Conditional Query?

Unity Engine
,
1

For example:
I have a game where 100000000 black flys live in the forest. Normally each fly sits and does nothing, but if there is a man is in the forest, all flys should start following him and try to bite him.

So I need a system that does 2 things:

  • check if man exists (query for the entity with [man] component and its [position])
  • and if the man was found iterates on all flys and call MoveTowards(man.position) function

the problem is with “if”, how to make a conditional query?
if the man isn’t in the forest, the second costly query should not happen

Best idea I have is to split it into 2 systems: CheckForManSystem and MoveFlysSystem
and to make CheckForManSystem enable/disable MoveFlysSystem

What is the best way to organize this behavior in ECS?
Is it possible to skip the second query using only one system?

2

Why complicate it, single system with a requirement on the man query to run

this.RequireForUpdate(manQuery);

or

this.RequireSingletonForUpdate();

if there is only ever a maximum of 1 man.

2 Likes
3

wow, I’ve missed a moment when RequireForUpdate and singleton methods were added

4

Perfect, thank you, works like a charm )

1 Like