Beat Saber Map Generator

There are things computers can't do very well. Understand pacing and emphasis for example. This approach is to translate keyboard input into notes. To leave some control to the user so the right notes get emphasis, and have breaks are where you want them to be.

Beat Saber Map Generator is a deterministic map generator. It has factories which produces notes, and validators that ensure the map's quality. The most important validator, the MatrixValidator uses an 8 dimentional transition matrix describing every possible transition from one note to the next. The matrix is parsed from existing maps. This way, the user can give a their map the same "feeling" (to some degree) by giving it specific maps to build its matrix from.
The matrix can be of type bool to describe whether a transition is legal. Or float describing the probability of one note transitioning the a spesific state. For a note in the matrix, the sum of the probabilities of all notes it can transition to is 1, making the TransitionMatrix<float> a markov chain.

The plan is to have many kinds of factories to bring variety, along with many knobs and dials to change the outcome though config files. And many validators to cover the mapping errors that aren't picked up by implicitly the transition matrix validator among with edge cases (the maps used yo build the matrix may contain errors).

(Generated map with MatrixValidator and DoubleDownValidator)

Factories

• Weighted Transition matrix. Build a markov chain with note transition pick random based on the weights going out of that node.
• Template. Has a collection of predefined patterns and puts them where they match the best.
• Random. Pick the next note random based on some simple weights. More at the bottom, colors on theirs side mostly.
• Symmetrical random. Generate two notes at same timestamp the are symmetrical to a center plane or a center point.

Validators

• Transition Matrix
• Double down
• Vision block
• Tangled arms
• Inverted colors. If inverted for too long
• Distance. If the distance to travel is inhuman.
• Single frame same direction. When several notes on same timestamp, they must be in a line.
• Bomb after note. If a bomb is in swing path after a note

Installation

1. sudo apt-get install libsfml-dev
2. git clone [email protected]:JonShard/BeatSaberMapGenerator.git
3. cd BeatSaberMapGenerator
4. make
5. ./generator.out song.ogg

Usage

Note that right now the generator requires a BPM of 120 in the info file as the program has no way to get this right now.
generator.out [AUDIO FILE] [JSON NOTATIONS]

Parameters

• -a [MAP FILE...] [OPTIONAL --clean] Analyse a map and build transition matrix. Stored in binaryTransitionMatrix.data. Optional falg --clean to discard existing matrix.
• -g [JSON NOTATIONS] Generate map from existing keyframes file. Optional parameter --seed 42.

Examples

./generator.out songs/createOW/create.ogg /songs/createOW/keyframes.json
./generator.out -a songs/createOW/ExpertPlusStandard.dat --clean
./generator.out -g keyframes.json

Config File

Config file config.json is loaded from the same location as the program.
Format:

{
    "generator": {
        "noteClusterTime": float - Time that defines how close notes have to be to be considered in the same cluser or "frame" (seconds).
        "factories": {
            "maxAttempts": int - The maximum amount of attempts to generate from note A, a valid note B before backtracking by removing note A.
            "randomFactory": {
                "enabled": bool - Is the random factory enabled.
            }
            "symmetricalFactory": {
                "enabled": bool - Is the symmetrical factory enabled.
                "centerPointMode": bool - Note: One of the three symmetry modes must be enabled. Allow outcomes where the pair of notes are complete opposites, mirrored accross a center point. If one note is top left with direction up, the other will be bottom right with direction down.
                "horizontalMode": bool - Note: One of the three symmetry modes must be enabled. Allow outcomes where the generated notes are symmertrical along a vertical plane. Two notes on same layer with same direction, but different lanes.
                "verticalMode": bool - Note: One of the three symmetry modes must be enabled. Allow outcomes where the generated notes are symmetrical along a horizontal plane. Two notes on same lane, top and bottom. 
                "allowOffsetPlane": bool - Allow the symmmetry plane be offset one note left or right (only applicable to vertical mode).
                "allowNotesInCenter": bool - Allow notes to be generatred in the two ceneter positions.  
            }
        },
        "validators": {
            "validateTimeAfterNote": float - Time after a note in which the validator will care if an illegal note is placed (seconds).
            "matrixValidator": {
                "enabled": bool - Is the matrix validator enabled.
                "binaryMatrixFilePath": string - Path to ascii file containing binary transition matrix containing only 1, 0 and whitespace.  
            },
            "doubleDownValidator": {
                "enabled": bool - Is the double down validator enabled.
                "angleToBeDoubleDown": The difference in angles two notes have to be for theirs transition to qualify as a double down. Possible values: 0, 45, 90, 135. 180 would deny all notes always.
            }
            "adjacentValidator": {
                "enabled": bool - Is the adjacent validator enabled.
                "timeToBeAdjacent": float - The maximum a time difference between two notes in order for them to be considered adjacent.
            }
        }
    },
    "editor": {
        "autosaveEnabled": bool
        "windowWidth": int - Amount of pixles of the editor window in X direction.
        "windowHeight": int - Amount of pixles of the editor window in Y direction.
    }
}

Example:

{
    "generator": {
        "noteClusterTime": 0.01,
        "factories": {
            "maxAttempts": 1000,
            "randomFactory": {
                "enabled": true
            },
            "symmetricalFactory": {
                "enabled": true,
                "centerPointMode": true,
                "horizontalMode": true,
                "verticalMode": true,
                "allowOffsetPlane": true,
                "allowNotesInCenter": false
            }
        },
        "validators": {
            "validateTimeAfterNote": 2,
            "matrixValidator": {
                "enabled": true,
                "binaryMatrixFilePath": "binaryTransitionMatrix.data"
            },
            "doubleDownValidator": {
                "enabled": true,
                "angleToBeDoubleDown": 90
            },
            "adjacentValidator": {
                "enabled": true,
                "timeToBeAdjacent": 2
            }
        }
    },
    "editor": {
        "autosaveEnabled": false,
        "windowWidth": 1600,
        "windowHeight": 900
    }
}

Editor Keybindings

Create a keyframe by pressing one or several keys in the range A-Z + 0-9. Pressing several at a time will register the keyframe with several concurrent presses with a max of 4, indicating the intensity of that keyframe.

Key	Action
Space	Play / pause
F5	Save notation
F10	Generate map
Scroll	Generate map
Backspace	Go to start
Numpad+	Zoom in
Numpad-	Zoom out
Page up	Speed up
Page down	Speed down
End	Reset speed