archived-dots

[rustic rain]

so if game super little, as in flappy bird

probably not worth

[covert lagoon]

What if you did .Run() instead of .ScheduleParallel() on your jobs that only do cheap iterations on a few entities at most?

[rustic rain]

make sure to put them into according update order, to avoid unwanted sync point

[covert lagoon]

What do you mean?

[rustic rain]

if you do .Run() in the middle of your group where everyhting else is scheduled

it'll force all previous jobs to be complete

which is sync point

[covert lagoon]

Oh

[rustic rain]

and that means a lot of perfomance can be lost, since not enough workload will be scheduled for other threads to steal

[covert lagoon]

But didn't you mean earlier that the overhead of scheduling jobs on worker threads is not worth it if the jobs take too little time to execute?

[rustic rain]

that's has nothing to do with sync points

just 2 different subjects to know

[covert lagoon]

Oh you meant in a system group

[rustic rain]

in other words: I made a small game in a style of flappy bird in Dots. Perfomance was poor, compared to GO version of it. So I remade it in classic UNity and got x2 perfomance.

meanwhile I am doing rn a tycoon kind of game and simulated thousands of entities took me only 2ms of total time on all game logic

[solemn hollow]

thats not entirely true. you force all depending jobs to complete. not evey job. So in some cases it wouldnt be a problem at all. the real problematic snyc points are the ones with structural changes. these force all jobs to complete.

[hot basin]

And if you only .Run() then there is nothing to complete

In this case you will have mainthread only ECS game which should be better for small games

[ionic sierra]

what about a game where you want 10000 instances?

[rustic rain]

that's dots is for sir

[ionic sierra]

what are the limitations of Dots...can they be used with game objects in the same scene?

[covert lagoon]

Yes

[rustic rain]

GO and ECS are 2 different worlds

ECS should be the main one

[ionic sierra]

but its hybrid now...or not?

[covert lagoon]

What do you mean?

Mixing GameObjects and entities is what Unity Technologies refers to as a "hybrid environment of GameObjects and entities," yes

[ionic sierra]

great

[hot basin]

You can but GO can't be multithreaded so it's tricky to get any gains in simple ways

[ionic sierra]

so gameobjects can run on the mIn thread? and entities on the other threads?

[covert lagoon]

There are things that do not have a DOTS equivalent planned, such as the Camera GameObject component and all the GUI stuff, because it is believed that they would not perform much better, so any game using entities will be a GameObject/entities hybrid really

[rustic rain]

@ionic sierra https://docs.unity3d.com/Packages/com.unity.entities@0.50/manual/ecs_core.html

I recommend you look up manual

it explains what ECS is

[covert lagoon]

Unity executes GameObject/MonoBehaviour OnUpdate methods only on the main thread. The same goes for DOTS systems, but they're more likely to schedule jobs on worker threads to parallelize the actual updating of entities.

[ionic sierra]

couldn't you make UI very limited. and the main thread...with gameobjects, and then 1000's of entities in ECS

[covert lagoon]

What do you mean by "couldn't you make UI very limited"?

I doubt that the UI is the bottleneck in any game

You don't have to make the UI "very limited"

You can and probably must have GameObjects which will be updated on the main thread

But you can also have thousands more entities which will be updated faster by jobs scheduled to run in parallel on several worker threads

[ionic sierra]

great.

so then i heard it is composition over onheritance

do i need to learn some basic composition book?

[covert lagoon]

There's not much to learn about composition

I think you should read the Entities package's manual: https://docs.unity3d.com/Packages/com.unity.entities@0.50/manual/ecs_core.html

[ionic sierra]

Yeah I am making my through it.

[covert lagoon]

There are also several conference presentations about DOTS on Unity's YouTube channel

[ionic sierra]

Arebthey still relevant?

i have seen most of them

[covert lagoon]

I'm sure the concepts definitely are, but some parts of code examples may no longer be relevant because of significant updates to the APIs

[ionic sierra]

but i was a bad coder then so it didnt make sense.

[hot basin]

but idea behind them is the same

[covert lagoon]

Yeah that's what I meant by concepts

[hot basin]

yeah, figured that out after sending message 😛 sorry

[rustic rain]

any idea at what value does sin/cos do a full cycle?
math.sincos(curTick, out float sin, out float cos);

Basically, what would be modulo value for ticks?

hm

it says it's in radians

I assume that value would be 2

[hot basin]

2PI?

[viral sonnet]

anyone tested burst 1.8?

[sharp stump]

Okay, rendering... rendering is important. Trying to update the RenderMesh component to assign a mesh. How do this? What can I pass in as a mesh and how'n the heckfire do I get it in there?

Rendering seems less obtuse then before in dots .5, but not NOT-obtuse 😄

[rustic rain]

ughm?

What are you trying to do?

[sharp stump]

Assign a mesh to the RenderMesh component. Y'know, so I can see shit 😄

right now though I am reinstalling because I realized I had the wrong version of Unity for the 100,00th time

[rustic rain]

So, what is troubling you about it?

[sharp stump]

um, how to do it, and how its done, and that.

um... shit...

[rustic rain]

it's a simple shared component

You can add it in entitymanager

[sharp stump]

I'm sure I'll get it

[viral sonnet]

If you want the easiest way and also the recommended one: Create a subscene in your scene and put the GOs in the subscene. They are automatically converted to an entity with the correct RenderMesh and material. You need to install the HybridRenderer package too, otherwise those entities are not rendered in runtime

Then take a look at the DOTS hierarchy what the conversion process actually created. What was created/converted can be created manually too.

[misty wedge]

It ended up being a bug in netcode 😦

I assume they've fixed it or at least added an error message in 0.50, because it's very obscure what is happening and causing infinite memory allocation

[viral sonnet]

you are not on the latest?

[misty wedge]

No, I'm on 2021.3

[rustic rain]

hmm

I have RateManager in my system group

[viral sonnet]

oh boy ^^ well, hopefully 0.51 is just around the corner

[rustic rain]

and I want to have custom attribute UpdateOnStart which will do one update cycle on all those systems, irrelevant of rate state

basicailly, if game starts paused (not Unity pause, but internal pause in system group), I want to run all those systems anyway

[rustic rain]

Is there a way I can do that?

[viral sonnet]

ouch

how would you determine that Start is happening? at that point you could just call Update on the Component group, like Simulation

[rustic rain]

well, I simply want to run code in actual Update

with some boolean set to false, once first update is over

Problem is that updating systems is not that simple xD

[viral sonnet]

it is, just get the component system group and call update

[rustic rain]

but all systems exist in it

meanwhile I only need to do update once

on certain systems

doing it on other systems might cause unwanted behaviour

[viral sonnet]

you can also get the systems individually from a MB and Update.

[rustic rain]

oh

wait really?

[viral sonnet]

yeah sure, if any jobs are scheduled though it could trip up the dependency system if you call it in between so make sure you call .Complete if that happens

[rustic rain]

bruh

I didn't know that's a thing

kek

[viral sonnet]

hehe, I only learned this when doing a simulation fast-forward once. it's all really straight forward

[rustic rain]

                if (sys.GetType().GetCustomAttributes(typeof(UpdateOnStart), true).Length > 0)
                {
                    
                }

Is that enough to check system class for UpdateOnStart attribute?

[viral sonnet]

i'm not sure, looks good to me

[rustic rain]

yeah

it works

nice

it's aaaaall coming together xD

[hot basin]

so was it 2 or 2pi?

[rustic rain]

tbh, doesn't matter

I didn't use modulo

I just turned value into double

xD

and with it's precision, I'll never run out of it unless player will play for literally years

[hot basin]

👌

can I put array into blob array?

[misty wedge]

You can put a BlobArray in a BlobArray

e.g. BlobArray<BlobArray<int>>

[hot basin]

but can I do this: public BlobArray<Action> Actions;
and

public struct Action
    {
        public BlobArray<int> AxisID;
    }
```?

[misty wedge]

Sure

[rustic rain]

when do Conversion systems run relative to Authoring classes?

[hot basin]

but I need to remember to blob.Allocate() everything yes?

[misty wedge]

Yes, you need to allocate an array for every index

[hot basin]

❤️ thanks

[viral sonnet]

blobs are really great when you get around their usage

they are also sequentially layed out in memory. I painfully confirmed this with debugging pointers 😄

not totally linear though but pointers are just behind the blobRoot

[rustic rain]

what the

why it errors

em = EntityManager

bruh

I forgot entity

lol

[rustic rain]

Omg

lack of rendering tools in ECS

feels so bad

I need line renderer and trail renderers so bad

but hybrid approach is such a pain

[hot basin]

it shouldn't be hard to make your own

as mesh tools got some love lately

[rustic rain]

welp, so far I only have guesses on how to do it

but tbh

that sounds like the only real solution

hybrid approach in this regard is more of a patchwork

[rustic rain]

any tip tho how it works?
It just creates tons of meshes?

[hot basin]

it's more about editing

nice tutorial with use of this API: https://catlikecoding.com/unity/tutorials/procedural-meshes/

[viral sonnet]

particle rendering is quite good. the need for a dots solution is not that important. line renderer on the other hand, yeah, either an asset store package or throwing one together

[rustic rain]

but how does throwing one together work?

let's say for trail renderer

do I just create thousands of meshes or?

[viral sonnet]

i would make trails with a particle system

[rustic rain]

some procedural giant mesh?

[rustic rain]

dots has particle system?

[viral sonnet]

nah, go one. gpu anyway

[rustic rain]

that's still GO approach

which makes me hate my life

xD

[white island]

Okay so. How do I get around not being able to make a nativearray of native containers

do i make an array... of pointers?...

well if there are lists they could be stale

Also: How can I search through a nativearray in a job to find for example a float3 with an x value of 25

normally I'd use an Array.Find or a LINQ but those aren't burstable

[viral sonnet]

Why do they have to be 2 dimensional? Can you flatten them? If they are for entities, a DynamicBuffer is the more sane option. Otherwise, UnsafeContainers are the answer

[white island]

I'm trying to have an array of a KD tree I got online, that has an internal NativeArray so I can't store it in the array

and pass it to a job

boy I wish I had Rust's boxes right now

[viral sonnet]

Sadly there's no UnsafeArray but you can make one yourself as it's just a struct with a pointer and a length

[white island]

I like the dynamicbuffer idea but i don't know how largeeach KD tree is

[viral sonnet]

yeah you could model the KD tree as entity. But honestly, I'd go with the Unsafe option. If you don't want to write one yourself you can use an UnsafeList

[white island]

Ogh but I don’t want an unsafe class… the trees are stored persistently in a mono behavior

[white island]

what namespace is that

[viral sonnet]

Unity.Collections.LowLevel.Unsafe

a NativeList itself has only internal UnsafeList<T>* m_ListData; You're just missing the safety stuff around it. Leak detection, etc...

this is how NativeList creates it: m_ListData = UnsafeList<T>.Create(initialCapacity, ref allocator);

[white island]

oh.. okay.

Well I am disposing it so all good.

[white island]

now, is there a way I can search a nativearray using a predicate like Array.Find()? a lambda expression like n => n.x = 4

[viral sonnet]

not really, linear search is quite of slow. AFAIK linq Contains or smth is pretty dumb and just goes through the array until it finds it

[white island]

if I loop through everything that's O(n) and that's no good

oh does it

well, I have no choice then

[viral sonnet]

sure, hashMap 🙂

[white island]

What about BinarySearch?

hashmap isn't really compatible with my setup unfortunately, not in this case

[viral sonnet]

ah no key? hm

kdtree could get quite big right?

[white island]

it's not the KD tree, it's a node graph

i could write an IComparer

[viral sonnet]

array must be sorted. is it?

[white island]

I have a nativearray of type Node, and Node has a Position value. I just want to find a node with a position

[white island]

uuhhhh no? sorted by what?

oh. by my comparison.

yeah no that won't work

dang, I guess I do have to loop through it. Painful.

[viral sonnet]

what about a hashmap<Position, int> where the int is the index to the array?

really, anything is better than just looping. I did this a few days ago and my program needed 8 seconds for a frame

down to just a few ms with a hashmap

I think I looked up some value in a dynamicbuffer (lots of entities 250k)

[white island]

That might be a good idea. I should construct that outside of the job, right? my node graph will not be changed after it has been created, so

i guess, a point cloud

[viral sonnet]

should work, just keep inaccuracies in mind when they are float positions. if you reuse the same values, no problem

[white island]

yeah no the KD tree and the node graph are using the same set

[viral sonnet]

then it's okay

off to bed now. good night o/

[white island]

goodnight. thanks!

[white island]

God.

[white island]

i could make... a linked list...

...nevermind.

Okay. New idea. In the job I already know which of these trees I need, but not in the entities foreach.

So if I had an array of this managed type, how could I pass it into the entities foreach?

[rotund token]

why don't you just look at unity physics implementation of their bvh and how they handle it

sure they're different containers but they do similar things and would have the same issues you're having

[white island]

Where is it on GitHub?

[rotund token]

it's not on github

just look at the package source

well actually thats not true

it is on github

via needle mirror

https://github.com/needle-mirror/com.unity.physics

https://github.com/needle-mirror/com.unity.physics/tree/master/Unity.Physics/Collision/Geometry

BoundingVolumeHierarchy.cs
BoundingVolumeHierarchyBuilder.cs

probably the 2 primary parts

alternatively just use their bvh unless you really need a kdtree for some reason

[white island]

these are stucts, not classes

I'm very close with this whole kd tree thing, I just have to figure out how to pass them into the entities system

and i dont know how to do that.

because I can't use a this[] on a managed array or list inside of a foreach

wait... can I have a managed array be readonly? will that work?

[rotund token]

well of course they are

because its designed to work in burst/jobs

[white island]

yeah

wait, my thing is also a struct. Right. The problem is I cannot hold them in an array because they have nativecontainers inside of them

so I'm trying to find a workaround

and I can't figure it out

and a BVS won't work because I need a structure that can hold a point cloud and get the closest one to a certain point

[white island]

can a bvs hold a point cloud

[rotund token]

🤷‍♂️ no idea

i was mostly suggesting just looking at how they tackled the problem then applying the techniques to your own work

a quick google has a few papers that seem to do this in a bvh - for example https://ieeexplore.ieee.org/document/6376712

[white island]

I'm getting a little frustrated. It can't be that hard to have some kind of buffer or array or list or Something that can hold something with a NativeArray inside

In Rust, all I'd need to do is Box it, but C# works totally differently so I can't do that

[white island]

How do I get a pointer to a managed type?

[rustic rain]

before you research

you still can't have pointer to managed type in unmanaged components

[rustic rain]

btw, you can hold Unsafe containers inside containers

[white island]

It says I can't?

[rustic rain]

but afaik you need to define beforehand total capacity

[white island]

Hmm how do I do that

[rustic rain]

lemme find example

var chunks = new NativeList<Chunk>(count, Allocator.TempJob);

        private struct Chunk
        {
            public int Mesh;
            public UnsafeList<Vector4> Colors;
            public UnsafeList<Matrix4x4> Transforms;
        }

ngl, I never gave a thought about what they actually are

and now I'm interested

judging by internal fields

it's just a pointer to other container

native container*

[white island]

I need the opposite though, a native container inside an unsafe one

do I just... wrap it in a struct?

[rustic rain]

@rotund token in this case NativeList's chunk count should be amount of chunks? Not smth else?
Since in your selection tool code, you used total entity count from query.

[rustic rain]

I don't think you can have native container inside other container

[white island]

Nuts.

[rustic rain]

I mean

you want to put resizable unmanaged chunk of memory into fixed sized chunk of memory

[rotund token]

dont have code in front of me but ah yes it should calculatechunkcount not calculateentitycount if thats not setup right

[rustic rain]

I might be wrong here

[white island]

Well. since I have the package right here and a nativecontainer is a wrapper for unsafe container (i think) I could just go in and swap them out

[rustic rain]

well, why can't you just opposite

unsafe inside native?

that would make sense and it's possible

and it's the same thing: container inside container

[white island]

thats what im saying.
I'm using a package that is a burst-compatible k-d tree. The point cloud is stored internally inside a nativearray.
I want a nativearray of these k-d trees, but I since the k-d tree uses a nativearray internally, I cannot do that.
So what if I went into the k-d tree package and swapped out the native stuff for unsafe alternatives

[rustic rain]

I think you could retrieve NativeArray from unsafe

when you'd need it

it has pointer to internal buffer

which I assume

can be interpreted as NativeContainer

[white island]

I don't totally know what that means!

[rustic rain]

open up/decompile source for UnsafeList

T* Ptr

[white island]

good lord

not sure how that would help me here

[rustic rain]

well, I'm not sure what you actually want to do with containers either

[white island]

I have a couple K-d trees each corresponding to different sections of a node graph (it's complicated but yes they need to be separate). I want to pass these trees into an entities system. I do not know which trees I need until I am actually doing the job, though. If I am able to pass an array, list, some kind of container in, I will be able to select which I need easily. but I cannot pass in an array because I am not allowed to store this type inside of a nativearray

[white island]

I tried to make a sort of linked list, but the k-d tree struct appears to be managed, even if the point cloud it contains is not.

[rustic rain]

I get it why, you want to do this

but what is actual interface of communication with whatever system you are working?

if it's a method: what argument does it take for those arrays

kind of like this, because I don't really get why any of that even a problem

[white island]

It is a pathfinding job that selects one of these trees to find the closest point in a node graph

well, I suppose I could select which trees I need in the foreach. but I still need to figure out how to pass the array in and I can't do that

[rustic rain]

what argument list of that method

[white island]

which method. the job? closest point?

[rustic rain]

I guess, I don't know what is it yet xD

[white island]

the job takes these parameters in:

public GoalPosition start; //input; where we start
            public GoalPosition end; //input; our goal
            public NativeArray<Node> nodeGraphSource; //input; the node graph
            public NativeArray<Connection> connectionsSource; //input; connection map
            public NativeList<int> outList; //output; paths
            public UnsafeHashMap<int, KnnContainer> trees; //K-D trees, one day
            public NativeHashMap<PointCloudPoint, int> pointCloud;

and the function to get the closest point looks like this

```cs

static int getClosestNode(NativeHashMap<PointCloudPoint, int> cloud, GoalPosition goal, UnsafeHashMap<int, KnnContainer> trees)
        {

[rustic rain]

and you want to find clsest node out of several arrays?

[white island]

each tree corresponds to a "world" the NPC is in. the array contains the correct tree for a given world (each index corresponds to a world).
What this function does is selects the tree for the world that the NPC is in, and finds the closest point to goal

(and then it maps it to the master node graph using the point cloud but that's not relevant)

[rustic rain]

so it takes hashMap

not array

Is that correct?

[white island]

I was trying to use a hashmap yes

[white island]

but then it told me this

so I can't use that

and I am trying to figure out an alternative

[rustic rain]

and what exactly did you do there?

[white island]

error is on this line here:

public static UnsafeHashMap<int, KnnContainer> kdTrees;
//...
kdTrees = new UnsafeHashMap<int, KnnContainer>(worldLUT.Count(), Allocator.Persistent);

this is in the script that builds and manages the trees and the node graph

[rustic rain]

You can have MultiHashMap

if you want container in value

[white island]

how would that help me

[rustic rain]

What is KnnContainer?

what is inside

[white island]

It’s a package off GitHub https://github.com/ArthurBrussee/KNN

[rustic rain]

some complex container, I see

well, I think you either grab all data from inside and put into your own containers to do it in single job

or maybe each job for each knn container

since this container uses Native containers, you won't be able to put it inside other

[white island]

I was trying to make my own k-d tree implementation but it wasn’t working very well

And this sucks because this tree here does exactly what I want it to except for the nativecontainer restriction

Well. I can access arrays inside of foreach but I can’t run it in parallel which was my entire goal

[rustic rain]

you won't be able to have array of such structure

you need to make it fixed size (filled with Unsafe containers instead of natives)

[white island]

What if I made a 4D tree. 3 dimensions of space and one of “world”. Then I just have a single tree

And I don’t have to monkey around with arrays

[pulsar jay]

Is there any way to check an OverlapSphere ignoring bounds? I just want to check if the position of an entitiy is inside the sphere. Should be cheaper than checking its AABB if it isnt necessary.

[karmic basin]

You can do a point distance query

[pulsar jay]

You mean the one in DistanceQueries?

[karmic basin]

Yeah it's already built in in dots physics

[pulsar jay]

But I need to direktliy input 2 points into that method

I dont know the points. I still want to query for all objects on a physics layer

[karmic basin]

Wait a minute actually the point is on the collider if I remember well so still not what you want

[pulsar jay]

Atm I am using OverlapSphereCustom. But that does check intersection with boundingboxes afaik

[karmic basin]

You want to input 2 points you don't know, something wrong in that statement

[pulsar jay]

No. Basically I want a Sphere Point intersection with all physics objects on the layer

[karmic basin]

Ok so what's wrong with first an overlap query to filter first results, then a simple distance check on matches

[pulsar jay]

It is still pretty slow for many entities

and I have to filter the results because I get duplicates

if it would just check 1 position per entity it should be faster and remove the duplicates

[karmic basin]

Sorry got no other simple idea than an overlap or any spatial query first to filter, then the real check on limited results

[pulsar jay]

Ok thx. Thought there should be a simpler way cause its a simpler query

[karmic basin]

I mean the way i see it is "just" a few more lines of code in a custom hit collector but maybe I'm forgetting smthg obvious

[pulsar jay]

Yeah sure it is. But the reason I want to check the position instead of the bounding boxes is mainly because it should be more performant. If I am doing both that wouldnt help 😅

[karmic basin]

Oh ok I see now you want to bypass the bounding box step

I'm slow sometimes

[pulsar jay]

yes exactly. That should also avoid the need to filter bacause it should only return one result per entity

[karmic basin]

Yeah sure a distance check is straightforward but still you don't want to query against everything so need some way to filter

And physics already computes bounding colliders anyway so...

[pulsar jay]

yeah I def need the broadphase

my first implementation was just a naive entity query for all targets + sqrdistance check

which was slower than the OverlapSphere

so best thing would still be to use only position both in broad phase and distance chek

but I guess it might not be so easy to change how the broad phase works

[karmic basin]

This I can't talk about. I did not dig into the broadphase yet so still a blackbox for me. I trust Unity to improve it where need be while I focus on problems I am responsible about :P

[pulsar jay]

I just dug into the collision code and I cannot even find the point where it is iterating over multiple entities.
I only see OverlapSphereCustom -> CalculateDistance -> DistanceQueries.PointCollider -> DistanceQueries.PointCollider -> PointPoint

PointPoint checks the distance between two points. I dont even get where the whole iteration part is hidden 😬

[karmic basin]

the broadphase should be handled prior to any query (the query is done agains a built world representation of the colliders) so I'd look more towards one of the physics systems

didn't launch Unity for months actually so don't remember how they're called

probably smthg like "buildphysicsworldsystem" or close

and btw if any engine uses bounding volume to optimize I'm sure it brings greater value than without, otherwise there would be no point complicating things. Thus I would not try to overcome bounding volumes in the first place

you've seen teh value yourself with your overlap vs distance-check-everything first implementation

[pulsar jay]

yeah I just found out there is a point collider 🤔

this might actually do what I want. there is just no way to author it so I will have to attach it by script

[karmic basin]

the point distance collider ?

[pulsar jay]

no the PointCollider

it is actually a collider. like BoxCollider etc.

[karmic basin]

oooh didnt know this one 😮

[pulsar jay]

you cannot select it from the physics shapes

but its what is internally used for the distance checks

[rustic rain]

I wonder if creating hundreds of unique RenderMesh is a good idea

xD

or maybe I should create my own Component for this case

[rotund token]

would definitely save on chunk memory

[pulsar jay]

How do you guys handle ECB commands that reference potentially destroyed entities? We ran into that problem several times now. It just happens that a system or a command buffer may destroy an entity before an ecb referencing it is run

Is there any kind of safeguard to make the ecbs check if the entity still exists instead of just crashing?

[rotund token]

we use a separate system for destroying that runs after the system used for everything else

i.e.
EndSimulationCommandBufferSystem <- Set, Add, Create, Remove components
DestroyCommandBufferSystem <- Destroy

that's what we do at work anyway

personally for my own projects I just try to really carefully wrote my code in a way that doesn't have this issue

by having clearly defined ownership of lifecycles

[pulsar jay]

yeah I was actually doing the same with the destroy system in fixed update. which worked for the most part. But we just found that we use a MainThread system with run for unloading the levels 😑

I guess this method also has another problem.
It is a public method UnloadLevel on a LevelSystem which uses an entity query. Can anybody tell me if Unity will handle the dependencies properly in this case?

[rotund token]

they wont

dependencies are only handled when system calls Update

the query itself will be fine though

[pulsar jay]

What do you mean by fine?

In this case it works like this:
WinSystem calls LevelSystem.UnloadLevel()
UnloadLevel has a query to find specific entities and destroy the via a command buffer

[rotund token]

the query should be able to get correct dependencies

yeah that's /probably/ fine

though i consider it pretty bad design

[pulsar jay]

yes I know 😬

how would you handle it? spawn an entity with a component which triggers the level unload?

[rotund token]

that seems fine (and what unity would probably do)
or simply just do it in the WinSystem and turn LevelSystem into a standalone struct/helper

[pulsar jay]

But a helper struct cannot (easily) run an entity query can it?

[rotund token]

you can pass in the owner system and do what you want

personally it's a pattern i quite like for re-usable code

but yeah it's not something that necessarily makes sense for this use case

it's hard for me to say without seeing what it's doing

[pulsar jay]

public void UnloadAll()
    {
        EntityCommandBuffer ecb = new EntityCommandBuffer(Allocator.Temp);
        Entities
            .WithoutBurst()
            .ForEach((Entity entity, in Level level) => { ecb.DestroyEntity(entity); }).Run();
        ecb.Playback(EntityManager);
        ecb.Dispose();
    }

Thats what its currently doing

Trying to change it to use the external destroy ecb though

Which is problematic as you have to pass a dependency to the ecbSystem

[rustic rain]

why not just do run

with structural changes

and destroy directly

[pulsar jay]

The run was causing my initial problem. Destroying entities during run causes every ecb that still references it to fail

[rustic rain]

why not do Run after ECB?

[pulsar jay]

How should I assure there is no other system that queued ecb commands this frame?

[rustic rain]

hm

the only thing I worry about is begin sim ecb

everything else seems to be fine, if you run it after end sim ecb

[pulsar jay]

I usually use BeginSimulationECB for the usual stuff and BeginFixedStepECB for destroying

This way they do not collide and physics queries always return valid entities

But using Run breaks it because there might be Systems that ran before this System that added stuff to any of the ECBs

I could ensure that the System can only run directly after the ECB but that does not seem like a good solution to me

[rustic rain]

you can run rigth after them

cause otherwise

you are causing sync point

somewhere you probably don't want it

which probably just sends to waste all scheduling

[pulsar jay]

yeah thats why there are ecbs in the first place

ao it woul make most sense to just use them to destroy the entities

[rustic rain]

then for what this monstrocity?

[pulsar jay]

yeah thats what the code looks like atm. I am trying to change it to use the correct ecb. Problem is it is called from several systems and even GameObjects. So dependency management is a problem

[rustic rain]

Game objects should never access ecs

Only vice versa

Unity recommends to never access world

From game objects

[pulsar jay]

ArgumentException: All entities passed to EntityManager must exist. One of the entities has already been destroyed or was never created. Entity (748:11) was previously destroyed by Unity.Entities.BeginFixedStepSimulationEntityCommandBufferSystem. This command was requested from EnemyEntityDeleteSystem.
Unity.Entities.EntityComponentStore.AssertEntitiesExist (Unity.Entities.Entity* entities, System.Int32 count) (at Library/PackageCache/com.unity.entities@0.50.1-preview.2/Unity.Entities/EntityComponentStoreDebug.cs:273)
Unity.Entities.EntityManager.AddComponent (Unity.Collections.NativeArray`1[T] entities, Unity.Entities.ComponentType componentType) (at Library/PackageCache/com.unity.entities@0.50.1-preview.2/Unity.Entities/EntityManager.cs:888)
Unity.Transforms.ParentSystem.UpdateChangeParents (Unity.Entities.SystemState& state) (at Library/PackageCache/com.unity.entities@0.50.1-preview.2/Unity.Transforms/ParentSystem.cs:317)
Unity.Transforms.ParentSystem.OnUpdate (Unity.Entities.SystemState& state) (at Library/PackageCache/com.unity.entities@0.50.1-preview.2/Unity.Transforms/ParentSystem.cs:418)
Unity.Transforms.ParentSystem.__codegen__OnUpdate (System.IntPtr self, System.IntPtr state) (at <03123a18c5ac42fb99a9907c3248ab1d>:0)
Unity.Entities.SystemBaseRegistry+<>c__DisplayClass10_0.<SelectBurstFn>b__0 (System.IntPtr system, System.IntPtr state) (at Library/PackageCache/com.unity.entities@0.50.1-preview.2/Unity.Entities/SystemBaseRegistry.cs:246)

Now that even happens in Perenting System 😕

That is really out of my control

[rustic rain]

You should centralize entity destruction maybe?

[pulsar jay]

I did. I centralized it in BeginFixedStepSimulationEntityCommandBufferSystem

[rustic rain]

Considering you have way too many things that do this

Do you have special destruction component?

[pulsar jay]

But the parenting system seems to interfere with it now

[pulsar jay]

Yeah a DeadTag for the eneimies

[rustic rain]

So why entity is destroyed when it reaches your system ?

You destroyed it somewhere else

Meaning destruction is not centralized

[pulsar jay]

protected override void OnUpdate()
    {
        var ecb = this.ecbSystem.CreateCommandBuffer().AsParallelWriter();

        Entities.WithAll<DeathMarker>().ForEach(
            (int entityInQueryIndex, Entity e) => { ecb.DestroyEntity(entityInQueryIndex, e); }).ScheduleParallel();

        this.ecbSystem.AddJobHandleForProducer(Dependency);
    }

that is the destruction code

it gets destroyed in BeginFixedStepSimulationEntityCommandBufferSystem

and parent system fails to access the entity

but I dont have any control of parent system. its unitys system

[rustic rain]

Hm

Can you look through project

And search for destroy entity?

Just to be certain it's really the only thing that destroys entities

Wait a second

Where does this system update

@pulsar jay

In fixed or normal update?

[pulsar jay]

Fixed update

because otherwise physics queries will return objects that have already be destroyed

[rustic rain]

So

I suggest you to either create new buffer

Right after your current

Or manually do removal

Cause it seems

Like different actions in buffer get mixed

And when destruction happens first

And adding some comp next

It results in exception

[pulsar jay]

It does not even seem to happen in the same buffer

The parentSystem just does Unity.Entities.EntityManager.AddComponent

[rustic rain]

welp

in this case I can only say, that you have spaghetti

kek

[rustic rain]

yay, I'm getting a great idea about procedural meshes

[rustic rain]

omg, looking how HybridRenderer works

oh no

oh no

[haughty rampart]

hm?

[white island]

so, to make a system that multithreaded-ly calculates paths for entities, I would:
-in the foreach, collect a list of every entity that needs a new path
-afterwards, run the pathfinding job in parallel, with sets of data corresponding to every entity's start and end points
-Take the data and then apply it to everyone in the list
...right?

[solemn hollow]

@white island hmm not sure if i understand what you mean with collect all entities that need a new path.
I would probably just

Entities.Foreach((in NavmeshAgent agent) => 
{
  if(!agent.hasPath)
  {
    CalculatePath();
  }
}).ScheduleParallel();```

so on mainthread you are not gathering anything at all. you just schedule the pathfinding and skip work if you have a path. You could combine this with ChangeFilters that get active whenever an agent reaches its goal to get rid of the if(!hasPath) check.

ChangeFilters seem especially useful when your chunk utilization is low (which mine is for all of my AI stuff...)

[rustic rain]

4k lines in that file

[haughty rampart]

Could be worse

[warm panther]

Hey, quick q: in 0.50, how do I Raycast only for a specific PhysicsWorldIndex?

[cunning perch]

sigh, why does dots physics work from the sample project, but not the one i set up from scratch ☹️ alt-tabbing between the two projects shows no difference

guess ill sleep on it

[karmic basin]

You do your raycast in the context of a collisionworld, so it's already restrained to a single and specific world. Now if you're asking how to retrieve the physics world associated with a specific index, I can't help yet because didn't migrate to 0.50 yet

Maybe that's something you're supposed to track yourself ? 🤔

[white island]

ok, so I can fake component arrays with dynamicbuffers, but how do I fake having lists with components?

[white island]

but doesn't my job have to be declared as an IJobParallel to do that?

[white island]

hey question, the compiler complains that I'm using a this here, but I don't see anything wrong? Unless I'm not supposed to get data from outside sources like this, which I thought I had to. What's up?
https://pastebin.com/brg0pdy3

it helpfully doesn't tell me where in the foreach it is

oh I got it, it was EntityManager

[solemn hollow]

no. Entities.Foreach gets codegenerated to IJobEntityBatch which can run parallel as well.
IJobParallelFor is old API anyways. new API is IJobFor.ScheduleParallel().

[white island]

what about IJobBurstSchedulable

[solemn hollow]

never seen that.
my point was about not getting the list of entities which need a path by looping over them on the mainthread. filter them inside the jobs

[solemn hollow]

dynamicbuffers are lists on entites. why fake anything?

[white island]

yeah I got it eventually

[fickle smelt]

Could somebody explain how to vectorise this loop via Burst? Burst says the "loop control flow is not understood by vectorizer"; https://pastebin.com/N2cL0j3g

[rustic rain]

As far as I know, Burst doesn't like if or any other sort of logic splitting

[viral sonnet]

vectorization doesn't work with a conditional return

[rustic rain]

hm

I wonder if it's possible to write bool as int

and do loop where you simply constantly add to value a result of comparison

casted to int

[fickle smelt]

Yeah, I suspected as much 😦

[rustic rain]

Could you try it? xD

[fickle smelt]

Yeah, interesting theory. Just compiling ATM but will give it a go in a few minutes

[viral sonnet]

what maybe could work is if the ValidBiomes is bool4. but tbh, it's a bad application of simd

[fickle smelt]

I'll take a bad application of SIMD over a good application of scalar 😛

[viral sonnet]

and as you are struct comparing it would only work with an int4 hash or smth

[rustic rain]

    int kek = 0;
    for (var i = 0; i < ValidBiomes.Length; i++)
    {
        kek += (int) (ValidBiomes[i] == biome);
    }
    return (bool)kek;

Could that work? xD

[viral sonnet]

don't think so because you write to the same value

kek needs to be an array to work with simd

[rustic rain]

welp

unoptimizable

[fickle smelt]

It seems to have accepted this; (I can't paste as code as server keeps deleting messages for some reason);

int4 payload = new int4(0, 0, 0, 0);
for (var i = 0; i < ValidBiomes.Length; i++)
{
payload[i] = (ValidBiomes[i] == biome) ? 1 : 0;
}

return ((payload.x + payload.y + payload.z + payload.w) > 0);

Obviously that doesn't scale

[viral sonnet]

doesn't work but it's simd code 🙂

I'm always amazed how dumb simd code still is and how little progress CPUs have made. Maybe that's why apples M1 is so good, I dunno but having some kind of condition just break simd code is just dumb architecture.

[fickle smelt]

Yeah, I'm trying to update a poisson disk burst job I wrote that accepts a single biome as valid to accepting multiple valid biomes. But right now it's actually faster to just run a separate job for each valid biome.

I'm very green to SIMD (as I'm sure is obvious 😛 ) I might just give up on this one

[rustic rain]

Any idea whether LocalToWorld is being written every update or when there are changes to rot/translation/scale?

hmm, judging by source

it checks batch for changes

but does it already add to component version

simply by getting type handle

of LTW

or it only increases version after getting native array?

[solemn hollow]

Getting handle is not a problem. as soon as you call chunk.GetnativeArray(handle) on a not readonly handle you bump the change version.

[rustic rain]

So, that means ChangeVersion filter will work with LTW?

[solemn hollow]

havent tried it but seems like it should

ofc that is also depending on how you write to localtoworld and translation yourself

[rustic rain]

I only read ltw

only write to translation

or rotation

[solemn hollow]

if you declare write access on translation every frame then you trigger changes that will declare write access in localtoworld

which then bumps the version...

So you would need to be super careful on how to write to translations/rotations etc

if you only use Entities.Foreach(ref Translation t) just once you can already not use changefilter on localtoworld

[viral sonnet]

I made it a habit to call handles by their RW access. Translation_ReadHandle for example. Are all your handles read?

[viral sonnet]

ah, yeah then the version gets bumped

so your long DidChange if is always true

As there's only 1 version per chunk checking more than one comp is redundant

DidChange is next to unusable imo. Should be chunk version + comp version

[rustic rain]

Any idea what's wrong with this Camera drag script?
It works perfectly fine in mono

        private void OnCameraDragPress(InputAction.CallbackContext obj)
        {
            _dragging = true;
            _origin = _inputController.CursorWorldSpace;
        }

        private void OnCameraDragRelease(InputAction.CallbackContext obj) { _dragging = false; }


        protected override void OnUpdate()
        {
            if (_dragging)
            {
                var curPos = _inputController.CursorWorldSpace;
                var origin = _origin;
                Entities.WithAll<CurrentView>()
                    .ForEach((ref Translation translation, in LocalToWorld ltw) =>
                    {
                        var difference = curPos - ltw.Position;
                        translation.Value = origin - difference;
                        translation.Value.z = -10f;
                    })
                    .Schedule();
            }
        }

What happens is that when I try to drag and hold drag keybind

Camera starts to shake harder and harder with every second

hmmm, looks like this is why

world cursor position is constantly shaking, hmm

[rustic rain]

ah, looks I needed to do it in late sim system group

oh god

why tf is it eating 0.25 ms

ah, nvm. It was debug log

xD

[queen snow]

hey I want to use ECS for a bunch of features in my game, but I'm not sure where to start. Should I start by making prefabs and then converting them to entities via the prefab workflow or are there other options as to choice of workflow for developing the mechanics that use ECS?

[rustic rain]

for what features do you want to use ECS?

[cerulean pulsar]

if you haven't already, make sure you understand the fundamental concepts by reading the conceptual part of the manual: https://docs.unity3d.com/Packages/com.unity.entities@0.50/manual/ecs_core.html

[queen snow]

I want to store a bunch of lots, blocks, and buildings in memory for a city builder such that I can efficiently have a ton of buildings in a scene. The plan is to have a bunch of vertices that are just positions in 3D space and then have each city block or lot contain a list of the vertices by their index to define their shape in 3D space. or maybe use 2D polygon colliders for intersection detection in their trigger mode?

[queen snow]

Like I want to say to the engine "ok there is a specific entity archetype that has XYZ components called a plotVertex and I want you to create N amount of these here"

i guess this is OOP mindset

whats the difference between a runtime and an authoring component type

based on research, looks like I should use a dynamic buffer to store the data on which vertices are used for each city block or lot

[viral sonnet]

I'm a little confused. Like, what are you trying to solve? It sounds to me like efficient rendering. But that is pretty much solved with the hybrid renderer

[queen snow]

idk im kinda half thinking out loud here

[viral sonnet]

that's okay, just tackle one thing at a time. split your way how you think about the buildings, there are several parts here and none have much in common. data/game mechanics, collision/targeting, rendering

[viral sonnet]

Anyone got a NativeContainer working? I'm not sure what I'm missing other then the NativeContainer tag. It works fine from the main thread but when I use the container in a job the values are not written back.

Am I not allowed to use a NativeContainer inside a NativeContainer maybe? I have a NativeList instead of an UnsafeList

[rustic rain]

You can only have unsafe container inside native

[rotund token]

you can not

[rustic rain]

Are entities created during conversion in dstMansger valid?

[rustic rain]

Hmm.
I have this problem I am trying to solve, but so far I can't figure out a fine solution:
I need to create a planet trail, that will follow planet while it moves around star.
I decided to generate mesh for this trail, which I did. But turns out I need to also rotate this mesh correctly. And this rotation doesn't go along with planet's rotation.
Ok, so make trail entity separate. But here I go again. If that entity is parented on planet: it's rotation will be local to parent and thus, will be incorrect if I rotate planet. If that entity is not parented on planet -I'd need to do the calculations for position twice.

[rotund token]

what do you mean by valid?

they exist but they will have a different ID by time they're copied into game

[rustic rain]

it will continue to exist, in game world, right?

dstEntityManager

[rotund token]

dstEntityManager exists in a conversion world

[rustic rain]

so if I do dst.CreateEntity(archetype); will that be transfered into game world?

[rotund token]

hmm not certain on that

i think you need to use CreateAdditionalEntity

[rustic rain]

hmmm

so dst world is getting copied after conversion is over, huh?

that meaning

if I create 100 temporary archetypes in conversion world

they will cease to exist in actual world?

[rustic rain]

bruh, is there any reason why subscene in edit mode is about 50% times faster than closed subscene?

literally, 150 fps in edit
100 in closed

[solemn hollow]

check which systems are active in edit mode when closed

probably some transform system

[viral sonnet]

Unity.Entities.SystemBase:Update() (at Library\PackageCache\com.unity.entities@0.50.1-preview.2\Unity.Entities\SystemBase.cs:400)``` Gee, thanks. That's so helpful ... 🤣

[rustic rain]

hmm

looks same to me

ooooh

looks like it's related to lighting

I removed all light sources

and boom

even more fps

hmm

[rustic rain]

God damn it

Are lights even supported in subscenes?

Or even outside?

[rustic rain]

Is there a way to run loop on entities only once, each time they appear?
Basically, I have my systems with planets in subscene
But it appears, that subscene is loading only after actual system does OnStartRunning

So, once subscene is loaded, it doesn't get treatment of getting loop once

[pliant pike]

basic question but how do I use this NativeQueue<int2>.ParallelWriter indicesToCheck = new NativeQueue<int2>.ParallelWriter();

I presumed it was like this but indicesToCheck[nativeThreadIndex] it doesn't seem to work 😕

[rustic rain]

Doesn't it have Add method?

or smth similiar?

Enqueue

maybe

[pliant pike]

yeah all it has is an Enque method

I need the count, a deque and clear also

[rustic rain]

afaik, it's not safe in parallel

[pliant pike]

that's weird

[viral sonnet]

@pliant pike Where are you stuck? reading or writing?

[pliant pike]

either, both?

just need an example for how to use it, even if that doesn't work nativelist.parrallel will do

[rustic rain]

split your jobs

1 to fill your queue/list

through parallel writer

other to read info from it

[pliant pike]

thats what I did with a single thread queue but I need to do that with a parallel one now

[rustic rain]

in single thread you can read AND write

in parallel only either read or write, it seems

[pliant pike]

well that is just weird

[rustic rain]

well
having random access for reading doesn't seem too safe when you write to same memory in parallel

[pliant pike]

each thread should have its own separate queue though so should be fine surely

I mean I could set up separate queues manually if I really have to and put them into a schedule.paralell I guess

[viral sonnet]

you can safely write in parallel to the NativeQueue.ParallelWriter

I don't really understand where the problem is?

reading is with while(queue.Count > 0) var item = queue.Dequeue();

probably you want a NativeStream though. NativeQueue is pretty crappy

[pliant pike]

that does'n work for me I just get nativqueue.parallel writer does not contain a definition for count

is nativestream pretty much the same then

[viral sonnet]

the 2nd job just needs NativeQueue not the ParallelWriter one

it's pretty much the same, yeah, just writing/reading is faster and works better for parallel processing

[pliant pike]

so I'm guessing nativequeue.pararallel is just one long queue that works in multiple threads

[viral sonnet]

a nativequeue, parallel - every thread gets a memory block it writes to

[pliant pike]

that's not what I thought it was I'm sure we used to have a way to setup multiple arrays for parralell jobs

[viral sonnet]

hm? I don't understand. Anyway, the sucky thing about NativeQueue is that reading doesn't work in parallel, because there's no real, only reading, every read dequeues an item so a write is happening. I don't know, I don't like Queues 😄

one of the worst NativeContainers there is, they should just get rid of it imo

[pliant pike]

yeah that's what I'm thinking its probably not the best thing to use

I might just use a unsafelist with an nativelist in it if I can figure out how to get it to work

[viral sonnet]

it hardly has any use at all. It's pretty much superseded by NativeStream

NativeList sucks to write in parallel

[pliant pike]

how so

[viral sonnet]

the interlocked.add on the length causes thread stalling - you either allocate blocks or use a NativeStream

[pliant pike]

I guess I'll have a look at nativestream then thanks

[viral sonnet]

do you know how much items you'll write? then a pre-allocated array or list is your best bet with direct index access

[pliant pike]

yeah, I'm thinking I will just create an nativearray<unsafestream<int2>> or something like that and then use that in a ijobparralellfor

[viral sonnet]

huh? why wrap a nativeArray around the stream?

[rustic rain]

why don't just split jobs

so in one job you write, in other you read

[viral sonnet]

A NativeStream is built for that. No need to wrap it around another array

[pliant pike]

no worries I'll figure it out

[gusty comet]

I think this is the right place to ask but if not please let me know. I'd love some advice for this; I have a large amount of entities with some world position and I need an ideally very efficient way to do render a square quad (square in view space) for each of those entities such that the quad is facing the camera at all times and only scales with distance. Roughly similar to your average particle system really. (to be clear the entire thing is DOTS based so looking on pointers on how to efficiently get my little friends on the screen).

[rustic rain]

Quad rotation depends on what kind of rotation you are seeking.
For efficiency you could use gpu instancing

I actually did today a little system to draw quad as a line between two objects

Was kind of simple

With quaternion.lookrotation

[gusty comet]

Well I'm ideally seeking to avoid the rotation to begin with since my real need is essentially : world coordinate -> screen coordinate -> draw rect quad manually scaled by distance. To actually "physically" rotate each quad would require the engine to apply that rotation and then project the rotated quad to view space. That's significantly more work than is really needed for this case. I'd like some way to go :

• Get world pos W and project it to camera space C
• Determine distance from camera D
• Draw quad manually with the four vertices around C scaled by D

(for context, this is part of a simulation that ideally runs 100K-1M entities depending on hw)

[rustic rain]

Your quads have same rotation?

Btw with that large amount of entities to draw you'd better off use indirect instancing

[gusty comet]

Yes, same rotation, same material. They should all be facing the camera much like particles in your average particle system are billboard projected.

[rustic rain]

Well

Hm

[gusty comet]

And yes Graphics.DrawMeshInstancedIndirect or something is on my "probably this" list 😉

[rustic rain]

Are you having some sort of grid for quads?

Or position is vector based?

[gusty comet]

it's a float3

in world space

[rustic rain]

Hmm

Seems like a tough one

[gusty comet]

so the need is entity position (in world space) -> entity position (in screen space) -> manually draw rect around that screen position scaled by camera distance.

Is it? Isn't that essentially what every particle system with billboard rendering does?

[rustic rain]

You need to ship to gpu a large amount of data

Which will be a bottleneck

Huge bottleneck

[gusty comet]

Well my hope was just world coordinates and a projection matrix of some sort along with a vertex shader that does the billboarding.

It's easy to get 1m float3's to the gpu

[rustic rain]

You only need float3 per entity in this case

[gusty comet]

Right

[rustic rain]

1 million is a lot though

[gusty comet]

Well let's say 100k. This is one of those "more is better" situations.

[rustic rain]

Even 60k vector3 is a lot

[gusty comet]

It's a simulation where more simulated entities increases accuracy.

Okay. Hm.

[rustic rain]

You can try, but cpu gpu bandwidth is not that great

My approach was to ship index array

While position buffer wad kept on gpu all the time

And to get vertex position I just access that array with instance index

[gusty comet]

Hm. And positions were updated with a compute shader?

[rustic rain]

Not really compute

Normal shader

[gusty comet]

That would be hard(er) for me given the logic needed to update the positions.

Well, same difference I think right. Some GPU shader.

[rustic rain]

Vertex shader if I remember correctly

But since your positions aren't grid based

That approach doesn't seem to work

[gusty comet]

No it's conceptually similar to the Unity Boids example project in terms of needs.

[rustic rain]

And you even have more entities to draw xD

Anyways

[gusty comet]

There's relatively complex logic to update the positions, velocities and there's hit and collision detection needs.

[rustic rain]

I suggest just to try and do dumbest way possible

And see how it goes

Every other complex optimization will only make it better

[gusty comet]

I was just hoping the actual rendering would be easy enough. Maybe I was wrong. I was hoping the new pipeline would allow you to do some custom mesh rendering that would bypass the transformation and projection pipeline of Unity.

Yeah I guess.

[rustic rain]

Mesh rendering is same as in built in

At least api

It is quite simple tho

Until you need instancing

And then until you need indirect

xD

[gusty comet]

Which in this case would be a huge optimisation 😉

Since I literally just need exactly the same mesh rendered with exactly the same material and uvs.

Oh well. I'll puzzle along.

Thanks for your input.

[molten flame]

Dunno if I'm late to the party on this one but did you guys know V-Rising is made with DOTS?
If you haven't played it yet I very highly recommend it, especially if you loved Valheim.

[pliant pike]

really, that's cool, how do you know, and what did they use it for

[drowsy pagoda]

I got a weird bug. I wrote code for next version of my game. I ran tests in editor and it works without any issues. I went to Build it (using DOTS platform build, done it loads of times before, no issues). And it gives me a NullRef error when it was trying to run a static method.

I resolved the issue by making it avoid that method and saved the files, Unity refreshed and shows the changes were made when I open the script in the inspector. HOWEVER, when building, it gives me the same error as before referencing lines that no longer exist!

I trashed the build folder entirely, I restarted the editor and it still gives me the same issue, it's using some cached version of my script (before my changes). How can I flush this cache or where does the BuildConfiguration asset keep cached files?

Has anyone else had this before?

[viral sonnet]

never had this, maybe the good old deleting Library works. Which Burst version are you using? 1.7+ had weird caching problems

[drowsy pagoda]

I am using Burst 1.6.4. Yeah I was hoping to avoid nuking Library lol, but I suppose I have no choice. Gonna try it now.

[rotund token]

https://blog.stunlock.com/v-rising-dev-update-4-v-rising-engine-and-cutting-edge-technology/

they wrote it on their blog

[viral sonnet]

maybe don't nuke all, there are some Build* folders in Library. Start with those

[rotund token]

it just sounds like your code is being stripped

are you calling it indirectly?

(unless I'm misreading this)

[pliant pike]

thanks tertle, I'll totally read that, I knew dots was useful

[drowsy pagoda]

Yeah there were three, I backed them up, nuked them and still same error. I already nuked entire Library folder, building new one right now. Will let you know what happens once it's ready.

[viral sonnet]

@rotund token finally got the ArrayHashMap container working. now I can create a hashMap out of 2 arrays without abusing the NMHM 🙂

pretty cool, I needed source/target as keys and had the same value array and now it can be shared without maintaining a second (redundant) values array

[drowsy pagoda]

Nuking Library worked. I suspect something broke when I updated the editor to the next version.

[viral sonnet]

great! was it a minor version upgrade from 2020.3 or a bigger one?

[drowsy pagoda]

2020.3.33 -> 2020.3.34

[viral sonnet]

oh damn, I'll keep that in mind when I upgrade myself. still on .33

anyone able to figure this out: thrown when scheduling a CalculateBucketsJob. The system NZSpellCasting.HandleCombatEventsSystem reads NZSpellCasting.AvatarStatsBlobReference via CalculateSpellSystem:CalculateSpellJobFromNativeList but that type was not assigned to the Dependency property.

for some reason the calculateHandle is not respected

[rotund token]

are you writing it back to dependency?

(that complete is gross =D)

[viral sonnet]

this is the rest, I do set Dependency at the end

[rotund token]

what is sourcekeys

type

[viral sonnet]

NativeList

[rotund token]

yeah i think that's your problem

those AsArray

        {
#if ENABLE_UNITY_COLLECTIONS_CHECKS
            AtomicSafetyHandle.CheckGetSecondaryDataPointerAndThrow(m_Safety);```

if you cache the asarray before calculatespelljobfromnativelist

i think it'd be fine

or just pass them in as lists and cast in the job

though hmm

i thought that issue was fixed in collections that 0.50 uses

[viral sonnet]

Ok, solved it. I just rewrote the NativeArray to a NativeList in the job. I still don't get it.

well, at least I don't understand why the dependency safety has a problem with it. what I do understand is that the length in NativeArray would be copied by value so the previous calculate job would not increase the length unlike with a NativeList where the length is handled differently (in unmanaged space)

well, took a quick break which reminded me of the CheckGetSecondaryDataPointerAndThrow you mentioned. Guess this is really it. Pretty confusing error message though. 😄 Should just say so, and not tell me something about some random comp that isn't even used in the job that is scheduled.

[viral sonnet]

UnsafeArrayHashMap.cs(167,13): Burst error BC1020: Boxing a valuetype `Unity.Entities.Entity` to a managed object is not supported Wait, what? How does that work for every other NativeContainer?

[rotund token]

what is your line

[viral sonnet]

while (!(*(TKey*) (Keys + entryIdx * sizeof(TKey))).Equals(it.key))

odd, I have the same line in a hashmap extension that also uses Entity

(btw. you can congratulate me how unreadable that line is 😄 )

[rotund token]

your extension probably has IEquatable

this is why all the Find, IndexOf, etc methods

are in extension methods not the actual collection

[viral sonnet]

dayum, you are way too good at this.

yep, added IEquatable<TKey>. all fine now. thanks!

[white island]

What does this error mean?

[rotund token]

you're using a container in a parallel job without [ReadOnly]

[white island]

yeah i just figured that out, testing my solution

wait, what. What container does it want

[viral sonnet]

I really dislike the implementation of ContainsKey in NHM. It reads and outs the value which is unneeded

[white island]

how can I tell which container is bad?

is it a nativelist

[viral sonnet]

the errors mentioned tree.nodes

[rotund token]

it tells you in the error - what enzi said

[white island]

ah, ok. the errors are hard for my brain to parse...

ok, so it's a nativelist. I can't mark it as readonly though, because I write to it a bit, but before I start the job

[viral sonnet]

you get used to them after reading them a 1000 times 😄

then you have to use NativeList.ParallelWriter instead of your NativeList

ah before you start the job. hm

then readonly is okay? the statement is confusing

you either write to it in the job or not 🙂

[white island]

I don't need to write anything in the job

the struct is passed in as a paramenter

in the job, the paramenter is declared as

[ReadOnly]
            public KDTree.KDTree tree;

[viral sonnet]

and the nodes in tree?

[white island]

nope. ok using the [ReadOnly] attribute fixed that. But now a hashmap in the system needs to be declared readonly, but i'm not 100% sure how to do that in this way

[viral sonnet]

what's different? you can put the [ReadOnly] in the same way there

[white island]

in the OnUpdate function?

it says it's not valid in this context

[viral sonnet]

is the hashmap a parameter in the job or not?

[white island]

no it isnt

it's for the entities foreach

which i guess is a job actually

[viral sonnet]

in a forEach you can declare .WithReadOnly(yourHashmapVariable)

[white island]

where? where I read it? intellisense doesn't give me anything like that

[viral sonnet]

Entities.WithReadOnly().ForEach().Schedule();

[white island]

okay, cool. should I use an entity command buffer for parallel writing instead of just the entity manager?

[viral sonnet]

yeah, it's a good habit

using entity manager creates structural changes on pretty much anything create/destroy/set/remove

private EndSimulationEntityCommandBufferSystem endBarrier;

in OnCreate: endBarrier = World.GetOrCreateSystem<EndSimulationEntityCommandBufferSystem>(); 

in OnUpdate: var commandBuffer = endBarrier.CreateCommandBuffer(); 

in job: commandBuffer = commandBuffer.AsParallelWriter() 

after schedule: endBarrier.AddJobHandleForProducer(Dependency);

when you use it in a ForEach you could just write: var commandBuffer = endBarrier.CreateCommandBuffer().AsParallelWriter();

as the commandBuffer in parallel needs an index, either int nativeThreadIndex or int entityInQueryIndex works as input parameter in the ForEach parameter list

[white island]

that was my next question

can an ECB get a buffer? It says EntityManager.getBuffer causes a write

[viral sonnet]

you can AppendToBuffer with an ecb

[white island]

yeah but i need to read the buffer's length

[viral sonnet]

is the buffer on the entity?

[white island]

yes

[viral sonnet]

then use it as an input

[white island]

like use DynamicBuffer<foo> bar in the argument list?

[viral sonnet]

yes

it has a certain order, in and ref parameters are behind it

[white island]

boy howdy. the hydra of errors here. Never heard of dependencies here, what does this error mean?

[viral sonnet]

get used to it with scheduling 🙂 means data that you want to access is written to by another job and you have not set a dependency to it

have you just forgotten to set the Dependency? Dependency = Entities.ForEach().Schedule(Dependency);

if it still doesn't work you have to get the jobhandle from the MobOffScreenMovementSystem and use it as dependency handle for your job

[white island]

well, I'm using a .ScheduleParallel() so that everything runs in parallel

[viral sonnet]

that much was clear 🙂 do you really have to split the 2 jobs in 2 systems? would be easier if you schedule them from just one because then you have the handle immediately.

[white island]

what do you mean by that

[viral sonnet]

going back to that: means data that you want to access is written to by another job and you have not set a dependency to it

which also means, the 2nd job doesn't wait for the first one to complete

the job system doesn't figure that out automatically

apparently it should but it never does for me so I'm at a point where I think it's pretty dumb and doesn't figure anything out on its own 😄

here's how I do it when more than 1 system is involved

you don't have to Complete the handle, in your case just use the handle instead of ScheduleParallel(Dependency)

[white island]

that doesn't make any sense. No jobs set the dependency it's complaining about

in fact it's listed as in in the foreach

[viral sonnet]

look at the stacktrace and where it's thrown

is it a line where a schedule happens?

[white island]

yes, thats the wscheduleparallel

[viral sonnet]

yeah, then that's what it is 🙂 I've had my fair share of grief with the error messages. the important bits are where it's thrown so you know which job is missing the dependency and the mentioned job so you know which dependency you have to set

either way, in one job you are writing to InSceneComponent

[white island]

wait. it's the ecb playback

not the schedule

[viral sonnet]

huh? do you use playback?

do you have this line after the schedule? endBarrier.AddJobHandleForProducer(Dependency);

[white island]

yeah, I define an entity command buffer like so:

EntityManager em = EntityManager;
            EntityCommandBuffer ecb = new EntityCommandBuffer(Allocator.TempJob);
            var ecbp = ecb.AsParallelWriter();

and then after the foreach where I use ecbp, I call

ecb.Playback(em);

[viral sonnet]

well, that's no good. I posted the code :/

that breaks scheduling

a commandbuffer should run at the end of a frame when all is finished

with the code you used it's running in the middle of it and creates structural changes which breaks any schedule that happened so far

[white island]

I thought the end barrier was a custom class

[white island]

yeah, the playback runs after foreach

[viral sonnet]

that's just the variable name. everyone has EndSimulationEntityCommandBufferSystem

after foreach != end of frame 🙂

you can copy/paste what I wrote above #archived-dots message

[white island]

what is Dependency

[viral sonnet]

a SystemBase variable. every SystemBase has it

[white island]

Do I play this back now?

[viral sonnet]

no, that's done for you

by the EndSimulationEntityCommandBufferSystem

[white island]

do I need to dispose the entity command buffer and parallelwriter?

[viral sonnet]

no

heading off now. good night all o/

[rustic rain]

wtf

I am trying to Add rendering components

[rotund token]

what are you doing 🧐

[rustic rain]

                var meshRenderer = GetComponent<MeshRenderer>();
                var desc = new RenderMeshDescription(
                    GetComponent<MeshFilter>().sharedMesh,
                    meshRenderer.sharedMaterial,
                    meshRenderer.shadowCastingMode,
                    meshRenderer.receiveShadows,
                    meshRenderer.motionVectorGenerationMode,
                    gameObject.layer,
                    meshRenderer.subMeshStartIndex,
                    meshRenderer.renderingLayerMask
                );
                RenderMeshUtility.AddComponents(renderingEntity, dstManager, desc);

in authoring mono

[rotund token]

ah why not just let it do its own thing?

[rustic rain]

I need renderer outside of main entity

and I don't want to have complex authoring

so far I managed to achieve this with trail system

but classic Render mesh seems to fail me

[gusty comet]

Hi... What libraries do I need to install to start working with dots...

[rustic rain]

just install Hybrid Renderer, it will install all necessities itself

Turns out, error is caused when I remove rendering components from original entity

                {
                    dstManager.RemoveComponent<WorldRenderBounds>(entity);
                    dstManager.RemoveComponent<RenderBounds>(entity);
                    dstManager.RemoveComponent<RenderMesh>(entity);
                    dstManager.RemoveComponent<PerInstanceCullingTag>(entity);
                    dstManager.RemoveComponent<BlendProbeTag>(entity);
                }

hm

[gusty comet]

@rustic rain thanjs5... Can I also ask one question... Do you know if I can use a character controller in the dots system?

[rotund token]

feel like you've left a bunch components behind on that removal

what does the remaining archetype look like?

[rustic rain]

idk, it errors

so it doesn't even finish removing

turns out

it errors on removing RenderMesh

only

no need for anything else

OOOOH

it's Shared

me dum dum

hmm, no different method for shared components

[rustic rain]

no, you need to write/buy/find one yourself

classic unity components don't exist in ECS world

and hybrid approach is dogshit IMO

[gusty comet]

I see @rustic rain thank you

[rotund token]

yeah was about to say, it should make no difference

[rustic rain]

well, it errors

even if I remove other componnets only

wtf

I'll restart Unity

lol, it errors even during non-play authoring

https://forum.unity.com/threads/how-to-properly-disable-rendering-on-entity.1024585/

Seems like this problem is from 2020

oof

[honest plinth]

Yeah removing the RenderMesh component is not a good idea. You want to add the DisableRendering component instead.
Also RenderMesh component will go away in the near future as we move to use the new BRG interfaces where we can use different meshes and materials within a single chunk

[rustic rain]

I have a problem with DisableRendering since it's key component for my rendering systems

seems like I'll need to implement some other tag to fix it for a while

feels bad

hmm

or maybe I can simply remove entity

and create new

xD

[honest plinth]

Hm... Yeah sorry I'm not of much help here :/
What is it that you are trying to do?

[rustic rain]

Move rendering to child entity

while authoring through 1 game object

since I'll need a ton of prefabs, which will make it a nightmare if I'll have to keep it 1 to 1 in gameobject/entity ratio

moving rendering is important, cause I will need specific rotation for this rendering, while keeping hierarchy intact

[rustic rain]

bruh

doesn't seem possible

allthough...

[gusty comet]

can we work with normal game objects and entities at the same time? like have a character controller and lots of other game objects that have entities ?

[rustic rain]

Entities world and Game Object world work separately

communication between two is not recommended

[pliant pike]

yeah I've done that

[rustic rain]

but if you want to

it's possible

[pliant pike]

there's also a unity gdc talk I think where they explain how they do it

its not as hard as you'd think

[gusty comet]

can you give me the link please

[pliant pike]

I can't find it I'm afraid

[cerulean pulsar]

This is called a "hybrid" setup. You can access ECS data from a MonoBehaviour with World.All[0].EntityManager.GetComponentData, for example. And you can access GameObject data from a System normally, like mainCamera.transform. You can get a reference with mainCamera = GameObject.Find("Main Camera") for example

[gusty comet]

it's ok , thank you for helping

[gusty comet]

I see thank you

[rustic rain]

oh man, because of inability to remove RenderMesh

I literally can't finish my mechanic

xD

now I can't wait for 1.0 10x more

[cerulean pulsar]

what's an example of needing to do this? Perhaps without revealing your mechanic if it's secret

[rustic rain]

I need to move rendering components to child entity, without making authoring be a pain

cause the other way I can do it: make child game object, put all rendering here

PAIN

every time I'll select object, it'll pick child and etc

[cerulean pulsar]

Maybe you can write an editor script that selects the parent of a selected GameObject when it has a certain GameObject component (e.g. some empty MonoBehaviour serving as a tag for your editor script)

[rustic rain]

that still makes creation of prefabs painful

[cerulean pulsar]

What is this second pain? Maybe there's a way to automate it away, too

[rustic rain]

welp, that's what I wanted: automate it

what i want: put components on GO, components do all the job themselves

but instead I have to create hierarchy of those children in gameobject myself

since I can't remove rendering components from main entity

which will be parent for all children

[cerulean pulsar]

During conversion, maybe you can move the MeshRenderer to the child before the hybrid renderer converts it to a RenderMesh. (But maybe I'm not understanding the problem yet)

[rustic rain]

hm

[cerulean pulsar]

Via a custom conversion system

[rustic rain]

I see

eh, still tweaking with game objects

instead of doing whatever I want in entites world

sadge

but that's a plan

at least

[cerulean pulsar]

I think writing custom conversion systems will be a skill that will pay boons for years, because as far as I know the Unity DOTS team believes in conversion from GameObjects as authoring data to Entities as runtime data as a fundamentally good thing

"It is a fundamental part of DOTS, and not something temporary" https://docs.unity3d.com/Packages/com.unity.entities@0.50/manual/conversion.html

[rustic rain]

I already work in custom conversion systems kek

I just didn't think of option

to actually move GO components before entities are created

[solemn hollow]

i cant share details here but i saw a major AA title (made with unity) rolling their own conversion pipeline to reduce loadtimes, memoryfootprint, complexity and guarantee good authoring workflows for designers. It seemed like their whole toolchain was built around this conversion too.
DOTS Conversion does all that and enables easy runtime performance gains through better memory layout too. I really like the decision to make Hybrid & Conversion the standard workflow (even though i personally go "pure" as much as possible).

[rustic rain]

Is it possible to get entity query in authoring component and run ForEach loop inside?

in dstWorld

during conversion

I am trying to implement world gen this way

[solemn hollow]

not sure what you want. what stops you from using conversionsystems?

and you should not run queries on dstWorld but only on Conversionworld while converting

[rustic rain]

not sure rn what approach even to use.
Basically I have a choice between:

1. Fully generated world
2. Premade world, but with randomized positions and stats

[solemn hollow]

in either case you can use conversionsystems to create the world i think

but there is one huge downside if you fully generate the world. You cant use EntityManager.Instantiate in Conversion... So its a PITA to spawn entites... Honestly i would probably generate the world with GameObjects first in early conversion and then convert all the generated objects to entites.

And you need to be aware that conversion runs everytime you close a subscene

[rustic rain]

if I generate GO world in early

[solemn hollow]

so you want a deterministic way of generating the world

[rustic rain]

that means all of them will be converted as if I author them before pressing RUn?

[solemn hollow]

i hope so. i cant guarantee it

from docs : [GameObjectDeclareReferencedObjectsGroup] - before the creation of entities in the destination world.

so as i would understand it if you instantiated gameonjects during this step it would be the same as if you hand authored it

[rustic rain]

btw, how do I get dependency from casual loop?

            var pos = Entities.WithAll<StarSystem.StarSystem>()
                .ForEach(() =>
                {
                    
                })
                .Schedule(new JobHandle());

will that work?

[solemn hollow]

the dependency is resolved through passing jobhandles. im not sure about that new JobHandle there. you tell this Job to wait until a new Jobhandle is completed (which should be never).

what are you trying to achieve here

[rustic rain]

I need to get dependency

from scheduled job

[solemn hollow]

yes that is what "pos" is

[rustic rain]

Basically I have job X, Y and Z.
Y requires X and Z to complete, while X and Z can run independent.

and job above is X

while Z is var count = _starSystemQuery.ToEntityArrayAsync(Allocator.TempJob, out var dep);

which gives me jobHandle itself

[solemn hollow]

so you need to pass dep into the .Schedule() of the other jobs so they wait for it

sry reading it again you only want Y to wait. so it should be in Y

[rustic rain]

well yeah, but how do I get job handle from job X

so I can pass it as dependency into job Y

[solemn hollow]

var jobhandleX = jobX.Schedule()

[rustic rain]

if I leave parameters empty it returns void

[solemn hollow]

rly? in that case you'd need to pass Systems Dependency

var jobhandleX = jobX.Schedule(Dependency)

[rustic rain]

oh

I see

[solemn hollow]

but sounds weird. i thought if you leave the paramenter empty is automatically uses Systems Dependency