How to create respawning resource nodes using a single variable and a common event.

Trihan · 2022-01-22T12:37:39+0900

Tutorial Title: How to create respawning resource nodes Brief Description: This tutorial will teach you how to implement a system of harvestable resource nodes which replenish themselves on a timer without the need for many game variables or huge nests of conditional branches. Requirements: None, though a basic familiarity with Javascript would be a bonus for understanding the script we'll be writing. Tutorial Body: We're going to look at how to create mining nodes for stone, but these concepts can be modified to apply to basically anything harvestable; plants, ore, fish, you name it. Due to how the data will be stored, it may not be entirely suitable for a full-on farming system where you'll have a lot of crops growing at once, but for all I know it'll work for that too. Feel free to experiment. IMPORTANT: Any time I refer to "variable" in the tutorial, if it's prefaced with "[JS]" I mean a JavaScript variable (the kind you create in a script command) and it it's prefaced with "[RM]" I mean the built-in RPG Maker game variables (the ones you manipulate with the Control Variables command, which can also be manipulated in code using $gameVariables.value(x) to get a variable's value, and $gameVariables.setValue(x, value) to set it) So first things first, let's create a rock event. The main contents of the event, such as animations, text, item gain etc. can be anything you want; the only important part is the script at the end, and turning on self switch A to activate page 2, which has the graphic of the empty node. My event looks like this: Let's break down that script and look at what it's doing: JavaScript: if ($gameVariables.value(1) === 0) $gameVariables.setValue(1, []); $gameVariables.value(1).push([this._mapId, this._eventId, 500]); If [RM]variable 1 is equal to 0, set it to an empty array. Then push to that array another array consisting of the current map ID, the current event ID, and the value 500. The first line is to ensure that the [RM]variable we're using becomes an array before we try to store multiple values in it, otherwise we'll get an error. The second line is storing an array of data identifying this particular node event and the number of frames it'll take to respawn. So in this case, 500 frames, or just over 8 seconds. this._mapId and this._eventId will already return whatever the current map is, and the ID of the event the code is running inside, so you don't need to change this, it'll work as-is with any event you paste it into. It should hopefully go without saying, but the [RM]variable ID used must be one you're not using elsewhere in the game. And now, let's look at our common event (these are created in the "Common Events" tab of the database): This will be a parallel process event. Parallel process events never just run by themselves with no input; they always require a specified switch to be turned on before they'll start, so you'll need to make sure its activation switch is turned on at some point. Usually for things like this I have an autorun event at the start of the game which does setup like this and then either erases itself or turns on a self switch to move to a non-autorun page, but the exact method of turning on the switch is up to you. Note from this point that any time I refer to the "1" in $gameVariables.value or $gameVariables.setValue, you must ensure that you use the same [RM]variable ID as you used for the event step above. Everything else can be copied as-is. The conditional branch script condition, $gameVariables.value(1) !== 0, is just making sure the [RM]variable's value is not 0. This is to ensure that we don't waste time running the inner code if the player has never interacted with a node. As soon as they do, the line from the event which turns the [RM]variable into an array and then pushes an array into it will cause this condition to be true, and start running the rest of the code: JavaScript: for (const oreData of $gameVariables.value(1)) { oreData[2]--; if (oreData[2] === 0) { $gameSelfSwitches.setValue([oreData[0], oreData[1], 'A'], false); $gameVariables.value(1).remove(oreData); } } So what's happening here is that we're running a loop that goes through each element of [RM]variable 1's value, which as mentioned before is an array of arrays (an array just being a [JS]variable that can hold more than one value inside it). Each time we loop, we'll store the current element in a [JS]variable called oreData. It doesn't have to be oreData, you can call it anything you like as long as it starts with a letter, underscore or dollar sign. The important thing is that every occurrence here of "oreData" must be exactly the same name or the script won't work. First, we reduce the value of oreData's third element (index 2) by 1. Then, if that value is equal to 0, we turn off a self switch, using oreData's first element as the map ID, its second element as the event ID, and 'A' as the self switch letter. Finally, we remove the oreData element from the [RM]variable.…

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Started by Trihan Jan 22, 2022, 03:37 AM 48 posts Page 3 of 3 View original ↗

Trihan

#41 Dec 17, 2023, 12:05 AM Source

Candacis said:
Thanks for this tutorial, it really helped me out creating a small gathering system.
I set the timer to 86.400, so it takes 24min to respawn.

I'm wondering if I could do a second variable for a longer respawn time and would this need a second common event, too or could I put it in the same common event?

Also, what would happen, if the player doesn't wait it out, but goes to bed at night?
Is it possible that an innkeeper event could add specific time/frames to the timer?
Let's say a 24 hour day takes 86.400 frames, but one day the player doesn't run around at night, but goes to sleep for 8 hours. Could I somehow add 28.800 frames to the timer?
If you have nodes that take longer to respawn, just put a different number in when you push that node to the array. It doesn't have to be the same for every one.

Likewise, if you want to have 8 hours pass, do the thing in the common event but subtract the number of frames you want instead of 1, and check for <= 0 instead of === 0. Everything else should function the same.
Candacis

#42 Dec 17, 2023, 09:23 AM Source

Thank you both for your fast replies!
I woke up 8 hours later feeling rested and reading your answers :D

Now, I'm thinking, if I have an Innkeeper event, but instead of fix 8 hours sleep, I want players always to wake up at 7 in the morning (I have a time system common event that counts the hours/time).
But what happens, if the players goes to sleep at midnight? Or at 9 in the evening? Then maybe they sleep more or less than 8 hours.

What complicated math shenanigans can I do to count that?
Saradas

#43 Mar 11, 2024, 10:36 AM Source
Trihan said:
Oh, beans, how did I miss this when you posted it?

The reason is that .remove is an MZ-specific array function. Its implementation can be recreated in MV though, all it does is this:

JavaScript:
Array.prototype.remove = function(element) { for (;;) { const index = this.indexOf(element); if (index >= 0) { this.splice(index, 1); } else { return this; } } };
@Trihan
Sorry for asking this but, does this block of code need to be inserted inside rpg-core.js?
If so, does it need to be in a specific position inside the file?
Thank you
Trihan

#44 Mar 11, 2024, 11:24 AM Source

Saradas said:
@Trihan
Sorry for asking this but, does this block of code need to be inserted inside rpg-core.js?
If so, does it need to be in a specific position inside the file?
Thank you
I would add it as its own plugin rather than putting it in a core file.
Siffers

#45 Jul 29, 2024, 07:12 AM Source

How would I go about removing the timer aspect from this and simply reset the nodes by manually calling the common event? I'm using a day/night system and would simply like all nodes to respawn at the start of each day.
ATT_Turan

#46 Jul 29, 2024, 01:24 PM Source
Siffers said:
How would I go about removing the timer aspect from this
From the instructions on the first page:

Trihan said:
The second line is storing an array of data identifying this particular node event and the number of frames it'll take to respawn. So in this case, 500 frames, or just over 8 seconds.
Thus, you'd simply omit the number of frames.
Code:
if ($gameVariables.value(1) === 0) $gameVariables.setValue(1, []); $gameVariables.value(1).push([this._mapId, this._eventId]);
Then you wouldn't have Trihan's parallel event at all; in your day/night common event, when it becomes day, you'd paste his code without any reference to the frames and checking for it to be zero.
Code:
for (const oreData of $gameVariables.value(1)) { $gameSelfSwitches.setValue([oreData[0], oreData[1], 'A'], false); $gameVariables.value(1).remove(oreData); }
Siffers

#47 Jul 29, 2024, 04:54 PM Source

That's what I was thinking, but JS still intimidates me pretty hard at this point.
Thank you for the help ♥

Edit:
Alright, no idea what I did wrong, but it seems to only be resetting half of the nodes at a time.

Edit 2:
Okay, so I just removed the "remove()" part of the code and that seemed to get them all to reset instead of half. I figure that's there to stop the array from being flooded by duplicate entries though, so I manually reset my variable back to it's initial array state.
ian_8819

#48 Nov 13, 2025, 02:16 AM Source

Hello, good day.It was very helpful and works very well. I'm a beginner and I'm learning to make simple plugins (MZ), I'll try to turn it into a plugin.