity.Entities.EntityCommandBuffer safely.

[north bay]

Looks like you did forget to pass the ConnectServerSystem Dependency/Jobhandle to the BeginInitializationEntityCommandBufferSystem by calling AddJobHandleForProducer on it.

[fluid kiln]

I'm not sure how old my Entities version was but I haven't had to deal with dependencies and job handles so far. I would just use Entities.ForEach inside OnUpdate

So in my OnCreate of my ConnectServerSystem I have to call AddJobHandleForProducer on the BeginInitializationEntityCommandBufferSystem?

[north bay]

No after you schedule your Entities.ForEach. The structure of your OnUpdate should look like this:

            var commandBuffer = m_barrier.CreateCommandBuffer();
            
            Entities.ForEach( ( Entity ent ) => { commandBuffer.AddComponent<Whatever>(ent);} ).Schedule( );
            
            m_barrier.AddJobHandleForProducer( Dependency );

[fluid kiln]

What is m_barrier in your case? I would create the ECB from EntityCommandBufferSystem

[north bay]

Yea the barrier is just the EntityCommandBufferSystem

[fluid kiln]

Cool thank you very much!

[north bay]

No problem 🙂

[lean raptor]

Does Unity Jobs run immediately when you execute job.Schedule() in WebGL platform or they are queue as in other platforms? I though the second one, but I did some tests and it seems to do the first option.

[fluid kiln]

Why could I be getting not disposed exceptions on a persistent native list?

[deft stump]

in editor?

[safe lintel]

what does your code look like? maybe you are creating them more than once?

[deft stump]

or maybe you didn't dipose them? in editor persistent containers has a timer when throw to exception. note they're already leaking

[dusty sleet]

Hi, where is this CONVENTIONS.md? can't find it

[dull copper]

you can't find it because it's not there

I have a feeling that's some internal file they use as guideline that accidentally got marked on the public changelog

for another example, I don't think we have gotten the HDRP / URP hybrid renderer v2 samples which docs tell to be there

[dusty sleet]

😂 thanks

[spark glade]

Good Lord, finally got animations running in Android 🙌🙌🙌

2020.1 + (essentially) alpha packages + mobile builds.... I must hate myself 😅

🥳🥳🥳

[safe lintel]

I’ve got questions(after I drink some coffee)!

[safe lintel]

@spark glade are you switching animations at all? do you rebuild your graph when you do so? or is it through dfg nodes(and if so did you make a custom dfg node?)

[fluid kiln]

what does your code look like? maybe you are creating them more than once?
@safe lintel @deft stump It's in the OnCreate of a system. But I'll try to dispose of it in the OnDestroy

I can't seem to find the DOTS equivalent of Camera.ScreenToWorldPoint() with an entity camera. Is there yet a way?

[radiant sentinel]

hello, how can i convert byte array to FixedListBytes64?

its not a good way :/

[zenith wyvern]

I can't seem to find the DOTS equivalent of Camera.ScreenToWorldPoint() with an entity camera. Is there yet a way?
@fluid kiln

var cam = EntityManager.GetComponentObject<Camera>(cameraEntity);
cam.ScreenToWorldPoint()

[fluid kiln]

Well now that seems obvious 😂

[odd ridge]

is there a way to trigger an update of systems immediately at game start instead of at the end of the timestep?

since I put my systems in FixedStepSimulationSystemGroup, when I click play, I can see my entities are not ready when I start the game for a very short moment because the first timestep hasn't been reached yet

I would need an attribute to my system like [UpdateOnStart] that would do an initial update of the system when starting instead of waiting for the timestep

alternatively, is there a way to change the update sequence such that system updates happen at the beginning of a timestep instead of at the end of the timestep

[coarse turtle]

Get all the systems in FixedStepSimulationSystemGroup and call Update() on the start of the game?

[radiant sentinel]

hello, how can i convert byte array to FixedListBytes64?
@radiant sentinel
Guys can you help me ? please

[zenith wyvern]

I don't see anything wrong with the code you posted. Why do you think it's so bad?

Aside from it being a foreach. If you use a normal for loop and run it in burst it will be pretty dang fast.

[zenith wyvern]

@radiant sentinel

    unsafe
    {
        fixed (byte* ptr = &arr[0])
        {
            fixedBytes.AddRange(ptr, arr.Length);
        }
    }

[spark glade]

@spark glade are you switching animations at all? do you rebuild your graph when you do so? or is it through dfg nodes(and if so did you make a custom dfg node?)
@safe lintel literally one fixed animation for now. Upgrading to 2020.1 for android was a real pain. Currently can't even build an AAB, just a APK. If it turns out to be stable, I'll happily release it. Anything is better than T poses, hahaha

[safe lintel]

ah, ok

[lean raptor]

Two unrelated questions.

1. How can I check if some code is running inside a Unity Job thread.?
2. Is there any way, even if obscured, to jump from the Unity Job thread to the main one for a while?

[rancid geode]

Two unrelated questions.

1. How can I check if some code is running inside a Unity Job thread.?
2. Is there any way, even if obscured, to jump from the Unity Job thread to the main one for a while?
   @lean raptor

1. JobsUtility.IsExecutingJob https://docs.unity3d.com/ScriptReference/Unity.Jobs.LowLevel.Unsafe.JobsUtility.IsExecutingJob.html
2. AFAIK no, the "recommended approach" (I personally don't recommend that lol) is to create a coroutine that waits for the job to be complete, then execute the stuff needed and then schedule a new job. My recommendation here is to avoid coroutines all together and use UniTask instead, the overall logic would be the same, but coroutine is an issue by itself 👀

[lean raptor]

Ok thanks @rancid geode

[shy pilot]

I'm currently trying to update some outdated scripts from a public repository

but some of this is so old that i have no idea what it means

what is the meaning of [Inject]

[shy pilot]

i'm trying to adapt https://github.com/zulfajuniadi/unity-ecs-navmesh to the latest version of entities

[odd ridge]

@coarse turtle I'm calling World.GetOrCreateSystem<FixedStepSimulationSystemGroup>().Update(); in my system's OnStartRunning() yet I'm still seeing a delay before the first update happens. what am I doing wrong

[coarse turtle]

maybe you need to use World.PushTime(...) or a similar API since it's probably still doing the time checks

can't remember what the exact API was but you can probably just overwrite the time initially so that FixedStep runs initially

I mainly push Time in my own tests just to check some conditions if I'm too lazy to playtest whether some time stamping thing works

[elfin river]

Is dots performate enough to maybe do something like minecraft but with the objects instead of mesh generation

I'd say not but it would be interesting if it could do something like that (obviously you'd still have chunk loading)

[odd ridge]

@coarse turtle I tried World.PushTime(300,300); but my systems still have a delay before the first update 🤔

I call it in the OnCreate() function of my SystemGroup which is inheriting from FixedStepSimulationSystemGroup

[gusty comet]

i'm trying to convert gameobjects to entities

FromWorld returns a GameObjectConversionSettings with EntityManager set to null

so i can't use it?

any ideas

or better solutions, i'm new to DOTS

[coarse turtle]

@odd ridge hmm sorry I'd need to look into the source to see how update works.

[shy pilot]

what is the equivalent of [Inject] in the current ecs version

[safe lintel]

making an entityquery @shy pilot

[shy pilot]

ok thanks

does anyone have a version of this

https://github.com/zulfajuniadi/unity-ecs-navmesh

that works for the latest entities

i'm a bit pressed for time so if someone else has already done this i'd really appreciate it

[rancid geode]

@shy pilot did you try https://github.com/reeseschultz/ReeseUnityDemos ?

[shy pilot]

that is out of date a couple of versions too to my knowledge

it is newer though so i might try that

[shy pilot]

oh wait nevermind i didn't notice the separate branch

looks good to me

time to figure out how to use it

@rancid geode do you have any experience with this package?

[rancid geode]

@shy pilot tried once, but didn't actually used it in the end

[wary anchor]

Do you guys use the new Input System? I've not been able to get it to work in my DOTS project since i first tried it around a year ago (and last tried it today). Wondering if it's a specific package conflict or something 😦

[lean raptor]

Odd question, I found a way of how to jump to the main thread from an Unity Job, but I don't know how to jump it back to the thread job. Any idea?
With this code you can jump to the main thread.

public struct ThreadSwitcherUnity
{
    public static SynchronizationContext UnitySynchronizationContext { get; private set; }
    
#if UNITY_EDITOR
    [InitializeOnLoadMethod]
#endif
    [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.BeforeSceneLoad)]
    private static void Initialize() => UnitySynchronizationContext = SynchronizationContext.Current;  

    public ThreadSwitcherUnity GetAwaiter() => this;

    public bool IsCompleted => SynchronizationContext.Current == UnitySynchronizationContext;

    public void GetResult() { }

    public void OnCompleted(Action continuation)
    {
        if (continuation == null)
            throw new ArgumentNullException(nameof(continuation));

        UnitySynchronizationContext.Post(_ => continuation(), null);
    }

    IThreadSwitcher IThreadSwitcher.GetAwaiter() => this;
}

[rancid geode]

No idea, but be aware that this won't work with Burst

[zenith wyvern]

Do you guys use the new Input System? I've not been able to get it to work in my DOTS project since i first tried it around a year ago (and last tried it today). Wondering if it's a specific package conflict or something 😦
@wary anchor I do and it works great. What part isn't working for you?

Make sure you have it enabled in project settings. It still defaults to "Old input system only"

[wary anchor]

@zenith wyvern I posted over in #🖱️┃input-system with lots of details. I wonder which package it is that's conflicting?

[zenith wyvern]

Not sure what could be causing that, it doesn't look dots related though

There is another version available from the package manager, maybe try that

You have to pick it manually

[wary anchor]

It's been this way for almost a year now across all the various different packages from both dots and input system and several different unity versions

[zenith wyvern]

You're saying it works without dots?

[wary anchor]

In a completely empty new project, I install and set up new input and it'll give me that console error I posted in the last message I wrote, but the input system package window is populated in that case

So it seems to be 2 separate errors, with dots it's completely nonfunctional

[zenith wyvern]

No idea what could be doing it. I would open a bug report and post it on the input system forums

[wary anchor]

Maybe this time it won't be ignored like it was when I posted several months ago 🤷 Cheers Sark!

[odd ridge]

@lean raptor by curiosity, why would you try to jump back to main thread from within a job thread?

and did anyone succeed at triggering system updates right at the start instead of waiting for the timestep? I put my systems in fixed step group and I can see my entities suddenly jump at the start because it's waiting for the first timestep to do a first update. I tried many things and I can't get it to work. for example, I set the world time to 300 seconds so that it's immediatly above the timestep at the start for it to immediately do a system update World.DefaultGameObjectInjectionWorld.PushTime(new Unity.Core.TimeData(300, 300));, but it doesn't work. system doesn't update until timestep

I called Update() on my system and group in the OnStartRunning() function so that as soon as the game start, it does an initial update. doesn't work either

[lean raptor]

@lean raptor by curiosity, why would you try to jump back to main thread from within a job thread?
@odd ridge It's useful to perfom task that can only be done in the main thread, such as spawn a gameobject, or perform a raycast.
I know that the best practice would be splitting the Unity Job in two and to Job -> Main Thread -> Another Job, but...

[untold night]

@lean raptor - have you looked at async-await support in Unity? It supports launching tasks and awaiting them on the main thread, via a similar method to coroutines.

[shy pilot]

how do you access the iterator in a scheduleparallel

with foreach syntatic sugar

for parallel buffer purposes

follow up question:

i have a design plan but i'm not sure how dots friendly it is

each entity in my game has a state, searching for food, searching for a mate etc

and i need a component to hold that data

so my plan was to make an interface that extends icomponentdata and then use that to make a component for each state value (so i can filter it in a foreach)

would it be better to just use one component type and store an enum in there and just filter with an if statement?

i tried implimenting the former:

public static void SetState(Entity creature, StateComponentBase stateComponent, EntityCommandBuffer buffer)
 {
    //Clear the state
    buffer.RemoveComponent(creature, typeof(StateComponentBase));
    //Set the new state
    buffer.AddComponent(creature, stateComponent);
 }

public static void SetState(int iterator, Entity creature, StateComponentBase stateComponent, EntityCommandBuffer.ParallelWriter buffer)
{
    //Clear the state
    buffer.RemoveComponent<StateComponentBase>(iterator, creature);
    //Set the new state
    buffer.AddComponent(iterator, creature, stateComponent.GetType());
    buffer.SetComponent(iterator, creature, stateComponent);
}

but for some reason using an instance of StateComponentBase isn't acceptable when using a parallel command buffer

[hollow sorrel]

@shy pilot i dont think you should use inheritance inheritance for this, but is your statecomponentbase a struct?
also, wouldnt your code still be the same there if it was just using icomponentdata

[shy pilot]

that is a good point actually

i'll change it to that and see if anything changes

i just don't understand why it compiles with a standard buffer and not a parallel one

[hollow sorrel]

not sure

[shy pilot]

oh wait, i remember why i had statecomponentbase now

because to filter the entities properly i need to remove the existing state component from the entity

and if i removed statecomponentbase i'd end up removing all the components from my entity :/

[zenith wyvern]

Why not have a separate component for each state?

What's the point of it being an enum?

[shy pilot]

not sure what you mean there

ohhh

[zenith wyvern]

struct FindingFood : IComponentData struct DoingWhatever : IComponentData

Etc

Then you can filter directly by state

[shy pilot]

because isn't it more efficient to use that to filter them instead of looping through all of them (especially if using scheduleparallel)

since then it would be making jobs that just return immediately etc

also some states require extra data that wouldn't be needed for others so this made more sense

[zenith wyvern]

I'm not sure what you mean, more efficient how?

[shy pilot]

i can imagine that scheduling jobs unecissarily isn't good practice?

[zenith wyvern]

Can you give an example of how separate components would cause you to schedule a job unnecessarily?

[shy pilot]

separate components isn't the problem

that's the ideal solution, it just doesn't work with a parallel buffer for some reason

[zenith wyvern]

Can you elaborate on that? What doesn't work?

[shy pilot]

that compiles just fine

which would be the non parallel implimentation

but that does not

p.s the add component and set component are separate cause i ran into the same problem with addcomponent

i get the message

[zenith wyvern]

I'm still confused about what you need this statecomponent base for. It sounds like you're trying to do OOP

[shy pilot]

yeah, i guess this is fairly oop-ish

but it also feels oop-ish to put all states in one component

since there would be unused variables depending on the state

[zenith wyvern]

...again, why can't they be separate components?

[shy pilot]

oh, you mean like unrelated?

[zenith wyvern]

Yes. Like each one is it's own IComponentData.

[hollow sorrel]

@shy pilot can you show statecomponentbase

[zenith wyvern]

That has nothing to do with the others.

That's how ECS is supposed to work. Then you can filter on each component as needed

[shy pilot]

@hollow sorrel it's just an empty interface

i was trying to do it that way because having to run removecomponent on each state type seemed inefficient as well

[zenith wyvern]

Well I don't know how you're using these things exactly but if you want to avoid state change performance hits I would say go for ECB first, then an event system if that's still too slow

[shy pilot]

entity command buffer?

the state is re-evaluated every frame for every entity so i was trying to keep optimisation in mind when i wrote that code

[zenith wyvern]

Ahh okay, then yeah that's a lot of structural changes. You could look at Unity's state machine example they made

I don't remember how they did it

[shy pilot]

ok, thanks i'll have a look

[zenith wyvern]

https://github.com/Unity-Technologies/EntityComponentSystemSamples/tree/master/ECSSamples/Assets/Use Case Samples/1. State Machine AI

[shy pilot]

thanks

hmm, they seem to have two functions for each state, one to transition to (adding components) and others to transition from(removing components)

as opposed to one state change method

[zenith wyvern]

Yeah I was just glancing at the readme. They actually go in depth about the performance trade-offs they considered based on their requirements. They suggest some alternatives too

[shy pilot]

yeah, thanks for putting me onto this 😆

[lean raptor]

@lean raptor - have you looked at async-await support in Unity? It supports launching tasks and awaiting them on the main thread, via a similar method to coroutines.
@untold night Oh, didn't know that. I'll give a check

[cerulean wren]

Hi!
Anyone had problems with similar error?

(0,0): Burst error BC1060: An entry point function `BurstClass.BurstTest(ref BurstClass cls)` cannot be called internally

It's simple call like:

[BurstCompile]
public struct BurstUse
{
    public int Int;

    [BurstCompile]
    public static void Use(ref BurstUse use)
    {
        BurstClass.BurstTest(out var test); // Causing the issue
    }
    //  ...
}

[BurstCompile]
public struct BurstClass
{
    // ...
    [BurstCompile]
    public static void BurstTest(out BurstClass cls)
    {
        cls = new BurstClass
        {
            Int = 0
        };
    }
    // ...
}

Got a repro, so I'll report it if I'm not doing anything dumb. (using Burst 1.3.9 same thing on 1.3.7)

IMO it looks like burst is trying to inline the BurstTest function but also call it...?

[hollow sorrel]

@cerulean wren i could be wrong, but i don't think what you're doing is supported by burst

[cerulean wren]

Yeah, that is what I think that might /be/ wrong, but I'm unable to find any info on that.

[hollow sorrel]

are you calling this from a burst compiled job?

[cerulean wren]

Ah, and overall, it does compile the code, but fails to build the player.

No, I'm not even calling this code, it's just these 2 files.

And while I'm building the player it logs the error.

[hollow sorrel]

ah

well first off those burstcompile attributes will at best do nothing, i don't think you need to put them on static classes/methods unless you're using function pointers

might be causing your issue even since it's erroring during building not executing

[cerulean wren]

I'll look at it

[hollow sorrel]

i said first off but that's the only thing that stands out to me 😅

[cerulean wren]

Ok, it does work when I remove the [BurstCompile] class atribute from the BurstClass struct.

[hollow sorrel]

sounds like that's the issue then, burstcompile on class tells burst to look for burst attributes in that class, but it's meant for functionpointers not for static methods
should be able to get rid of the method attributes too since they shoul be doing nothing now
if you're executing these static methods from a bursted job they'll already be burst compiled without using attributes, assuming they fit the same criteria as burst jobs (no managed objects etc)

[cerulean wren]

Yeah, I get it now.
Primarily I was kinda confused when I couldn't find compiled functions in the Inspector. But it totally makes sense. Thanks 😄

[craggy stag]

Hi,
does anyone have experience using CollisionWorld.CalculateDistance?

In my example it trows a bunch of errors, but still gives me the wanted results, and im at a loss.

[UpdateInGroup(typeof(FixedStepSimulationSystemGroup))]
[UpdateAfter(typeof(EndFramePhysicsSystem))]
class...

protected override void OnUpdate()
    {
        var collisionWorld = this.buildPhysicsWorld.PhysicsWorld.CollisionWorld;
        this.Dependency =
            JobHandle.CombineDependencies(this.Dependency, this.endFramePhysicsSystem.GetOutputDependency());


        Entities.WithAll<TagTower>().ForEach(
            (SphereTargeting sphereTargeting ,  DynamicBuffer<Target> targets) =>
            {
                var hits = new NativeList<DistanceHit>(Allocator.Temp);

                var filter = new CollisionFilter()
                {
                    BelongsTo = ~0u,
                    CollidesWith = ~0u, // all 1s, so all layers, collide with everything
                    GroupIndex = 0
                };

                var distanceInput = new PointDistanceInput()
                {
                    Position = float3.zero,
                    MaxDistance = sphereTargeting.Radius,
                    Filter = filter 
                };

                bool hasHit = collisionWorld.CalculateDistance(distanceInput, ref hits);

                //targets.Clear();
                //  for (int i = 0; i < hits.Length; i++)
                //  {
                //      targets.Add(new Target()
                //      {
                //          Entity = hits[i].Entity,
                //          Position = hits[i].Position
                //      });
                //  }

                hits.Dispose();
            }).ScheduleParallel();
    }

The errors:

InvalidOperationException: The previously scheduled job TargetingSystem:<>c__DisplayClass_OnUpdate_LambdaJob0 writes to the Unity.Collections.NativeArray`1[Unity.Physics.CollisionFilter] <>c__DisplayClass_OnUpdate_LambdaJob0.JobData.collisionWorld.Broadphase.m_StaticTree.BodyFilters. You are trying to schedule a new job Broadphase:PrepareStaticBodyDataJob, which writes to the same

InvalidOperationException: The previously scheduled job TargetingSystem:<>c__DisplayClass_OnUpdate_LambdaJob0 writes to the Unity.Collections.NativeArray`1[System.Int32] <>c__DisplayClass_OnUpdate_LambdaJob0.JobData.collisionWorld.Broadphase.m_DynamicTree.BranchCount. You are trying to schedule a new job Broadphase:AllocateDynamicVsStaticNodePairs, which reads from the same Unity.Collections.NativeArray`1[System.Int32] (via AllocateDynamicVsStaticNodePairs.dynamicBranchCount). To guarantee safety, you must include TargetingSystem:<>

InvalidOperationException: Adding/removing components or changing position/rotation/velocity/collider ECS data on dynamic entities during physics step

InvalidOperationException: The previously scheduled job Broadphase:PrepareNumStaticBodiesJob writes to the Unity.Collections.NativeArray`1[System.Int32] PrepareNumStaticBodiesJob.BuildStaticTree. You must call JobHandle.Complete() on the job Broadphase:PrepareNumStaticBodiesJob, before you can write to the Unity.Collections.NativeArray`1[System.Int32] safely.

InvalidOperationException: Adding/removing components or changing position/rotation/velocity/collider ECS data on dynamic entities during physics step

A Native Collection has not been disposed, resulting in a memory leak. Enable Full StackTraces to get more details.

[boreal forge]

I'm hopping this is the right place to ask about Job related questions. I'm having trouble figuring out how to translate my current working code into a Job. The problem im having is the way i need to store the data

what i need is to be able to work over a "2d array" of points. for each point I have to fill in a list of points

but a struct can't contain a nativeList. and im not sure how to go about storing the information I need

the "2d array" length can be of any (int > 1) times its self. but the list of points in the point struct can be anything between 0 to 255+

[stiff skiff]

Whats the 2d list for?

I assume you meant list since the lengths can vary

[boreal forge]

it is supposed to be an array

the size shouldn't change that often and it will always be count^2 making it always a square

[stiff skiff]

Then can't it just be a normal array?

[boreal forge]

does Jobs and burst work with a normal array?

[stiff skiff]

I mean a normal NativeArray

[boreal forge]

inside of the Job it is a Native array.

inside of the point struct it is 2 Separate lists of floats

but i dont know how many values each will contain

[stiff skiff]

You said its going to be count*count

But still, what is the list of points for?

a 2d array is almost never the solution to a problem

[boreal forge]

Whats the 2d list for?
@stiff skiff I assumed you were talking about the 2D array in the job

the list of points of if for holding Y values of hit point from a raycast

This is what my working code looks like right now (Not using Jobs)

its getting the hit points in a grid of points

depending on criteria each hit point is either a free point or a blocked point

[stiff skiff]

Then why not flip the data structure around?

[boreal forge]

What do you mean?

[stiff skiff]

(We've resolved the conversation in DM)

[royal steeple]

(Sad, it's usually nice to see it and learn from it :p)

[stiff skiff]

The result was having 2 NativeQueue<(int RayIndex, float value)> (obviously with an actual struct)

1 for the free list and 1 for the blocked list

for the whole job. instead of 2 lists for each ray

[radiant sentinel]

Hello can i pass 2GB to job?

Can i wait as async to complete a job?

[odd ridge]

yes

job.Complete() will wait to complete the job

[radiant sentinel]

@odd ridge thank you
Its wait on main thread , can i call it async?

[boreal forge]

can you not use a NativeList or NativeQueue in a IJobParallelFor?
invalidOperationException: GeneratePolls.freePoints is not declared [ReadOnly] in a IJobParallelFor job. The container does not support parallel writing. Please use a more suitable container type.

[coarse turtle]

There are ParallelWriter versions iirc

so NativeQueue.ParallelWriter

[boreal forge]

ah that must have replaced .concurent

Ill try ParallelWriter

[boreal forge]

apparently you cant do a raycast job inside of a job... F#$@....

[spark glade]

@spark glade are you switching animations at all? do you rebuild your graph when you do so? or is it through dfg nodes(and if so did you make a custom dfg node?)
@safe lintel for animations, do you know if there is a way to not have to use subscenes for the conversion flow?

From the UnityAnimation.Examples most the relevant things are within a #ifdef UNITY_EDITOR and only run during the subscene conversion step in the editor.

Ideally I don't have to "bake" my animations into a subscene, but instead can just convert and instantiate from prefabs at runtime somehow (just like with ParticleSystems and HybridComponents) :/

[boreal forge]

Jobs are not as straight forward as I had hoped...
Im trying to call this code inside a job

public static NativeArray<RaycastHit> RaycastHitSortByY(ref NativeArray<RaycastHit> hits, int startIndex, int maxHits)
{
  RaycastHit temp;
  int j;

  for (int i = startIndex + 1; i < maxHits && hits[i].collider != null; i++) //Error is on this line
  {
    temp = hits[i];
    for (j = i; j > 0 && temp.point.y < hits[j - 1].point.y; j--)
    {
      hits[j] = hits[j - 1];
    }
    hits[j] = temp;
  }
  return hits;
}```
and i'm getting this error
`UnityException: FindObjectFromInstanceID can only be called from the main thread.`

But i dont think im trying to find and object

also is ref the fastest way to pass in a readonly array?

[coarse turtle]

It's probably your hits[i].collider != null that is causing the issue

with can only be called from the main thread

Unity null objects are not exactly null in the same sense as a plain c# object

[boreal forge]

awesome......

[coarse turtle]

I forget what they do in the background, but they do some stuff so it makes it easy to debug

as for ref the fastest way to pass in a readonly array - probably, you could also try in or NativeArray<T>.ReadOnly 🤔

[boreal forge]

is there anyother way to see if a raycast hit is vaild?

[coarse turtle]

hmm i don't really know if there's a better way to check if the hit was valid on a separate thread

[boreal forge]

ah shit im trying to sort a read only array, that certainly doesn't help...

[coarse turtle]

I assume you're using RaycastCommand?

[boreal forge]

Yea

well a user created version of it, because RaycastCommand only returns one hit

https://github.com/cerea1/RaycastJobs

The first invalid result is identified by the collider being null.
this is literally in the RaycastCommand docs... but you can't use it in a Job...

[coarse turtle]

Well on the scripting API page, they pretty much just check it on the main thread 🤔

[boreal forge]

Well yes, but i assumed they would understand that someone may have 1000's of raycasts hits and may want to deal with them in a job

[coarse turtle]

Well maybe one of the other blittable properties in RaycastHit might be helpful. I'm not really sure what their values are if a Raycast doesn't hit

[boreal forge]

I looked through but i haven't seen anything that stands out

[coarse turtle]

hmm sorry, I wouldn't know :/

[boreal forge]

i think triangle index might work. ill go test

nope. doesn't work... damn

[north bay]

@boreal forge I had to do something similar before switching to dots physics. I think i just checked if the hit point or some other property is not equal to default which worked fine for my use case.

[rancid geode]

The first invalid result is identified by the collider being null.
this is literally in the RaycastCommand docs... but you can't use it in a Job...
@boreal forge You can check for the normal too, if it is 0,0,0 then the hit is invalid

[boreal forge]

Thank you both

[steady blaze]

I wonder if there is something like a shift function for NativeArray and if this would be faster than using a list (could always has the same size) and do cs nextElement = list[0]; list.RemoveAt(0);?

[amber flicker]

there's removeAtSwapBack or whatever it's called if that's what you mean?

[steady blaze]

hm, don't think so, array should always stay the same size, just shift all elements down one index (and return element at index 0), like the Shift in javascript

guess i have to keep nativelist, just thought as there is no size change, it could be faster to use nativearray, but also think, when i have to do the shift in my own loop, it will be slower than nativelist

[zenith wyvern]

You could implement a circular buffer using a nativearray. I wouldn't bother unless you're actually seeing a performance problem though

[steady blaze]

yes, seems like circular buffer is the right thing. maybe i could have an integer value for offset, so the oldest element does not need to be index 0, but can be any, so i just need to increment the int by 1 every time.
then read the value @ offset and set value @ offset - 1, and if offset >= nativeArray.length, offset = 0 … ?

[zenith wyvern]

There's plenty of material online on how to write a circular buffer, it's pretty simple

But it sounds to me like you might be trying to optimize for no reason

[steady blaze]

the main thing i want to achieve is better performance as with nativelist, so i think having fixed size and just changing offset, instead the need to copy all elements down one index everytime (+ resizing the needed memory), should be a lot faster … hmm
yeah, not sure, if really needed (yet) - as noise generation is still the slowest part and baking phyiscs colider the second slowest. but it shouldn't hurt to optimise other stuff

[steady blaze]

but yes, circular buffer seems to be exactly what i search for - just wonder how to implement, as i would like to hide the circular buffer code/values from the Job. As nativearray seems to be a struct, maybe create a struct that has a native (or managed-array) and the needed values and methods

guess i will just add it on my todo-list and do it later, when i better know how to order stuff using just structs (normally I would create a subclass, as i am used to that)

Also a thing I wonder: I have the NoiseGenerator and there a public static method to generate noise (that again calls an IJobParallelFor for that) and return the result as a float[] - but in the main class, i then need to convert the result to a NativeArray to pass it to the meshing job.
But I don't think it is the right way then, to have NativeArray<float> as return type, and persistent NativeArray<float> in the main class.

Guess it would be the right way, to pass the persistent NativeArray<float> to the NoiseGenerator as Parameter that then get's filled there, or am I wrong with that assumption?

[boreal forge]

Ive got a question about about the Unity Physics Package, can you run queries against colliders while not in play mode? I'm writing an editor tool that needs to check raycasts queries. And I'm worried because (if im reading the documentation correctly) you have to convert the gameobject to an a physics entity and I don't know if that works in editor mode. Does anyone have any insight that could help me?

[amber flicker]

@boreal forge yup, it's certainly possible afaik - there are quite a few subtleties/edge cases so it might take a while to get it working 100%. i.e. if subscenes are closed you might need to manually create a world, whether a subscene is open or closed has some small differences etc

[boreal forge]

Awesome, do you by any chance have any example code that I could read up on? Ive never used the ECS side of dots yet

[amber flicker]

conversion generally happens at edit-time - ideally conversion shouldn't happen at runtime but if it did, obviously an editor tool wouldn't be expected to e.g. raycast against them. Sorry, almost no docs exist about this stuff and it requires a lot of trial and error.

[boreal forge]

No worries, thanks for the help. I'll go do some trial and error

[amber flicker]

good luck! I'd get comfortable with the different conversion worlds and subscenes and what happens when before introducing physics.

[boreal forge]

all this just to get some raycasts inside of jobs... hahaha ill look into man thank you

[safe lintel]

hey timboc have you spent much time in looking at dataflowgraph?

[amber flicker]

No... I installed it, looked at some of the examples and then went... I don't understand any of this.

Bit beyond me tbh.

[safe lintel]

yeah, trying my best to get a grips with it and not sure if im wasting my time - not sure if this is really something they expect many people to be touching this or if its really more of an internal tool to facilitate stuff like animation(saw some mentions of dspgraph in the examples so i dont know if eventually they will also have some sort of overlap)

[amber flicker]

yea... making my animation/tweening lib I was like "ah man, another new dots thing you may one day be able to tween with"... I took a look and I was like.... .... ... I don't know. What is this? What have you worked out? What is it beyond an interface with an Update method?

[safe lintel]

where they started talking about simulation and rendering i kinda mentally checked out, need much more time to brute force cram it into memory

i did see nodes can be burst jobed, though not really sure why virtually every single animation example is mainthread without burst

[amber flicker]

Unfortunately the last one I tried they had broken so I haven't actually tried the animation examples yet. I assume it's very performant?

but without burst? maybe it's just early

[safe lintel]

so far all the dfg examples seem to work for me

[amber flicker]

yea they fixed it on the latest I believe

[stone osprey]

why are some of my entities marked as "Clean Up" entity ? What does that mean ?

[amber flicker]

that's the ISystemStateComponentData's

[stone osprey]

So is that a component ? Would be usefull if we could query for "Clean Up" entities ^^

[amber flicker]

yea.. think there's something a little bit nasty with that.. like if you mistakenly declare a CleanUp component of your own it clashes but their CleanUp tag is internal or something.

Basically you shouldn't touch it is the reason

as it's something the Unity systems use to destroy the entities that have ISystemStateComponentData's - it doesn't destroy the entity until there are 0 components left so the idea is you manually remove the ISSCDs

[stone osprey]

Alright thanks ! 🙂

[stone osprey]

structs are copy by value right ? so when i do something like "transform.pos = transform.previousPos" and both are vector2, then those should be two different objects, right ?

[boreal forge]

hmmm im able to start the ECS editor world but there are no entities in it. I'm using this bit of code to start the world

public void OnEnable()
{
  if (EditorApplication.isPlaying) return;

  DefaultWorldInitialization.DefaultLazyEditModeInitialize();//boots the ECS
}
``` Anyone know how to get a gameobject in the scene to be converted into the editor world? It converts in playmode so i know its working correctly.

[amber flicker]

@stone osprey structs are value types yes... transform is usually a class so not totally sure which bit you're asking is a different object

@boreal forge just put a gameobject in a subscene (right-click in the hierarchy and choose create subscene from selection). I feel like I should mention in case you're new to this all that conversion only supports a very small subset of Monobehaviours by default. Say you were making a 'scatter' tool for the asset store... don't waste your time making a jobified raycast system using dots imo - users having to make everything (like terrain) entitified is a substantial ask

[boreal forge]

I'll try the subscene and thanks for the heads up!

hmmm @amber flicker there is now a SceneSection and a Scene in the entity debugger but I'm not seeing the cube i dropped into the sub scene. The cub has a Physics Body and a Convert to Entity scripts attached. is that the correct way todo it?

[amber flicker]

guessing you don't have the hybrid renderer package installed

[boreal forge]

Yea I do

[amber flicker]

you shouldn't need the convert to entity scripts on it anymore

[boreal forge]

ahhh my bad

[amber flicker]

you'll also only see the entity in the converted world I believe (dropdown in entity debugger)

[boreal forge]

I put it below the sub scene not in it

I thought a subscene worked like when you have two scenes loaded... my bad haha

[amber flicker]

it's literally just a gameobject with a monobehaviour and the contents are its children 🙂

[boreal forge]

Entity debugger still doesn't say it has the cube

its name should show up right?

[amber flicker]

in the converted world, not the default one, yes

but it'll only have a name if the subscene is open I think (otherwise it'd be like Entity 1)

[boreal forge]

Converted scene subscene has zero entities

and the filter is empty

[amber flicker]

screenshot?

[boreal forge]

let me send one

[amber flicker]

win+shift+s in case it's handy

[boreal forge]

im on mac so cmd+shift+5 haha

[amber flicker]

what happens if you remove the box collider? I haven't used physics but wasn't it replaced with physics shape or something?

worth a quick try without the physics components

[boreal forge]

just removed both the collider and physics and its still not in the entity list

I made sure to save the subscene too

in play mode the cube does show up in the subscene

[amber flicker]

ah have you checked the editor world?

[boreal forge]

I checked both

editor and converted scene

[amber flicker]

yea it's weird, I think that should be working

e.g.

might be worth a Unity restart? Which package versions & unity version are you on?

[boreal forge]

unity is 2019.4.8f1

and im using the recommend or higher for the entites

and ill try a restart now

[amber flicker]

you'll definitely run into issues on 2019 eventually (it's capped at entities 0.11 for a start) but the screenshot above is from 2019.4 so that much should at least work

[boreal forge]

hmmm still not showing up after a restart

[amber flicker]

sorry, not sure what to suggest - you see them in the entity debugger when you hit play?

[boreal forge]

yea i see it in playmode

[amber flicker]

how about if you close the subscene? (the converted subscene will be empty so check Editor World)

[boreal forge]

thats strange as soon as i hit the check mark on the sub scene to turn it off 3 new entities show up

[amber flicker]

hmm perhaps a rendering/update bug

[boreal forge]

one of them seems to be my cube though

So i just need to have the subscene turned off for it to work... thats strange

[amber flicker]

well.. I need to shoot but quickly, what's happening is when your subscene is open your monobehaviour & entity versions kind of exist simultaneously and the entities are kept in a subscene world. When you close a subscene it only exists as converted binary data sat ready to basically load straight into ram. Thus the entities that were in that subscene world are now in your editor world (even if the entity debugger isn't necessarily showing them).

[boreal forge]

it look like its not "off" its just not open for modification

well.. I need to shoot but quickly, what's happening is when your subscene is open your monobehaviour & entity versions kind of exist simultaneously and the entities are kept in a subscene world. When you close a subscene it only exists as converted binary data sat ready to basically load straight into ram. Thus the entities that were in that subscene world are now in your editor world (even if the entity debugger isn't necessarily showing them).
@amber flicker ahhhhh ok

[amber flicker]

yes - converted representation only 👍

[boreal forge]

Thank you so much for your help Tim! You're awesome!

[amber flicker]

you're very welcome - best of luck!

[boreal forge]

now to see if i can get raycast inside of jobs working 🥳 🥳

[tired mulch]

Hello there!

I've been working on a tool to convert the tiles used from the Tilemap Package in Unity to be managed as entities instead.

I've been using some of the code from https://github.com/fabriziospadaro/SpriteSheetRenderer and rewritten and added some code slightly.

It renders all the sprites with the same Mesh with 1 setPass (drawcall) using the DrawInstancedMeshIndirect Method, and it works fine!

But now that I've ran into trying to implement some lighting system I've kind of hit a roadblock. I've looked at plenty of different sources regarding
how I could calculate the light inside the shader: https://pastebin.com/aGK4KxVV

So with the current method, all the instances being rendered have the same Mesh and Material, but different UVs of the texture is used when rendering each instance (using ComputeBuffers and/or StructuredBuffer for multiple instance rendering)

But whenever I try to apply the light effect (Using formula: diffuse = Kd x lightColor x max(N · L, 0)) I get this as result:

I'm open for all kinds of suggestions in how I could solve this. The lighting doesn't even have to be dynamic either and could be prepared and bake beforehand too, but I'm not sure how I would do that!

[safe lintel]

@tired mulch i think you should ask this in the shader channel

[tired mulch]

Yeah I realized that, so I posted in there as well 👍

[boreal forge]

Does anyone know what this error means. Im calling one IJobParallelFor that is calling a dots physics raycast
invalidOperationException: The previously scheduled job GeneratePollsJob reads from the NativeArray GeneratePollsJob.world.CollisionWorld.Broadphase.m_StaticTree.BodyFilters. You are trying to schedule a new job Broadphase:PrepareStaticBodyDataJob, which writes to the same NativeArray (via PrepareStaticBodyDataJob.FiltersOut). To guarantee safety, you must include GeneratePollsJob as a dependency of the newly scheduled job.

it works perfectly in editor mode, but as soon as i go into play mode it losses its mind

[safe lintel]

some things because i can never remember the specifics but: make sure dependencies are set properly, it might need something like
Dependency = JobHandle.CombineDependencies(Dependency, buildPhysicsWorldSystem.GetOutputDependency());
could also be an issue with the ordering, if it needs to be updated before the EndFramePhysicsSystem and inside the FixedStepSimulationSystemGroup

[boreal forge]

ohhhh ok that makes sense

[safe lintel]

ymmv 😉

[boreal forge]

hahaha lets try it and see

hmmm did not help

pollsJobHandle = pollsJob.Schedule(sideCount * sideCount, 64, buildPhysicsWorld.GetOutputDependency());

is this how im supposed to use it?

im trying to make sure my job doesn't get schedule until the physics world is done?

whats weird is that the code works, like the job is still running. But im getting that error.

[safe lintel]

not sure if you need to combine jobhandles beforehand in your case

if you do buildPhysicsWorld.Complete(); prior to scheduling your job, does it still error?

[boreal forge]

let me try

nope that doesn't help

I got it working, It seems to not like the way I'm setting up the job to work in edit mode.

I just have to figure out how to get both to work at the same time

[coarse turtle]

hmm I dont suppose anyone got the dots animation package working with other humanoid models? 🤔

[boreal forge]

I feel like im banging my head against a wall. Would there be any reason that a sub scene with 20 primitive in it, would run 4 TIMES slower then a normal scene with all those as normal gameobjects. Isn't ECS supposed to be faster?

--Redacted--

I had full stack leak trace. now the sub scene runs at 200fps and just game objects run at 400fps. not nearly as bad when it was a difference of 50 vs 200

[safe lintel]

@coarse turtle can you try to set the rig to generic even if its humanoid?

[coarse turtle]

oh

that works thanks @safe lintel

hmm wonder why the rig should be generic tho 🤔

[safe lintel]

snacktime on the forums mentioned something about issues with humanoid

though the terraformer model is humanoid i think so no idea but generic works for me too on a previously humanoid char

[safe lintel]

fyi the dataflowgraph examples are almost essential to understanding animation

[spark glade]

Progress 😍

I'm so fucking pumped

[spark glade]

@safe lintel I remember having issues with the animation import settings in previous versions of the package. I haven't changed things since and everything is still working.

These were the settings I had ended up with:

Iirc Resample Curves and Anim Compression were what made it work for me. Support might be better by now or maybe my animations formats were just not supported yet back then 🙃

[coarse turtle]

fyi the dataflowgraph examples are almost essential to understanding animation
@safe lintel Oh where can I find the data flow graph examples? 👀

ah nvm, didn't know there were samples in the package manager

[pliant pike]

is there a size limit to dynamic buffers?

[InternalBufferCapacity(498)] can't go above 498 without an EntityArchetype component data is to large warning

[amber flicker]

that's just the initial capacity reserved per entity - that capacity can be exceeded anytime, it's just that it'll be moved to the heap

that warning is saying that you're making the entity so large that you can't even one in a chunk

[pliant pike]

I thought it was the number of elements 😕

thanks, probably best to leave that blank then

[amber flicker]

cool - you generally want it to be the lowest most common value you expect so that most of the time you're getting linear access. If that's larger than e.g. 5 though it starts to become a bit pointless as it potentially fragments your entities massively.

[pliant pike]

I mean I'm putting this into a buffer

{
    public float3 worldPos;
    public int2 gridIndex;
    public byte cost;
    public ushort bestCost;
    public int2 bestDirection;
}```

[amber flicker]

how many of those do you expect each entity to have on average? Or are you like keeping them all on one entity? In which case yea, just leave that attribute off.

[pliant pike]

I'm keeping them all on one entity in a dynamicbuffer

[boreal forge]

I've got a question about passing data between Jobs with out hanging up the main thread. Heres some sudo code.

void Update()
{
    NativeQueue q;
    NativeArray  a;

    Job1 = new Job1()
    {
        queue = q
    }
    handle1 = Job1.Schedule();

    //Don't I have to wait for Job1 to finish before I can get the length
    //Of the queue. Thus holding up the main thread.
    a = new NativeArray(q.Length);

    Job2 = new Job2()
    {
        queue = q,
        array = a
    }

    Job2.Schedule(handle1);
}```

So in this scenario im trying to get all the elements from a NativeQueue into a native array

[amber flicker]

you may want to take a look at AsDeferredJobArray()

[coarse turtle]

yes you have to wait for the NativeQueue to fill up before grabbing its length

[boreal forge]

@amber flicker thank you ill look it up

[amber flicker]

I haven't ever had to use it myself but I believe it's meant for the kind of situation you're talking about

[boreal forge]

one more question, say that Job1 computes an int and i need that int in Job2. In the construction of Job2, can i pass in job1 handle to get the int inside of Job2? as long as Job2 is dependent on Job1?

[coarse turtle]

to pass that data you could use a native container (like nativearray) or a NativeReference<int> or a pointer to the int because the int you pass to jobs are copied over and not their actual references

[boreal forge]

NativeReference<int> i;

Job1 = new Job1()
{
  result = i
}
handle1 = Job1.Schedule();
    
Job2 = new Job2()
{
  input = i
}

Job2.Schedule(handle1);```
like this?

[coarse turtle]

Yeah

[boreal forge]

What about this? can you pass a job into another job to access its members?

void Update()
{
    Job1 = new Job1(){};

    handle1 = Job1.Schedule();
    
    Job2 = new Job2()
    {
        jobHandle = handle1
    }

    Job2.Schedule(handle1);
}

Job2 Execute()
{
    jobhandle.result;
} ```

[coarse turtle]

never tried that exactly

don't think it works for all cases, depends on the struct's content and if the assigned value are all value types, you pretty much take a copy of the struct and assign it

[boreal forge]

ok thank you ill look it to it

[amber flicker]

I'm not sure what the above is supposed to represent exactly. If it's referring to two jobs being in different systems, you can do that through World.GetExistingSystem<SystemA>().resultQueue for example - though it tends to be nice to avoid inter-system dependencies like that where possible imo.

[boreal forge]

I think worlds are part of ECS right? im only using jobs right now. And im just trying to learn about passing data between jobs. What options are available.

I was working with ECS last night but not right now

[coarse turtle]

Well passing data between jobs is largely with NativeContainers/Pointers

there's also SharedStatic from burst side if you need to pass in static mutable data

[boreal forge]

oh ok thank you

[coarse turtle]

never used it before, but it is an option

[amber flicker]

and then of course, stuffing something on an entity / singleton

[boreal forge]

awesome thank you guys

[zenith wyvern]

I don't think you can have a job handle inside a job

Or maybe it's just burst

[green path]

Hi, I'm new to DOTS. I'm just wondering if its possible to get a NativeArray<T> of Entities with a specific ComponentData?

[zenith wyvern]

https://docs.unity3d.com/Packages/com.unity.entities@0.16/manual/ecs_entity_query.html

[green path]

I think I'm dumb

Its saying T for ToComponentDataArray must be a reference type @_@

https://gyazo.com/65550f06ef97c156b8f2e93fb19b9101

I'm trying to get a nativearray of this

[coarse turtle]

yeah that should work, might be the IDE, does it compile in Unity?

[green path]

Let me test

Brb

https://gyazo.com/a9af9cb2e296ef7fe36bc36deac0d367

I think it accepts only classes :c

[north bay]

You have to specify an allocator that it should use

[coarse turtle]

ah, there might be a different API call

[green path]

Oh ok let me try

Oh nice now it works

Apparently I was using another version

Thanks

I have another question

Say I do this

        ECs = GetEntityQuery(typeof(EntityComp)).ToComponentDataArray<EntityComp>(Allocator.Persistent);

And then I create another entity with EntityComp componentdata

My question is, would ECs be updated?

[coarse turtle]

i assume you're just calling it once?

[green path]

Yeah

Before creating the new entity

[coarse turtle]

yeah probably not, tocomponentdataarray would only gather the entities at that frame, so it doesn't know it exists prior, also I'm pretty sure the structures are copied over and not direct pointers to the component data in the chunks

[green path]

Rippp

I thought they would implement their own nativearray internally to store entities with the same componentdata

Because from what I read, NativeArray is like a pointer to unmanaged memory

[coarse turtle]

Well you can use GetComponentDataFromEntity<T>

and access via Entity

[green path]

I want to keep an update collection of specific entities

So I can access them via index

[zenith wyvern]

EntityQuery has a CopyFromComponentDataArray method so you can get the array, make changes, and then copy it back

I assume it's pretty efficient

[green path]

What's the difference between the copy and .ToComponentDataArray<EntityComp>(Allocator.Persistent);

[zenith wyvern]

I don't understand the question. It's CopyFROMDataArray. As in it take the array that you copied earlier and writes the contents back to the entities

[green path]

Oh

Yeah me dumb

Do I have to do that? I thought changing the contents of the ComponentData itself would work @_@

[zenith wyvern]

If you want to modify a bunch of entity components in bulk without using ForEach then that's a good way to do it

But I would say just do a foreach instead. If you can.

[green path]

But say if I do ECs = GetEntityQuery(typeof(EntityComp)).ToComponentDataArray<EntityComp>(Allocator.Persistent);

And I loop through ECs

Modifying their values

Would it reflect on the entity?

[zenith wyvern]

No. ToComponentDataArray is giving you a copy. The allocator just refers to how you need to dispose it

[green path]

Rippp

[coarse turtle]

yes it's doing a memcpy here

[green path]

Is there somehow I can store references to them

[coarse turtle]

that's the job executed for ToComponentDataArray<T>(...)

store the entity for easy access is the simplest way

[zenith wyvern]

Yeah the entity is the reference

[green path]

Ohhh

So I store the entity

And I do Entity.GetComponentData<T>

Or whatever it is called

I can't recall lol

[zenith wyvern]

If you're in a system it's just GetComponent. But keep in mind random access like that is pretty slow

[green path]

But if I store specific entities in a nativearray

Its no longer random access if I get by index right

Wait can you even store entities in nativearray

🧐

Oh its a struct

[zenith wyvern]

If you're using GetComponent it's random access

[green path]

Oh that sucks

So there's no way I can like store a reference to the compdata?

[olive kite]

How do you access the physicscollider's collisionfilter component data? to change the collision filter on an existing entity.

[boreal forge]

Really quick question is this allowed? NativeArray<NativeList<float>>

I'm not getting compiler errors with it but I'm getting errors else were

nvm im getting an InvalidOperationException with it

[safe lintel]

no, cant have nested native stuff

[safe lintel]

@olive kite collider.Value.Value.Filter = limb.Filter;

[olive kite]

thanks!

[boreal forge]

@safe lintel is this also not allowed? NativeHashMap<int, NativeList<float>> it looks like people were using it in 2018 but I'm getting an error trying to create the NativeHashMap

[safe lintel]

where were people using it?

[boreal forge]

https://stackoverflow.com/questions/52460051/unity-job-system-and-multi-dimensional-arrays

[safe lintel]

maybe the safety mechanisms werent in place to disallow it then? i could be wrong but i really dont recall any instances of being able to nest native types

[boreal forge]

man thats a bummer... no worries thanks though

[coarse turtle]

well you can always do NativeHashMap<key, IntPtr> where intPtr points to some unsafelist, but at this point why not just use NativeMultiValuedHashMap 🤔

[boreal forge]

@coarse turtle Because I'm brand new at Jobs and the new collection system never new NativeMultiValuedHashMap existed, thank you for point me in a new direction🥳 While I look that up, how does one use pointers in C#. I used them plenty in C and C++ but ive never used them in C#

[coarse turtle]

Uh usually in the unsafe context

you can use a pointer - like c/cpp, you can declare them naturally with primitive types

but for more complex things like objects, in C# you typically marshal them

[boreal forge]

Marshal?

[coarse turtle]

it's kind of like "serializing" C# managed memory to a native memory layout

https://docs.microsoft.com/en-us/dotnet/standard/native-interop/type-marshaling

[boreal forge]

Do I need anything special to make them work with Jobs and Burst? or can I just look up normal C# tutorials?

[coarse turtle]

well in the context of jobs + burst, stick with primitive types/structs with blittable data

there's also Unity.Collections.LowLevel.Unsafe namespace if you're interested in looking at some similar c/cpp functions

you have Malloc, MemSet, Free etc in that namespace

[boreal forge]

I will look into those thank you. Also Unity doesn't seem to have any documentation for NativeMultiValuedHashMap?

[coarse turtle]

https://docs.unity3d.com/Packages/com.unity.collections@0.14/manual/index.html

i mistyped it, it's NativeMultiHashMap

[boreal forge]

ah there we go thank you

so for NativeMultiHashMap I can just store as many floats as I want per 'index' or key, and treat it like its a list of lists?

am i reading this right?

[coarse turtle]

yea pretty much.

So you can do

key: 1, values: a, b, c, d, e, f
key: 2, values: z, x, y, w```

[boreal forge]

alright perfect thats exactly what I need, thank you so much

[boreal forge]

Im very confused. Im getting an error that says the hash map is full. Im just doing testing so I set its capacity at 4 and then tried to add 4 things to the map. The first 3 work fine but the forth one throws an error?

All 4 entries use different keys and values.

And isn't setting the capacity just telling it how many unique keys to expect? Can it not grow bigger like a list?

[coarse turtle]

capacity is the maximum you can reserve

you can't exceed the capacity

if you do happen to exceed it, you would have to reallocate and increase the capacity

so typically it's better to know how many elements you can expect and reserve the right amount

or reserve an estimation + some padding

[boreal forge]

so the maximum amount of values not the maximum amount of unique keys @coarse turtle?

So its more of a 2d array then a ragged array?

[coarse turtle]

well you can have raggedness in it

[boreal forge]

Right but i mean memory wise?

[coarse turtle]

not sure, best to look at the source on how they reserve memory

[boreal forge]

Well that really only matter later if I can get this working. I set the allocated size to more then 2 the maximum it should excpirence and im still getting a map full exception.

I'm re using the hash map every frame, but at the end of the frame once all the jobs are done I call clear on it. that should make it empty right?

[coarse turtle]

yea

[boreal forge]

hmmmm

[zenith wyvern]

It sounds like you should be using native stream

Based on how it sounds like you're using it it sounds like exactly what native stream was made for

[boreal forge]

Basically what I'm trying to represent is a 2dArray of classes, where each class holds a list of points. So I transform the 2dArray into a 1D Array, and then using the multi hash maps to hold the list of points for each index.

What is a native stream?

And I got it working, I was setting the size wrong in one place but not another

[zenith wyvern]

https://docs.unity3d.com/Packages/com.unity.collections@0.2/api/Unity.Collections.NativeStream.html#sidetoggle

You can look up the tests in the collections package folder to see how it works

[boreal forge]

I'll take a look thanks man

[hollow mist]

I have a simple situation that seems somehow challenging: in a job, I want to do something like entities.foreach() over a component type and count all that have a certain condition... any advice?

[rancid geode]

You can split into 3 jobs (the part before the counting, the counting itself which would be an entities.foreach ans the part after the counting), juat use native containers to link the necessary data

Another option is to use random access in case you are looking for simplicity and not worring about the ultra-optimal performance

[hollow mist]

@rancid geode not sure I understand how I'd use native containers to link the data

[zenith wyvern]

The only way to get data out of a job is using a native container. For a count you can just use NativeReference<int>

You create the container first then pass it into the job to populate

[scarlet inlet]

if I implement ICustomBootstrap, would I get a default world or I have to create it?

rephrasing it would be: I don't know how to get the default world as I don't have World.Active anymore

[safe lintel]

World.DefaultGameObjectInjectionWorld is the new active

[scarlet inlet]

yes I was aware of the field, I hoped this wouldn't be the answer tho

if I call DefaultWorldInitialization.Initialize("default"), would replace the automatically created world?

[safe lintel]

ah not sure in this context

[scarlet inlet]

the comment says: /// Initializes the default world or runs ICustomBootstrap if one is available.

that I gues means I shouldn't call it from inside a ICustomBootstrap

var world = new World("Custom world");

            var systems = DefaultWorldInitialization.GetAllSystems(WorldSystemFilterFlags.Default);
            DefaultWorldInitialization.AddSystemsToRootLevelSystemGroups(world, systems);

            World.DefaultGameObjectInjectionWorld = world;

but then I was wondering: wait a sec, but shouldn't there be a default world at this point already?

if so, it would be awkward to get it through World.DefaultGameObjectInjectionWorld, but I wouldn't be surprised

oh I see I forgot I can use this #UNITY_DISABLE_AUTOMATIC_SYSTEM_BOOTSTRAP

and create it myself

[north bay]

I am looking for a forum thread in which someone showed his implementation of optional components for entity iterations, does anyone remember something like that? I just cannot find it anymore.

[north bay]

Nevermind, just found it https://forum.unity.com/threads/can-there-be-entities-foreach-override-for-optional-component.973539/

[scarlet inlet]

can ComponentSystemGroup be sorted with UpdateBefore and After? I don't remember

let's say I want a group that ticks before InitializationSystemGroup and another after PresentationSystemGroup

I don't really need to do it automatically, as I can tick it myself, but I was wondering

[hollow sorrel]

yes

[scarlet inlet]

thanks Scorr, but if I am adding them directly to the world, and not inside another group, what put them in the right order?

[hollow sorrel]

oh you're talking about the top level groups

hmm

[scarlet inlet]

yes

[hollow sorrel]

not sure bout those

[scarlet inlet]

yeah I agree, but I can tick them manually

MineBefore, world.update, mineafter

[hollow sorrel]

yeah i guess that is the way to go

i don't think they took custom top level systemgroups into account since world.update just ticks init/sim/presentation groups hardcoded

[scarlet inlet]

yes

I saw

I guess mine is a special case they didn't think of 🙂

[hollow sorrel]

for my custom worlds i didn't bother and just put all the custom stuff in simulationsystemgroup and leave the other ones empty

[scarlet inlet]

funny enough I was doing the same, but in my custom world I add the default systems, including havok ones

havok now uses the initialization group

so I need to tick the whole world

[hollow sorrel]

ah

[hollow mist]

@rancid geode @zenith wyvern thanks for the tips.. I'm trying to get that working, haven't really used native containers really

I'm trying to modify the value of the NativeReference<int> inside a job initiated with Entities.ForEach(...).Schedule() and am getting " container does not support parallel writing" errors -- can I not use this in such a way?

[zenith wyvern]

I thought you would be able to

I'll test it

@hollow mist Works fine for me https://hatebin.com/ifonrhfuhn

If you're trying to use it with ScheduleParallel then that error would make sense

[hollow mist]

@zenith wyvern I'm using a JobComponentSystem -- think that would make a difference? also, the only reason I'm using a JCS is because I wanted to sequentially schedule my jobs, passing in the jobhandle from one into the next for sequencing... is this a bad approach?

[zenith wyvern]

You shouldn't be using JobComponentSystem anymore, SystemBase is meant to replace it.

https://docs.unity3d.com/Packages/com.unity.entities@0.16/manual/ecs_job_dependencies.html

It automatically does what you're doing with the dependency property

But no it's not a bad approach. It's the default behaviour for SystemBase

[hollow mist]

ahh, nice, thanks for the info! I'll give it a try!

worked, thanks! @zenith wyvern ++

[odd cipher]

Hey, how would you store an array/buffer in a icomponentdata? I’m guessing you can’t.

[north bay]

You can store the collections with the prefix Fixed or Unsafe on an IComponentData

[tawdry tree]

You can also use class ICDs, but then you can't use them in job structs or with burst. They also exist outside the normal ECS chunk memory. They're meant for porting code from non-ECS to ECS-
https://docs.unity3d.com/Packages/com.unity.entities@0.16/manual/component_data.html#managed-icomponentdata
You might also want to look up dynamic buffers
https://docs.unity3d.com/Packages/com.unity.entities@0.16/manual/dynamic_buffers.html