MMDK - Moveset Mod Development Kit

MMDK is a REFramework script and mod development kit for creating and researching Lua moveset mods in Street Fighter 6. It creates a dictionary of all the relevant data needed to mod movesets for each fighter, along with functions and methods to change and add-to various aspects of the moves, and then allows you to edit this dictionary at the start of each match using a Lua file.

It also can produce a "Moveset Research" window where you can set the current move being performed, view its keys live and skip frame-by-frame as they are executed. Combined with the Hitbox Viewer, it can provide a lot of insight into SF6's mechanics.

MMDK allows for full moveset modding including adding entirely new moves with new command inputs while using animations, VFX, keyframe data and damage data from any characters. Mods for MMDK are created as Lua files and multiple of them can run on a character per match.

Installation

1. Download REFramework SF6.zip here (must be newer than Sept 8 2023) and place its dinput8.dll in your game folder
2. Download this repository under Code -> Download as Zip and extract the the contents of each folder inside to your game folder or install as a mod with Fluffy Mod Manager

EMV Engine

Download EMV Engine + Console to see useful control panels for each object (including keys) while developing moveset mods, allowing you to do live testing more easily. EMV is also required to see the imgui menu trees for the fighter in the Moveset Research window.

Usage

1. Open REFramework's main window by pressing Insert (default)
2. Navigate to 'Script Generated UI' and open the MMDK menu
3. Here you can enable and disable the automatic modification of specific characters by the mod's fighter Lua files, control which mods are active for what characters, control individual mod options, and set the visibility of the Moveset Research window

The Street Fighter Battle System

• Street Fighter 6 uses the same battle system as Street Fighter V and IV (and maybe earlier), ported into RE Engine's "Managed Objects"
• The battle system for each fighter is completely independent from their visual appearance (mesh, GameObject); one can exist without the other
• Each fighter has a list of "Actions" (moves), each identified by a number ID
• Each Action has 50+ arrays of keys for different key types (most empty) across its duration
• A Key activates game logic for the character over a specific frame-range of the action

Key Types

• A MotionKey activates an animation (MotionID) from a motlist file (MotionType) at a certain frame
• A AttackCollisionKey activates a hitbox rectangle from the character's rectangle list over a frame range, and applies damage from a linked 'HIT_DT_TBL' when the hit connects
• A DamageCollisionKey activates a hurtbox rectangle over a frame range
• A TriggerKey determines the move's cancel list (what actions the move can transition into)
• A VfxKey plays a visual effect
• A BranchKey connects actions together automatically without player inputs
• A ShotKey spawns a projectile (another action)
• A SEKey plays a sound effect by its unique ID (number)
• A VoiceKey plays a voice line by its unique ID (number)
• A FacialKey plays a facial animation, similar to a MotionKey
• A SteerKey moves the fighter in a X,Y direction
• A PlaceKey also moves a fighter in a X,Y direction during a move, but frame-by-frame
• A LockKey links certain actions together and can apply damage in some cases
• Various other types of keys are also available; test them in the Moveset Research window with EMV Engine

The 'Moveset Research' Window

Under REFramework Script Generated UI, MMDK features a checkbox to enable a Moveset Research window. This window will appear during a match and allow you to trigger moves from the fighter's list, seek across the frames of their move, play in slow motion (or reverse), and seek frame by frame. It can also preview animations and sound effects, among other things.

Functionalities of the Moveset Research window are largely explained through its tooltips; hover your mouse over each element to see what it does.

Scripting Fighter Lua Files

MMDK provides a lua template file for each fighter by name, under reframework/autorun/MMDK. These files each contain a function called apply_moveset_changes, which is automatically run when the character is enabled in the mod and they are detected in a match.

Within this function, you have access to many useful tables and objects from the battle system for the context of modding that character's moveset, all contained in the data parameter. data is a lua class, and it has several attached methods that facilitate adding new objects such as Actions, VFX, and Triggers to the moveset.

• The data parameter contains data.moves_dict, which has a dictionary of actions/moves (as Lua tables). You can assign a move to a local variable such as Juri's:

local MyAction = data.moves_dict.By_Name.SPA_TENSINREN_L

• Each action will have subtables for its active keys, such as MyAction.TriggerKey[1](for the first key in the Lua table of the list), MyAction.AttackCollisionKey.list (for the actual List object), etc.

NOTE: RE Engine objects use 0-based indexing and are actually parts of the game, while Lua uses 1-based indexing and its tables are only part of MDMK. MyAction.TriggerKey is a Lua table while MyAction.TriggerKey.list isn't, so it's important to know the difference

• You can also access the keys through the fab 'FAB_ACTION 'object of the action, which has the 54+ keys lists as an array called MyAction.fab.Keys and also has the master frame count of an action

• The MyAction.dmg table can exist if a move has an AttackCollisionKey that does damage. Here contains a HIT_DT_TBL, which has 20 different param subtables for different scenarios like being in midair or on the ground when an attack connects. A damage table from an AttackCollisionKey that uses AttackDataIndex 15 can be accessed as MyAction.dmg[15]

• The MyAction.box table may also be present, containing hurtbox and hitbox rectangles for the move

• The MyAction.vfx table contains the VFX elements used by a move

• The MyAction.trigger table contains the BCM.TRIGGER elements used by a move, dictated by its TriggerKeys. These decide how a move is inputted by button presses

• The MyAction.tgroups table contains information about TriggerGroups for a move. These are lists of other actions which the move can cancel into

Lua Basics

For a general understanding of Lua, check out the official Programming in Lua textbook and read through Part I.

Then check out the REFramework guide to see which APIs you have available within a REFramework script like this.

Functions.lua

Functions.lua is included with MMDK and is shared among all its scripts by Lua's 'require' function. Its functions can be accessed through the table fn, by default. Check the source code for a description of each function, provided in comments. Some useful functions being:

• edit_obj - takes a RE Managed object and a table of fields/properties vs values in which to change, and changes them. Use the value "nil" (in quotes) to set a field to nil (delete it).
• append_to_list - takes a RE Managed Object 'Generic.Dictionary/List' object and adds a new element to it, then returns the incremented list
• append_key - Takes a RE Engine System.Collections.Generic.List object, a string KeyType, and a table of field names vs values and adds a new instance of that key to the list object while applying the fields table to it as changes
• clone - Takes a RE Managed Object and returns a basic duplicate of it. Fields of the object are cloned as well unless they are System.Arrays or System.Collections objects
• insert_list/array - Inserts elements from list B (or just element B) into list A at the given index

Fighter Lua Examples

Check out 'Ken Donkey Kick.lua' and 'SF6 Balance Tweaks.lua' for some working examples of MDMK scripts. Since these are Lua scripts, you have full access to what REFramework provides inside each mod and can add things like loading options from json files or creating hooks and callbacks to support your changes.

There are also mods to disable parry/perfect parry, Drive Impact and Drive Rush.

Getting a move:

local moves_by_name = data.moves_dict.By_Name
local ATK_5LP = moves_by_name["ATK_5LP"] --Light punch
-- or --
local moves_by_id = data.moves_dict.By_ID
local ATK_5LP = moves_by_id[600] --Light punch

Getting a move from another character

local ryu_data = data:get_simple_fighter_data("Ryu")
local ryu_moves_by_id = ryu_data.moves_dict.By_ID
local ryu_ATK_5HK = ryu_moves_by_id[617]

Editing damage data:

--ATK_5LP

for attack_idx, dmg_tbl in pairs(ATK_5LP.dmg) do
    --Only going through dmg params for standing and crouching:
    for i, param_idx in ipairs(hit_types.s_c_only) do
        --Use 'to_isvec2' to save special isvec2 Vector2 fields like FloorDest
        edit_obj(dmg_tbl.param[param_idx], {DmgType=11, MoveType=15,  JuggleLimit=15, JuggleAdd=1, FloorDest=to_isvec2(50, 80)})
        
        --or you can save fields one at a time:
        dmg_tbl.param[tbl_idx].DmgType = 11
        dmg_tbl.param[tbl_idx].MoveType