Broad Phase Query

[near fjord]

Is using GetPartBoundsInRadius a good way to filter out possible entities for your detection system?

[wheat glen]

that's a spatial query not a filter

and while yeah you can filter within the query, i don't think that's what you were asking - actually, i'm not sure what you're asking

can you elaborate what you mean by detection system

[still karma]

I'm not entirely sure what your asking

GetPartBoundsInRadius makes use of the same logic the physics solver uses, including however broad phase is handled, so its reasonably performant most of the time.

I don't know enough to say if GetPartBoundsInRadius is strictly good or bad for your situation, it depends.

If the performance is good, it might be a fine solution.
Keep in mind I don't know what your doing, so even an O(n^2) search of everything might be faster, it depends.

[near fjord]

That's actually what I'm asking, I'm using a magnitude check for my hit detection and was wondering whether I could use a spacial query to act as a filter

[near fjord]

I'm using the spacial query to filter out the positions needed for my magnitude hitbox checks

[still karma]

Whats the total number of magnitude checks you'd have to do if you didn't use a spatial query?

[near fjord]

Around 80

[still karma]

tbh you can almost certainly get away with just doing the magnitude checks

it will probably be faster anyway

[wheat glen]

spatial query is almost always faster than checking against an array of instances

it depends how big the array is

and how often

[wheat glen]

i'd consider spatial query to be more optimal at this scale

it scales better

[near fjord]

I'm doing them every 0.04 seconds for around 0.1-0.3 seconds depending on my active frames

[near fjord]

Yeah I was hoping it would work as a filter so I can get better performance

[still karma]

yeah computers are fast as fuck I would just leave it with magnitude checks

you can always optimize it later if it becomes a problem

[near fjord]

Which one scales better though?

[still karma]

also, consider doing a squared distance check instead of magnitude

[still karma]

spatial query but I disagree with pyro on where the line is of one being better than the other

[near fjord]

You think it'll be fine per m1 because assuming we have 20 players (and 80 entities overall) that's around 1600 checks assuming they all m1 per second

[still karma]

*though asterisk because if you have of thousands of parts around that don't need to be queried, they will still be taken into account by the spatial query which can heavily hinder performance. You can get around that with world models but it does make stuff more complicated

[wheat glen]

sqrt is most expensive part of it

[still karma]

yeah

also, consider doing a squared distance check instead of magnitude

[still karma]

yeah thats fine

especially if you do your own distance check that doesn't use square root

and compares squared distances

will be fast as fuck

[near fjord]

So you think it'd be better to do a squared distance check over a spatial query?

[still karma]

For your situation, absolutely

[wheat glen]

i'd still go for spatial query

magnitude checks lack accuracy

[still karma]

@near fjord Go with whichever one you will have an easier time implementing. If it ends up being too slow, try implementing the other one

[near fjord]

Thanks guys

I'll stick with the query for now but I'll look into squared checks if performance becomes an issue

[near fjord]

I know that I got my answer but I just forgot to mention that I use a whitelist for the spacial query. I wonder if that changes your view on things.

[still karma]

The spatial query (same with raycasts and everything else like that) will query every object in the world model and then filter those resulting matches based on your whitelist

So performance is actually technically worse when using a whitelist/blacklist 😭
-# though not a reason to avoid using the whitelist, because if you do, you'd probably end up doing the same thing but in luau

If you want to actually limit what a spatial query/raycast queries against, place the parts you want to query inside a world model and use its query methods
https://create.roblox.com/docs/reference/engine/classes/WorldModel

[near fjord]

Gotcha that changes things for me

[near fjord]

Ok tysm

[near fjord]

Will placing characters into a world model have any effects on behavior?

[wheat glen]

first i'm hearing about this, always thought model and worldmodel were the same

the more you know

ikmoveto looks interesting i wonder why plugin only

[still karma]

They will stop simulating physics

and won't collide with anything in the workspace or other world models

If you wanted to use them, you'd have to add a part to the world model for each target and then query those.
Every frame, update those parts to match the position of the target in the workspace
When you do the query, map the matched parts to their corresponding targets

[spring kernel]

** You are now Level 29! **

[near fjord]

sounds like a lot more work than just doing a squared broad check 😅