How is this animation preloading?

[SelDraken]

Here is a bit of code from the default Animate script for a character.

	-- preload anims
	for i, animType in pairs(animTable) do
		for idx = 1, animType.count, 1 do
			if PreloadedAnims[animType[idx].anim.AnimationId] == nil then
				Humanoid:LoadAnimation(animType[idx].anim)
				PreloadedAnims[animType[idx].anim.AnimationId] = true
			end				
		end
	end

I am curious, as to how this is actually preloading the animations?
The part Humanoid:LoadAnimaion() should be returning a track, right?

And since we are not storing the return value, does that mean the track will get GC’d at the end of this function?

Also, considering that elsewhere in the code, tracks are :Destroy(), does that instead mean the tracks are held up in memory somewhere, until the entire script is GC’d?

Thanks for any insight into this.

[PhoenixRessusection (PhoenixCausesOof)]

Make __gc work on tables - #2 por Kampfkarren - Engine Features - DevForum | Roblox

It probably will be.

Edit:

@OptimistKnight

Yes, all objects, such as instances, tables, functions, coroutines, userdata, etc. are eventually going to get garbage collected as long as reference by the time of garbage collection is lost, or object is weakly referenced (look into weak tables).

Garbage collection in Roblox doesn’t happen instantly, as that would represent a huge amount of resources wasted, hence it runs perhaps periodically as well, but more notably, on demand. You can trigger garbage collection by creating a lot of instances/data and deleting them right after.

EDIT.
Here’s an example of how we can confirm garbage collection was successful. I used @Anaminus’ line from another post that is a very handy way to activate the collector (thanks!).

task.wait(3) -- Looks like GC is active when game starts, so we'll wait a little.

local storage = setmetatable({},{__mode = "v"}) -- weak table values

do -- Reference is lost once out of scope.
	local watchedObject = Instance.new("Part") -- not parented anywhere
	table.insert(storage,watchedObject) -- add to table
end
print("Reference lost here!")

-- Line that actively creates objects and happens to trigger Roblox garbage collector.
game:GetService("RunService"):BindToRenderStep("",0,function() end)

repeat task.wait(.1) until storage[1] == nil
print("Watched object was cleared from memory!")

[SelDraken]

So they are GC as soon as they are returned with no reference, or at termination of function, or at termination of script?

Considering an AnimationTrack has a reference to the Animation Instance that it was loaded from, does that make any difference, could the Track remain in memory until the Animation Instance is destroyed?

[PhoenixRessusection (PhoenixCausesOof)]

@SelDraken

So they are GC as soon as they are returned with no reference, or at termination of function, or at termination of script?

I don’t know this one.

@SelDraken

Considering an AnimationTrack has a reference to the Animation Instance that it was loaded from, does that make any difference, could the Track remain in memory until the Animation Instance is destroyed?

I think it does not remain in memory since the Animation property is simply a pointer to the Instance.