10
votes
Accepted
Dealing with more complex entities in an ECS architecture
Games typically approach this type of issue using a transformation hierarchy.
In this model, each entity can be treated as a "child" of a "parent" entity. The entity's local ...
- 141k
5
votes
Accepted
Appropriate Cache Friendly Associative Container For An Entity Component System
Do the simplest thing that works, especially early on.
If you've ever seen videos of triple-A titles in alpha, you'll know how slow / buggy they are. This is normal; in fact, it's desirable. And it's ...
- 30.4k
5
votes
Accepted
How to implement n-body in an Entity Component System
One nice thing about systems in an ECS architecture is that they don't all necessarily need to follow the same structure of ...
- 123k
5
votes
Accepted
Should entities auto-register to systems based on their component signature?
TL;DR Entities SHOULD NOT auto-register to systems based on component signatures; prefer instead to explicitly declare component sets/nodes to register your entities to systems that operate on ...
4
votes
Accepted
ECS component dependencies / sharing and cache locality
Reducing cache misses doesn't need to mean getting rid of them entirely, so we do need to be wary of "making the perfect the enemy of the good enough"
After all, the absolute worst performance your ...
- 141k
3
votes
How to Implement ECS Archetypes in C#?
Here is a sketch of how you can implement an archetype in C#:
...
- 141k
3
votes
Accepted
Implementation details of Command Pattern in conjunction with Entity Component System
How do I populate the execute command if there isn't any logic that
"belongs" to an entity?
But there is a mechanism for applying logic to an entity: Systems. In ECS, Systems map behavior to ...
- 408
2
votes
How to handle Entity Initialisation and Destruction
This is one of the common problems with ECS architecture: Intersystem communication.
There is no silver bullet solution, and research is ongoing, but common solutions are:
Observer patterns. Any ...
- 2,694
2
votes
Entity Component System: system and components relation
My point is: if the Systems are the ones responsible for the actual
game logic update (practically speaking, the game logic code is
written inside the system), is there a 1:1 relation between ...
- 490
2
votes
Pass data down to components
Will you have networking?
I understand that you are probably making a single player game engine. However, thinking about how to deal with the network very, very, very early in the desgin will push ...
- 28.2k
2
votes
Accepted
Event-Based Entity-Componenty-System
Entity movement is a great example.
In most games, they do not care what triggers the movement, only that entities move in a common and standardized way. So the idea is to design some middle-man ...
- 2,022
2
votes
Appropriate Cache Friendly Associative Container For An Entity Component System
ArcaneEngineer's advice is good, particularly for early development (to an extent - once you configure your engine to work a particular way, it can be significantly hard to rework it later).
For ...
- 148
2
votes
Accepted
Where should I put units and items in a squad-combat ECS-based game?
As a general disclaimer and as DMGregory already stated it: The rules of ECS are not written in stone. Doing it on way has benefits, doing it another way has some others. So, you need to know, what ...
- 1,332
2
votes
Accepted
How to Implement ECS Archetypes in C#?
Those Archetypes are IEnumerable<TComponentKind>, where TComponentKind is what you use to identify components. You can, of ...
- 28.2k
2
votes
Implementations for storing entities in an ECS system
Neither of the three approaches are typical. The first approach could be considered a "naive" approach as it works, but is not very efficient because you'd need to check for every entity if it matches ...
- 193
1
vote
Accepted
How do I contiguously store and iterate over ECS components in C++?
Entity component systems store data in one of three ways:
Centrally allocated arrays, accessable by all systems.
Contigious arrays of subsets of components that each system is interested in.
...
- 2,694
1
vote
Accepted
How do you handle entity life-time and entities without all components in an ECS?
One way this can be solved is with the notion of Archetype.
An Archetype is the set of components a particular entity needs. So in your example you have two archetypes: (position, velocity, visible) ...
- 141k
1
vote
Hidden copies of the environment in an entity component system
I presume since you want a system similar to Entt you're writing in C++.
Environment Rendering
One of the simplest solutions you may find for the rendering system would be a simple boolean property on ...
- 11
1
vote
Additional Entity ID for networking instead of general EID?
An UUID takes up 128 bits.
Your own ID can be as small as ceil(log_2(n)) bits; where n is the number of entities you want to distinguish between.
Getting the ...
- 8,112
1
vote
How could I get rid of these shared_ptr/weak_ptr in this entity-component architecture?
If there is a single owner and you can properly handle clearing dangling pointer it is fine to use unique_ptr for the owner and raw pointers for the non-owners.
...
- 8,112
1
vote
Accepted
Implementations for storing entities in an ECS system
Sander's answer mentioned families, and I wanted to add some info:
Families group entities together based on component criterion.
Usually, a system has one family that forms its entity list.
...
- 408
1
vote
How to implement n-body in an Entity Component System
For every matching entity, Gravity will have to walk over all the
entities (minus one) to compute the attraction force. The first
problem is, how do I efficiently get the relevant entities? A ...
- 1,332
1
vote
Use GKEntity's component(ofType:) with inheritance
Well it appears as if no one here seems to know it so I'll just post what I used which is a new method that I added in an extension to GKEntity (which I was ...
- 151
1
vote
Accepted
How to: Duplicating and updating component data in systems
First of all, there is no such thing as a good pure ECS. Every ECS system is different, and all of them have their own advantages and disadvantages.
Problem #1
I'd go with the following setup. ...
- 201
1
vote
Event-Based Entity-Componenty-System
As Naro's said, you need a component for every player, that joins a Guild / Party / Alliance to save the information, that they are in that alliance or whatever.
But you most likely need a serverside ...
- 1,332
1
vote
How does an ECS work for a world subdivided into chunks (example)?
This answer is focused on how I would approach solving the problem instead of a prebaked specific answer.
For google reference, the basic ideas are based on broad phase and narrow phase collision ...
- 146
1
vote
Accepted
Entity Component System data duplicate
When you have a large amount of data shared between multiple game entities, then the component representing that data might be a good candidate for the flyweight pattern. Your ...
- 123k
Only top scored, non community-wiki answers of a minimum length are eligible