How to implement monster spawning with delay?

Questions
#1

Hello, as a result of writing the game I ran into a misunderstanding of spawning mobs with a certain cooldown. When using the code inside the function, its execution is instantaneous, at the same time I tried to use timer.delay, but nothing worked + when using it, monsters spawned and immediately disappeared.


function mobSpawn(self, wavePoint)
	while(wavePoint > 0) 
	do
		if wavePoint >= 5 then 
			local numMonster = math.random(1, 5)
			wavePoint = wavePoint - numMonster
			monster_name = monster_list[numMonster]
			factory.create(monster[monster_name].factory_url, position, nil, {damage = monster[monster_name].damage, speed = monster[monster_name].speed, hp = monster[monster_name].hp, height = monster[monster_name].height, experience = monster[monster_name].experience})
		else
			local numMonster = math.random(1, wavePoint)
			wavePoint = wavePoint - numMonster
			factory.create(monster[monster_name].factory_url, position, nil, {damage = monster[monster_name].damage, speed = monster[monster_name].speed, hp = monster[monster_name].hp, height = monster[monster_name].height, experience = monster[monster_name].experience})
		end
	end
end

Here’s how I tried to implement .delay

{...}
		if wavePoint >= 5 then 
			local numMonster = math.random(1, 5)
			wavePoint = wavePoint - numMonster
			monster_name = monster_list[numMonster]
			timer.delay(1, false, function()
				factory.create(monster[monster_name].factory_url, position, nil, {damage = monster[monster_name].damage, speed = monster[monster_name].speed, hp = monster[monster_name].hp, height = monster[monster_name].height, experience = monster[monster_name].experience})
			end)
{...}
1 Like
#2

Is your ‘position’ variable defined somewhere? Looks like it’s passed to factory.create but not defined beforehand. That might be why your monsters disappear.

#3

No, unfortunately, factory.create() itself works completely correctly + immediately after monsters appear final() is triggered (as part of the test after removing mobs in the console writes how much experience they brought).

#4

Weird, turns out some monster disappears after appearing, I’ll go double-check the script of the monsters themselves.

#5

As it turns out I forgot to prescribe collision groups to all monsters except ogres. As a result, when spawning they hit each other and instantly disappeared, this problem has been solved.

But there’s still a problem with their appearance, because timer.delay() will still spawn them all together, except that it won’t be instantaneous, but after 5 seconds. (I need them to spawn one by one with a delay).

image

Actual script:

function mobSpawn(self, wavePoint)
	while(wavePoint > 0) 
	do
		if wavePoint >= 5 then 
			local numMonster = math.random(1, 5)
			wavePoint = wavePoint - numMonster
			local monster_name = monster_list[numMonster]
			timer.delay(5, false, function()
				factory.create(monster[monster_name].factory_url, position, nil, {damage = monster[monster_name].damage, speed = monster[monster_name].speed, hp = monster[monster_name].hp, height = monster[monster_name].height, experience = monster[monster_name].experience})
			end)
				else
			local numMonster = math.random(1, wavePoint)
			wavePoint = wavePoint - numMonster
			local monster_name = monster_list[numMonster]
			timer.delay(5, false, function()
			factory.create(monster[monster_name].factory_url, position, nil, {damage = monster[monster_name].damage, speed = monster[monster_name].speed, hp = monster[monster_name].hp, height = monster[monster_name].height, experience = monster[monster_name].experience})
			end)
		end
	end
end
#6

Instead of using a while loop, which will run infinitely on the first frame until everything is spawned, you should delay the mobSpawn function itself to make them appear one by one. For example:

function mobSpawn(self, wavePoint)
	if wavePoint > 0 then
		if wavePoint >= 5 then 
			local numMonster = math.random(1, 5)
			wavePoint = wavePoint - numMonster
			local monster_name = monster_list[numMonster]
			factory.create(monster[monster_name].factory_url, position, nil, {damage = monster[monster_name].damage, speed = monster[monster_name].speed, hp = monster[monster_name].hp, height = monster[monster_name].height, experience = monster[monster_name].experience})
		else
			local numMonster = math.random(1, wavePoint)
			wavePoint = wavePoint - numMonster
			local monster_name = monster_list[numMonster]
			factory.create(monster[monster_name].factory_url, position, nil, {damage = monster[monster_name].damage, speed = monster[monster_name].speed, hp = monster[monster_name].hp, height = monster[monster_name].height, experience = monster[monster_name].experience})
		end
		timer.delay(5, false, function ()
			mobSpawn(self, wavePoint)
		end)
	end
end
4 Likes
#7

Is it a recursive function ? This is the first time I see its use in practice, thank you very much !

Can I explain its work in a separate post ? I’ll mention you, of course.

#8

Sure, if the code works for you, feel free to share the approach.