Base 'Parameter Curve' Generation 'Growth' Formulas?

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Started by Roguedeus 12 posts View original ↗
  1. Roguedeus
    #1 Source
    I'm terrible at advanced Math, and for the life of me can't seem to figure out how to re-create the curve growth biases (Fast > Normal > Slow) in the toolset.

    I have searched the internet, but without knowing what I'm looking for, all I seem to find are normal distribution formulas and instructions on how to generate line graphs with existing data... but not generating new data based on Min/Max values.

    I'd appreciate any advice. Or just an example formula that I can pick apart.

    Thanks!
  2. TheoAllen
    #2 Source
    The normal formula should be y = m + x*n (linear) where 'm' is the starting stat, 'x' is the level, and 'n' is the growth multiplier.
    A fast or slow formula I believe it's by adding trigonometric function to the linear line formula so it works like a curve.
    I haven't really tried to replicate the formula, but at least I kinda know where to start.
  3. kartacha
    #3 Source
    Do you speak about the particular formula for EXP in MV? If that is so I obvserved that it is equal to:

    <Something>*Base+(Extra*(LV-1))

    This something is somehow related to Acc A and B. I observed that when Acc A is 10 and when Acc A is 50 the <something> is as follows:

    upload_2018-7-26_3-7-47.png

    A good guess may be that the <something> contains multiplication by (LV-1) since it is with 0 for LV 1 and is 1 at LV2. Later it explodes and I cannot really make up what happens.
  4. TheoAllen
    #4 Source
    I believe it's not about EXP, but stat growth (ATK/DEF/MAT/MDF), but that EXP formula is also interesting.
  5. Roguedeus
    #5 Source
    TheoAllen said:
    I believe it's not about EXP, but stat growth (ATK/DEF/MAT/MDF), but that EXP formula is also interesting.

    Correct. The formula for EXP is in the rpg_object.js script.
    However, the Base Param formula appears to be internal to the toolset, and generates data in the Classes.json file.
    No formula to find.
  6. Another Fen
    #6 Source
    Can't say if it is true for MV so you may have to test it, but at least XP and VXAce seemed to use this formula:

    min + floor((1 - rate) * ceil((max-min) * (level-1)/98.0) + rate * ceil((max-min) * ((level-1)/98.0)^2))

    min -> Level 1 value
    max -> Level 99 value
    rate -> Growth rate: (Fast: -1, Average: 0, Slow: +1)

    Since MV uses Javascript which does all calculations with decimals by default, I'd not be surprised if at least the roundings were a bit different in MV though.
  7. Roguedeus
    #7 Source
    I've gona ahead and attempted to gleen what I can from the EXP formula... And I've run into something odd.

    This code:

    Code:
    Game_Actor.prototype.expForLevel = function(level) {
    var c = this.currentClass();
    var basis = c.expParams[0];
    var extra = c.expParams[1];
    var acc_a = c.expParams[2];
    var acc_b = c.expParams[3];
    return Math.round(basis*(Math.pow(level-1, 0.9+acc_a/250))*level*
            (level+1)/(6+Math.pow(level,2)/50/acc_b)+(level-1)*extra);
};

    Is supposed to be generating this curve:



    But when I recreate the formula in excel, I get this output: (Column C)
    (I've checked every single cell and the formula is accurate for all 15)



    It' may not have any significance on my actual question, but it has me wondering.

    I have also looked into obvious ways of applying a Trigonometric Function to a line generation formula and, so far nothing helpful.


    Edit:
    I think I've managed to figure out that whatever is going on, is merely finding the correct logarithmic formula to multiply the line values by, in a way to maintain the initial and end values.
  8. kartacha
    #8 Source
    Could someone please write one of these as a mathematical equation? I am really unable to read it like JS, Ruby or like an Excel formula and I am genuinely interested in that.
  9. TheoAllen
    #9 Source
    kartacha said:
    Could someone please write one of these as a mathematical equation? I am really unable to read it like JS, Ruby or like an Excel formula and I am genuinely interested in that.
    If you mean, Another Fen's formula, I'm not sure how the equation in math equation.
    But, in their formula, floor(...) means when a number is decimal, it rounded down. For example, floor(1.7) is equal as 1
    In other hand, ceil(...) means when a number is decimal, it rounded up. For example ceil(1.2) is equal as 2
    How would you translate it in math equation?
  10. Roguedeus
    #10 Source
    I've figured out how to effectively add a log function to linear generation.

    18_0725_expGen_3.JPG

    But now I just need to wrap my head around how to 'simply' flip the curve...
  11. TheoAllen
    #11 Source
    lol I kinda hate working with log. Tell me when you figure out the formula.
  12. Zarsla
    #12 Source
    @kartacha


    [basis * [(level -1) ^(0.9 + (acc_a /250))] * level * (level + 1)]/[6 + [([level ^ 2]/50)/acc_b] + [(level -1) *extra]

    And then round the answer.