unity 2d キャラクター 素材 — 2D Character Feel Kit (C# only, no sprite art): coyote time, jump buffer, i-frames, hit flash, health bar. 26 Inspector fields, 6 presets, Unity 2021.3+

Global Game Jam runs 48 hours. Coyote time, jump buffering, variable jump height, an invincibility window and a hit flash are already written and already commented here — 26 values in the Inspector and 6 character presets, so those hours go into the level instead of into re-deriving a jump arc.

Import

1. Unity 2021.3+ : Assets > Import Package > Custom Package
2. Assets/Character2DFeelKit

What is inside (7)

What you change in the Inspector

Free script — Runtime/Character2DMotor.cs

Copy this file into your project as-is. It is one of the scripts in the pack.

using UnityEngine;

/// <summary>
/// 2D platformer movement with the feel details tutorials leave out:
/// coyote time, jump buffering, variable jump height, air jumps and a
/// separate fall gravity.
///
/// Drive it with the legacy Input Manager (Read Legacy Input, on by default)
/// or turn that off and call SetMoveInput, RequestJump and ReleaseJump from
/// your own input code. Both input systems are supported that way.
/// </summary>
[RequireComponent(typeof(Rigidbody2D))]
[DisallowMultipleComponent]
[AddComponentMenu("2D Character Feel Kit/Character 2D Motor")]
public class Character2DMotor : MonoBehaviour
{
    [Header("Run")]
    [Tooltip("Top horizontal speed, in world units per second.")]
    [Min(0f)] public float moveSpeed = 8f;

    [Tooltip("How hard the character is pushed towards top speed on the ground, in units per second squared. Higher feels snappier.")]
    [Min(0f)] public float groundAcceleration = 70f;

    [Tooltip("How hard the character is slowed on the ground when you let go. Set it below groundAcceleration for a slide.")]
    [Min(0f)] public float groundDeceleration = 90f;

    [Tooltip("Air control. Below groundAcceleration makes a jump feel committed instead of steerable.")]
    [Min(0f)] public float airAcceleration = 35f;

    [Header("Jump")]
    [Tooltip("Peak jump height in world units, measured from take-off. The take-off velocity is solved from this and the current gravity, so changing gravity does not change your jump height.")]
    [Min(0f)] public float jumpHeight = 3.2f;

    [Tooltip("Jumps allowed after leaving the ground. 0 is a single jump, 1 is a double jump.")]
    [Min(0)] public int extraAirJumps = 1;

    [Tooltip("Seconds after walking off a ledge during which a jump press still works. 0.08 to 0.15 feels generous without feeling loose.")]
    [Min(0f)] public float coyoteTime = 0.12f;

    [Tooltip("Seconds before landing during which a jump press is remembered and fired the moment the feet touch down.")]
    [Min(0f)] public float jumpBufferTime = 0.12f;

    [Tooltip("Gravity multiplier while falling. Above 1 makes the character drop faster than it rose, which is what most good platformers do.")]
    [Min(0f)] public float fallGravityMultiplier = 2.2f;

    [Tooltip("Gravity multiplier while still rising after the jump button was released. This is what turns a short tap into a short hop.")]
    [Min(0f)] public float lowJumpGravityMultiplier = 2.8f;

    [Tooltip("Fastest the character may fall, in units per second. Also stops fast falls tunnelling through thin colliders.")]
    [Min(0f)] public float maxFallSpeed = 22f;

    [Header("Ground check")]
    [Tooltip("Layers that count as ground. Do not include the layer this character is on.")]
    public LayerMask groundLayers = 1;

    [Tooltip("Thickness of the box used to look for ground under the feet, in world units.")]
    [Min(0f)] public float groundProbeThickness = 0.08f;

    [Header("Input")]
    [Tooltip("Read the legacy Input Manager axes Horizontal and Jump. Turn this off and call SetMoveInput, RequestJump and ReleaseJump from your own input code.")]
    public bool readLegacyInput = true;

    public event System.Action Jumped;
    public event System.Action Landed;

    public bool IsGrounded { get { return _grounded; } }
    public float MoveInput { get { return _moveInput; } }
    public float HorizontalSpeed { get { return _body != null ? _body.velocity.x : 0f; } }
    public float VerticalSpeed { get { return _body != null ? _body.velocity.y : 0f; } }

    Rigidbody2D _body;
    Collider2D _collider;
    float _moveInput;
    float _coyoteTimer;
    float _bufferTimer;
    int _airJumpsUsed;
    bool _grounded;
    bool _wasGrounded;
    bool _jumpHeld;
    bool _jumpFiredThisStep;

    void Awake()
    {
        _body = GetComponent<Rigidbody2D>();
        _collider = GetComponent<Collider2D>();
        _body.freezeRotation = true;

        if (_collider == null)
        {
            Debug.LogWarning("Character2DMotor: there is no Collider2D on this object, so the ground check has nothing to measure from. Add a CapsuleCollider2D or a BoxCollider2D.", this);
        }

        // The mistake that costs an hour: the character is on a layer that is
        // also listed as ground, so the probe finds the character itself and
        // it never falls. Say so out loud instead of letting them guess.
        if (((1 << gameObject.layer) & groundLayers.value) != 0)
        {
            Debug.LogWarning("Character2DMotor: Ground Layers includes this object's own layer, so the ground check will keep finding the character itself and it will never fall. Put the character on its own layer, or clear that layer from Ground Layers.", this);
        }

        if (_body.gravityScale <= 0f)
        {
            Debug.LogWarning("Character2DMotor: Rigidbody2D Gravity Scale is 0, so there is no arc to solve and the character will not come back down. Set it to 1.", this);
        }
    }

    void Update()
    {
        if (readLegacyInput) ReadLegacyInput();

        if (_grounded) _coyoteTimer = coyoteTime;
        else if (_coyoteTimer > 0f) _coyoteTimer -= Time.deltaTime;

        if (_bufferTimer > 0f) _bufferTimer -= Time.deltaTime;
    }

    void ReadLegacyInput()
    {
        // If the project is set to Input System Package only, the legacy calls
        // throw. Switch ourselves off once, say what to call instead, and never
        // throw again.
        try
        {
            _moveInput = Input.GetAxisRaw("Horizontal");
            if (Input.GetButtonDown("Jump")) RequestJump();
            if (Input.GetButtonUp("Jump")) ReleaseJump();
            _jumpHeld = Input.GetButton("Jump");
        }
        catch (System.Exception error)
        {
            readLegacyInput = false;
            Debug.LogWarning("Character2DMotor: the legacy Input Manager is not active in this project, so Read Legacy Input has been switched off. Call SetMoveInput, RequestJump and ReleaseJump from your own input code instead. Details: " + error.Message, this);
        }
    }

    /// <summary>Horizontal input from -1 to 1. Call this from your own input code.</summary>
    public void SetMoveInput(float horizontal)
    {
        _moveInput = Mathf.Clamp(horizontal, -1f, 1f);
    }

    /// <summary>Jump pressed. Buffered, so it still fires if you were slightly early.</summary>
    public void RequestJump()
    {
        _bufferTimer = jumpBufferTime;
        _jumpHeld = true;
    }

    /// <summary>Jump released. Cuts the rise short for a lower hop.</summary>
    public void ReleaseJump()
    {
        _jumpHeld = false;
    }

    void FixedUpdate()
    {
        _jumpFiredThisStep = false;
        UpdateGrounded();
        ApplyHorizontal();
        TryJump();
        ApplyGravity();
    }

    void UpdateGrounded()
    {
        _wasGrounded = _grounded;

        if (_collider == null) { _grounded = false; return; }

        Bounds bounds = _collider.bounds;
        Vector2 centre = new Vector2(bounds.center.x, bounds.min.y - groundProbeThickness * 0.5f);
        Vector2 size = new Vector2(Mathf.Max(0.01f, bounds.size.x * 0.9f), Mathf.Max(0.01f, groundProbeThickness));
        _grounded = Physics2D.OverlapBox(centre, size, 0f, groundLayers) != null;

        // Only give the air jumps back once we are resting or falling, so the
        // frame we leave the ground does not silently refund one.
        if (_grounded && _body.velocity.y <= 0.01f) _airJumpsUsed = 0;

        if (_grounded && !_wasGrounded && Landed != null) Landed();
    }

    void ApplyHorizontal()
    {
        float target = _moveInput * moveSpeed;

        float rate;
        if (!_grounded) rate = airAcceleration;
        else if (Mathf.Abs(target) > 0.01f) rate = groundAcceleration;
        else rate = groundDeceleration;

        float x = Mathf.MoveTowards(_body.velocity.x, target, rate * Time.fixedDeltaTime);
        _body.velocity = new Vector2(x, _body.velocity.y);
    }

    void TryJump()
    {
        if (_jumpFiredThisStep) return;   // one jump per physics step, never two
        if (_bufferTimer <= 0f) return;

        bool groundJump = _grounded || _coyoteTimer > 0f;
        bool airJump = !groundJump && _airJumpsUsed < extraAirJumps;
        if (!groundJump && !airJump) return;

        float gravity = Mathf.Abs(Physics2D.gravity.y) * _body.gravityScale;
        if (gravity <= 0f) return;        // no gravity, no arc to solve

        if (airJump) _airJumpsUsed++;

        float takeOff = Mathf.Sqrt(2f * gravity * jumpHeight);
        _body.velocity = new Vector2(_body.velocity.x, takeOff);

        _bufferTimer = 0f;
        _coyoteTimer = 0f;
        _grounded = false;
        _jumpFiredThisStep = true;

        if (Jumped != null) Jumped();
    }

    void ApplyGravity()
    {
        float extra = 1f;
        if (_body.velocity.y < 0f) extra = fallGravityMultiplier;
        else if (_body.velocity.y > 0f && !_jumpHeld) extra = lowJumpGravityMultiplier;

        if (extra > 1f)
        {
            float gravity = Physics2D.gravity.y * _body.gravityScale;
            _body.velocity += new Vector2(0f, gravity * (extra - 1f) * Time.fixedDeltaTime);
        }

        if (maxFallSpeed > 0f && _body.velocity.y < -maxFallSpeed)
        {
            _body.velocity = new Vector2(_body.velocity.x, -maxFallSpeed);
        }
    }

    /// <summary>
    /// Overwrites the tuning fields from one preset object out of
    /// Presets/character-tuning-presets.json. Fields the JSON does not name
    /// keep their current value, so a preset can change only the two numbers
    /// an ice level needs.
    /// </summary>
    public void ApplyTuningJson(string json)
    {
        if (string.IsNullOrEmpty(json))
        {
            Debug.LogWarning("Character2DMotor: ApplyTuningJson was given an empty string, so nothing was changed.", this);
            return;
        }

        try
        {
            JsonUtility.FromJsonOverwrite(json, this);
        }
        catch (System.Exception error)
        {
            Debug.LogWarning("Character2DMotor: that preset is not valid JSON, so nothing was changed. Details: " + error.Message, this);
            return;
        }

        // JSON can carry values the Inspector would have refused. Clamp them.
        moveSpeed = Mathf.Max(0f, moveSpeed);
        jumpHeight = Mathf.Max(0f, jumpHeight);
        maxFallSpeed = Mathf.Max(0f, maxFallSpeed);
        extraAirJumps = Mathf.Max(0, extraAirJumps);
    }

    void OnDrawGizmosSelected()
    {
        Collider2D shape = GetComponent<Collider2D>();
        if (shape == null) return;

        Bounds bounds = shape.bounds;
        Vector3 centre = new Vector3(bounds.center.x, bounds.min.y - groundProbeThickness * 0.5f, 0f);
        Vector3 size = new Vector3(Mathf.Max(0.01f, bounds.size.x * 0.9f), Mathf.Max(0.01f, groundProbeThickness), 0f);
        Gizmos.color = Color.green;
        Gizmos.DrawWireCube(centre, size);
    }
}