[jeremycw]

I think the focus on ECS when talking about data-oriented design largely misses the point of what data-oriented design is all about. Focusing on a _code_ design pattern is the antithesis of _data_-oriented design. Data-oriented is about breaking away from the obsession with taxonomy, abstraction and world-modeling and moving towards the understanding that all software problems are data transformation problems.

It's that all games essentially (and most software in general) boil down to: transform(input, current_state) -> output, new_state

Then, for some finite set of platforms and hardware there will be an optimal transform to accomplish this and it is our job as engineers to make "the code" approach this optimal transform.

[bob1029]

> Data-oriented is about breaking away from the obsession with taxonomy, abstraction and world-modeling

Something about this does not sit well with me.

Data is absolutely worthless if it generated on top of a garbage schema. Having poor modeling is catastrophic to any complex software project, and will be the root of all evil downstream.

In my view, the principal reason people hate SQL is because no one took the time to "build the world" and consult with the business experts to verify if their model was well-aligned with reality (i.e. the schema is a dumpster fire). As a consequence, recursive queries and other abominations are required to obtain meaningful business insights. If you took the time to listen to the business explain the complex journey that - for instance - user email addresses went down, you may have decided to model them in their own table rather than as a dumb string fact on the Customers table with zero historization potential.

Imagine if you could go back in time and undo all those little fuck ups in your schemas. With the power of experience and planning ahead, you can do the 2nd best thing.

[jeremycw]

You're right, when I mentioned "taxonomy, abstraction and world-modeling" I meant as it pertains to code organization in the tradition OOP/OOD sense where it's generally about naming classes, creating inheritance hierarchies, etc. Data-oriented design is _absolutely_ concerned with the data schema. I would, however, disagree that the focus should be on "building the world" with your schema. To me this means creating the schema based off of some gut/fuzzy feeling you get when the names of things all end up being real world nouns. To me creating a good schema is less about world building than it is about having the exact data that you need, well normalized and in a format that works well with the algorithm you want to apply to it.

[zarkov99]

People love SQL because it is truly an incredibly bad language. Poor to no ability to abstract, no composability, a grammar so convoluted it makes C++ look logical, and so on. The relational model is a beautiful thing but its power is obscured by how awful the main gateway to it is.

[typon]

Schema design is THE problem data oriented programming is focused on. It's saying, let's design our data structures in memory and on disk such that they exist to solve the problem at hand. I think youre talking about the same thing

[dragonwriter]

> moving towards the understanding that all software problems are data transformation problems.

But this understanding is fundamentally, deeply wrong, in the same way that civil engineering based approaches to software engineering are wrong for most software applications.

That is: yes, all software systems are data transformation systems, but most software problems are not “how do I produce the system most narrowly tailored to the present requirements” but more often “how to engineer a system for success with the pace and kind of change that we can expect over time in this space”.

(Now, games, particularly, are both pushing the limits of hardware and fairly static, so making them narrowly-tailored, poorly adaptable static works is often not wrong. But that doesn't generalize to all, or even most, software.)

[sitkack]

That is how you think about the software you write. System evolution is only one aspect. Most patterned OO codebases I have come across were *not* engineered for evolution. Sure there were some classes you could implement or replace, but the complexity was not paid back later.

Design principles can be applied to all implementation mechanisms.

[WorldMaker]

This fits my gut feeling every time I see an ECS system that videogame design has gotten stuck in a local maxima abstraction/pattern. Often what they really want is a Monadic abstraction of a data/state transformation process, but they are often stuck in languages ("for performance reasons") that make it hard to impossible to get good Monadic abstractions. So instead they use the hammers that to make nails of the abstractions that they can get. ECS feels to me like a strange attempt to build Self-like OO dynamic prototypes in a class-based OO language, and that's almost exactly what you would expect for an industry only just now taking baby steps outside of C/C++.

C# has some good tools to head towards that direction (async/await is a powerful Monadic transformer, for instance; it's not a generic enough transformer on its own of course, but an interesting start), but as this article points out most videogames work in C# today still has to keep the back foot in C/C++ land at all times and C/C++ mentalities are still going to clip the wings of abstraction work.

(ETA: Local maxima are still useful of course! Just that I'd like to point out that they can also be a trap.)

[learc83]

>"for performance reasons"

The quotes imply that this is a bad reason, but in soft realtime systems you often want complete control of memory allocation.

Even in the case of something like Unity--in order to give developers the performance they want--they've designed subset of C# they call high performance C# where memory is manually allocated.

In most cases if you're using an ECS, it's because you care so much about performance that you want to organize most of your data around cache locality. If you don't care about performance, something like the classic Unity Game Object component architecture is a lot easier to work with.

[BobbyJo]

> Focusing on a _code_ design pattern is the antithesis of _data_-oriented design

Doesn't the former enable the latter? Ideally, language (both human and machine) would have the semantics needed to represent all transforms, but that's not the case. Code you rely on, since none of it is written in isolation, needs to enable you to implement data-oriented design should you so choose.

Also, I don't think pointing out that 'all games are essentially...' is particularly useful. It's true, no question, but that doesn't mean it's the most useful mental model for people to use when developing software. Our job as engineers is to make software that functions according to some set of desires, and those desires may directly conflict with approaching an optimal transform.

[jeremycw]

> Doesn't the former enable the latter?

Not necessarily. ECS is a local maxima when developing a general purpose game engine. Since it's general purpose it can do nothing more than provide a lowest common denominator interface that can be used to make any game. If you are building a game from scratch why would you limit yourself to a lowest common denominator interface when there's no need? Just write the exact concrete code that needs to be there to solve the problem.

> Our job as engineers is to make software that functions according to some set of desires, and those desires may directly conflict with approaching an optimal transform.

All runtime desires of the software must be encoded in the transform. So no software functionality should get in the way of approaching the optimal transform. What does get in the way of approaching the optimal transform is code organization, architecture and abstraction that is non-essential to performing the transform.

[typon]

It's really annoying how many people misunderstand the term 'data oriented design'. Usually to mean something like 'not object oriented programming'. If your data was inherently hierarchical and talking about animals that meow or moo, go ahead and implement the textbook OO modeling.

This Mike Acton post describes it accurately: http://www.macton.ninja/home/onwhydodisntamodellingapproacha...

[nikki93]

I do think that in practice a hierarchical ontology like that is still best not modeled as a language-level hierarchy because the language inheritance / hierarchy concepts are often not the exact semantic you want, IME. Esp. if it then ties to static types, since you then can't change the hierarchy at runtime. I think even with a data-oriented approach to a hierarchy -- your code isn't necessarily hierarchically organized, it just handles data that happens to express a hierarchy. And you want to be in control of the semantics of said hierarchy with more freedom (and explicitness) than the language-level hierarchy gives you -- so you want your own code that interprets the hierarchy expressed in the data and performs your desired semantics. This also allows artists and narrative or gameplay / level designers to go see and edit the hierarchy and add elements to it.

An example is the prefab hierarchy you get in Unity, which is expressed through the data (prefabs and their relationships). (Note: I mean specifically the prefab inheritance hierarchy, not the transform spatial hierarchy -- the former has more overlap with the "is a" relationships). The code processing this hierarchy could've just been plain C code that parses the files and maintains an in-memory set of structures about them, even. You then get to define how properties inherit, what overriding means, etc. yourself.