CustomLua and Variable Calculation

[ds2497]

Hi, I wrote a CustomLua script that generates a random double. Now, I'm trying to mix this value with Variable in a calculation, but when I check the value of Variable, I always get 0. My code is as follows:

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Variable["T001"] = Variable["T001"] + RandNumber(20);

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    public static double RandNumber(double max)
    {
        double randomValue = UnityEngine.Random.Range(0f, (float)max);
        ConsoleProDebug.LogToFilter($"Generated random number: {randomValue}, within range 0 to {max}.", "System");
        return randomValue;
    }

I looked at some other posts, and it seems the correct way is to use math.random(min, max). Although I tested it and found it works, I’d like to know if I misunderstood something, causing my custom lua method not to work correctly.

Lastly, just to add, there's an extra parenthesis at the end of this line in the documentation. I happened to notice it, so I’m mentioning it here: https://www.pixelcrushers.com/dialogue_ ... d_lua.html

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int myCoins = Lua.Run("return Variable['numberOfCoins']").AsInt);

[Tony Li]

Hi,

Your Lua code looks correct. Did any errors or warnings appear in the Console when you ran it?

In any case, I do recommend switching to the built-in math.random() function. This way you don't have to worry about maintaining and debugging a custom RandNumber() function.

[ds2497]

I’ve found the issue and wanted to share it here! My Lua code looks like this:

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Variable["T001"] = Variable["T001"] + RandNumber(20);

In this case, this operation is an increment operation, where the variable is incremented by an additional value. T001 didn’t have a chance to initialize, so the system doesn’t know what value it holds. That’s why it displays 0 and ignores the operation. If the variable T001 needs to perform incremental operations the first time it appears in the game, the correct solution is to set T001 in the editor beforehand.

Oh the other hand, it’s common not to want to manually add such variables. If T001 isn’t added in the editor, it must be initialized in code, as shown below:

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Variable["T001"] = 0;
Variable["T001"] = Variable["T001"] + RandNumber(20);

In my case, this approach doesn’t work because it forces the value to reset to zero, whereas I want the value to increment based on random numbers, including the first time the variable appears. As a result, I opted to add the variable to the editor instead.

Thanks for the help!

[Tony Li]

Hi,

Thanks for your detailed explanation.

BTW, if you ever do want to assign a random number in Lua code, use can use math.random() such as the code below to assign a random number in the range [1,10]:

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Variable["T001"] = math.random(10);
Variable["T001"] = Variable["T001"] + RandNumber(20);

[ds2497]

I have one more question regarding Variables. Is it possible for this value to be saved? Currently, my save code is as follows:

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private static void SaveExternalData(int slotIdx)
{
	PixelCrushers.SaveSystem.SaveToSlot(slotIdx);
}

private static void LoadExternalData(int slotIdx)
{
	PersistentDataManager.LevelWillBeUnloaded();
	PixelCrushers.SaveSystem.LoadFromSlot(slotIdx);
}

For some reason, the Variable is not being saved when I save the game. I'm not sure if there's an issue with my code or if Variables simply can't be saved. My understanding is that when using the SaveSystem, there’s no need to manually call ApplySaveData or PersistentDataManager. Is my approach correct?

[Tony Li]

Hi,

Make sure your Dialogue Manager GameObject has a Dialogue System Saver component, and that you've assigned a unique key. I usually use "ds" for the Key.

[ds2497]

Thank you so much! It works!

[ds2497]

I have one more question about Dialogue System Saver: If I set the Persistent Data Setting under Dialogue Manager to All Game Objects, would enabling Save Across Scene Changes in the Saver be redundant? Could you briefly explain the interaction between the following?

1. Persistent Data Setting in the Dialogue System
2. Save Across Scene Changes in the Saver
3. Save Current Scene in the Save System

I conducted various tests, and my current understanding is that if Persistent Data Setting is set to All Game Objects, then the Saver does not need to have Save Across Scene Changes enabled.

Would the save system function correctly as long as at least one of these three options is enabled? Additionally, I'm also curious about how QuestJournal handles saving. It doesn’t seem to have any Saver component attached…

[Tony Li]

Hi,

Leave Persistent Data Settings set to Only Registered GameObjects. This setting only affects "Persistent Data" components, which have been superceded by the save system and "Saver" component.

In a Saver, Save Across Scene Changes retains the saver's save data when changing scenes. So when you return to the scene with the saver, it will have save data to restore. Most of the time you want this ticked, but for less important GameObjects such as the position of a bird flying randomly in the scene you can untick it to dump the data when the player leaves the scene.

Save Current Scene saves the name of the current scene. When you load a saved game, it first loads this scene.

[ds2497]

Thanks for the answer! I still need to take my time figuring out some details, but you’ve given me a good basic understanding.