State Machine Design

In order to manage the movement and controls of the kinematic character controller, the OpenKCC will use a Finite State Machine (FSM) based design to manage character actions.

The character controller will have high level "states" that can be changed based on external input or internal changes. The character will act differently based on these states.

State Overview

The state machine for the OpenKCC is composed of a few different states.

• Idling - When the player is standing still on the ground
• Walking - When the player is moving around
• Jumping - When the player starts the jumping action
• Falling - When the player is not standing on something
• Sliding - When the player is standing on a steep surface
• Landing - Brief transition period between falling and grounded states

Each of these states will have a different set of capabilities and behaviors and will transition to other states based on external input.

Transition Diagram

stateDiagram
    [*] --> Idling

    Idling --> Walking : MoveInput
    Idling --> Falling : LeaveGround
    Idling --> Sliding : SteepSlope
    Idling --> Jumping : JumpEvent

    Jumping --> Falling : Animation Completed
    Jumping --> Landing : Grounded
    Jumping --> Sliding : SteepSlope

    Landing --> Idling : Animation Completed
    Landing --> Walking : MoveInput
    Landing --> Falling : LeaveGround
    Landing --> Sliding : SteepSlope

    Walking --> Idling : StopMove
    Walking --> Falling : LeaveGround
    Walking --> Sliding : SteepSlope

    Sliding --> Falling : LeaveGround
    Sliding --> Landing : Grounded
    Sliding --> Jumping : JumpEvent

    Falling --> Landing : Grounded
    Falling --> Sliding : SteepSlope
    Falling --> LongFalling : Wait 4 Seconds

    LongFalling --> Landing : Grounded
    LongFalling --> Sliding : SteepSlope