【Unity 入門】【チュートリアル】2D アクションゲームを作る 10. 追尾するカメラ

目次

前回のチュートリアル

スクリプトの更新

「Scripts」フォルダを右クリックして「Create>C# Script」を設定します

作成したスクリプトに「CameraFollow」と名前を付けます
そして、各スクリプトファイルを開いて下記のコードを貼り付けて保存します

CameraFollow.cs

using UnityEngine;
using System.Collections;

public class CameraFollow : MonoBehaviour {

    public Controller2D target;
    public float verticalOffset;
    public float lookAheadDstX;
    public float lookSmoothTimeX;
    public float verticalSmoothTime;
    public Vector2 focusAreaSize;

    FocusArea focusArea;

    float currentLookAheadX;
    float targetLookAheadX;
    float lookAheadDirX;
    float smoothLookVelocityX;
    float smoothVelocityY;

    bool lookAheadStopped;

    void Start() {
        focusArea = new FocusArea (target.collider.bounds, focusAreaSize);
    }

    void LateUpdate() {
        focusArea.Update (target.collider.bounds);

        Vector2 focusPosition = focusArea.centre + Vector2.up * verticalOffset;

        if (focusArea.velocity.x != 0) {
            lookAheadDirX = Mathf.Sign (focusArea.velocity.x);
            if (Mathf.Sign(target.playerInput.x) == Mathf.Sign(focusArea.velocity.x) && target.playerInput.x != 0) {
                lookAheadStopped = false;
                targetLookAheadX = lookAheadDirX * lookAheadDstX;
            }
            else {
                if (!lookAheadStopped) {
                    lookAheadStopped = true;
                    targetLookAheadX = currentLookAheadX + (lookAheadDirX * lookAheadDstX - currentLookAheadX)/4f;
                }
            }
        }


        currentLookAheadX = Mathf.SmoothDamp (currentLookAheadX, targetLookAheadX, ref smoothLookVelocityX, lookSmoothTimeX);

        focusPosition.y = Mathf.SmoothDamp (transform.position.y, focusPosition.y, ref smoothVelocityY, verticalSmoothTime);
        focusPosition += Vector2.right * currentLookAheadX;
        transform.position = (Vector3)focusPosition + Vector3.forward * -10;
    }

    void OnDrawGizmos() {
        Gizmos.color = new Color (1, 0, 0, .5f);
        Gizmos.DrawCube (focusArea.centre, focusAreaSize);
    }

    struct FocusArea {
        public Vector2 centre;
        public Vector2 velocity;
        float left,right;
        float top,bottom;


        public FocusArea(Bounds targetBounds, Vector2 size) {
            left = targetBounds.center.x - size.x/2;
            right = targetBounds.center.x + size.x/2;
            bottom = targetBounds.min.y;
            top = targetBounds.min.y + size.y;

            velocity = Vector2.zero;
            centre = new Vector2((left+right)/2,(top +bottom)/2);
        }

        public void Update(Bounds targetBounds) {
            float shiftX = 0;
            if (targetBounds.min.x < left) {
                shiftX = targetBounds.min.x - left;
            } else if (targetBounds.max.x > right) {
                shiftX = targetBounds.max.x - right;
            }
            left += shiftX;
            right += shiftX;

            float shiftY = 0;
            if (targetBounds.min.y < bottom) {
                shiftY = targetBounds.min.y - bottom;
            } else if (targetBounds.max.y > top) {
                shiftY = targetBounds.max.y - top;
            }
            top += shiftY;
            bottom += shiftY;
            centre = new Vector2((left+right)/2,(top +bottom)/2);
            velocity = new Vector2 (shiftX, shiftY);
        }
    }

}

Controller2D.cs

using UnityEngine;
using System.Collections;

public class Controller2D : RaycastController {
    
    float maxClimbAngle = 80;
    float maxDescendAngle = 80;
    
    public CollisionInfo collisions;
    [HideInInspector]
    public Vector2 playerInput;
    
    public override void Start() {
        base.Start ();
        collisions.faceDir = 1;

    }
    
    public void Move(Vector3 velocity, bool standingOnPlatform) {
        Move (velocity, Vector2.zero, standingOnPlatform);
    }

    public void Move(Vector3 velocity, Vector2 input, bool standingOnPlatform = false) {
        UpdateRaycastOrigins ();
        collisions.Reset ();
        collisions.velocityOld = velocity;
        playerInput = input;

        if (velocity.x != 0) {
            collisions.faceDir = (int)Mathf.Sign(velocity.x);
        }

        if (velocity.y < 0) {
            DescendSlope(ref velocity);
        }

        HorizontalCollisions (ref velocity);
        if (velocity.y != 0) {
            VerticalCollisions (ref velocity);
        }

        transform.Translate (velocity);

        if (standingOnPlatform) {
            collisions.below = true;
        }
    }

    void HorizontalCollisions(ref Vector3 velocity) {
        float directionX = collisions.faceDir;
        float rayLength = Mathf.Abs (velocity.x) + skinWidth;

        if (Mathf.Abs(velocity.x) < skinWidth) {
            rayLength = 2*skinWidth;
        }
        
        for (int i = 0; i < horizontalRayCount; i ++) {
            Vector2 rayOrigin = (directionX == -1)?raycastOrigins.bottomLeft:raycastOrigins.bottomRight;
            rayOrigin += Vector2.up * (horizontalRaySpacing * i);
            RaycastHit2D hit = Physics2D.Raycast(rayOrigin, Vector2.right * directionX, rayLength, collisionMask);

            Debug.DrawRay(rayOrigin, Vector2.right * directionX * rayLength,Color.red);

            if (hit) {

                if (hit.distance == 0) {
                    continue;
                }
            
                float slopeAngle = Vector2.Angle(hit.normal, Vector2.up);

                if (i == 0 && slopeAngle <= maxClimbAngle) {
                    if (collisions.descendingSlope) {
                        collisions.descendingSlope = false;
                        velocity = collisions.velocityOld;
                    }
                    float distanceToSlopeStart = 0;
                    if (slopeAngle != collisions.slopeAngleOld) {
                        distanceToSlopeStart = hit.distance-skinWidth;
                        velocity.x -= distanceToSlopeStart * directionX;
                    }
                    ClimbSlope(ref velocity, slopeAngle);
                    velocity.x += distanceToSlopeStart * directionX;
                }

                if (!collisions.climbingSlope || slopeAngle > maxClimbAngle) {
                    velocity.x = (hit.distance - skinWidth) * directionX;
                    rayLength = hit.distance;

                    if (collisions.climbingSlope) {
                        velocity.y = Mathf.Tan(collisions.slopeAngle * Mathf.Deg2Rad) * Mathf.Abs(velocity.x);
                    }

                    collisions.left = directionX == -1;
                    collisions.right = directionX == 1;
                }
            }
        }
    }
    
    void VerticalCollisions(ref Vector3 velocity) {
        float directionY = Mathf.Sign (velocity.y);
        float rayLength = Mathf.Abs (velocity.y) + skinWidth;

        for (int i = 0; i < verticalRayCount; i ++) {

            Vector2 rayOrigin = (directionY == -1)?raycastOrigins.bottomLeft:raycastOrigins.topLeft;
            rayOrigin += Vector2.right * (verticalRaySpacing * i + velocity.x);
            RaycastHit2D hit = Physics2D.Raycast(rayOrigin, Vector2.up * directionY, rayLength, collisionMask);

            Debug.DrawRay(rayOrigin, Vector2.up * directionY * rayLength,Color.red);

            if (hit) {
                if (hit.collider.tag == "Through") {
                    if (directionY == 1 || hit.distance == 0) {
                        continue;
                    }
                    if (collisions.fallingThroughPlatform) {
                        continue;
                    }
                    if (playerInput.y == -1) {
                        collisions.fallingThroughPlatform = true;
                        Invoke("ResetFallingThroughPlatform",.5f);
                        continue;
                    }
                }

                velocity.y = (hit.distance - skinWidth) * directionY;
                rayLength = hit.distance;

                if (collisions.climbingSlope) {
                    velocity.x = velocity.y / Mathf.Tan(collisions.slopeAngle * Mathf.Deg2Rad) * Mathf.Sign(velocity.x);
                }

                collisions.below = directionY == -1;
                collisions.above = directionY == 1;
            }
        }

        if (collisions.climbingSlope) {
            float directionX = Mathf.Sign(velocity.x);
            rayLength = Mathf.Abs(velocity.x) + skinWidth;
            Vector2 rayOrigin = ((directionX == -1)?raycastOrigins.bottomLeft:raycastOrigins.bottomRight) + Vector2.up * velocity.y;
            RaycastHit2D hit = Physics2D.Raycast(rayOrigin,Vector2.right * directionX,rayLength,collisionMask);

            if (hit) {
                float slopeAngle = Vector2.Angle(hit.normal,Vector2.up);
                if (slopeAngle != collisions.slopeAngle) {
                    velocity.x = (hit.distance - skinWidth) * directionX;
                    collisions.slopeAngle = slopeAngle;
                }
            }
        }
    }

    void ClimbSlope(ref Vector3 velocity, float slopeAngle) {
        float moveDistance = Mathf.Abs (velocity.x);
        float climbVelocityY = Mathf.Sin (slopeAngle * Mathf.Deg2Rad) * moveDistance;

        if (velocity.y <= climbVelocityY) {
            velocity.y = climbVelocityY;
            velocity.x = Mathf.Cos (slopeAngle * Mathf.Deg2Rad) * moveDistance * Mathf.Sign (velocity.x);
            collisions.below = true;
            collisions.climbingSlope = true;
            collisions.slopeAngle = slopeAngle;
        }
    }

    void DescendSlope(ref Vector3 velocity) {
        float directionX = Mathf.Sign (velocity.x);
        Vector2 rayOrigin = (directionX == -1) ? raycastOrigins.bottomRight : raycastOrigins.bottomLeft;
        RaycastHit2D hit = Physics2D.Raycast (rayOrigin, -Vector2.up, Mathf.Infinity, collisionMask);

        if (hit) {
            float slopeAngle = Vector2.Angle(hit.normal, Vector2.up);
            if (slopeAngle != 0 && slopeAngle <= maxDescendAngle) {
                if (Mathf.Sign(hit.normal.x) == directionX) {
                    if (hit.distance - skinWidth <= Mathf.Tan(slopeAngle * Mathf.Deg2Rad) * Mathf.Abs(velocity.x)) {
                        float moveDistance = Mathf.Abs(velocity.x);
                        float descendVelocityY = Mathf.Sin (slopeAngle * Mathf.Deg2Rad) * moveDistance;
                        velocity.x = Mathf.Cos (slopeAngle * Mathf.Deg2Rad) * moveDistance * Mathf.Sign (velocity.x);
                        velocity.y -= descendVelocityY;

                        collisions.slopeAngle = slopeAngle;
                        collisions.descendingSlope = true;
                        collisions.below = true;
                    }
                }
            }
        }
    }

    void ResetFallingThroughPlatform() {
        collisions.fallingThroughPlatform = false;
    }

    public struct CollisionInfo {
        public bool above, below;
        public bool left, right;

        public bool climbingSlope;
        public bool descendingSlope;
        public float slopeAngle, slopeAngleOld;
        public Vector3 velocityOld;
        public int faceDir;
        public bool fallingThroughPlatform;

        public void Reset() {
            above = below = false;
            left = right = false;
            climbingSlope = false;
            descendingSlope = false;

            slopeAngleOld = slopeAngle;
            slopeAngle = 0;
        }
    }

}

RaycastController.cs

using UnityEngine;
using System.Collections;

[RequireComponent (typeof (BoxCollider2D))]
public class RaycastController : MonoBehaviour {

    public LayerMask collisionMask;
    
    public const float skinWidth = .015f;
    public int horizontalRayCount = 4;
    public int verticalRayCount = 4;

    [HideInInspector]
    public float horizontalRaySpacing;
    [HideInInspector]
    public float verticalRaySpacing;

    [HideInInspector]
    public BoxCollider2D collider;
    public RaycastOrigins raycastOrigins;

    public virtual void Awake() {
        collider = GetComponent<BoxCollider2D> ();
    }

    public virtual void Start() {
        CalculateRaySpacing ();
    }

    public void UpdateRaycastOrigins() {
        Bounds bounds = collider.bounds;
        bounds.Expand (skinWidth * -2);
        
        raycastOrigins.bottomLeft = new Vector2 (bounds.min.x, bounds.min.y);
        raycastOrigins.bottomRight = new Vector2 (bounds.max.x, bounds.min.y);
        raycastOrigins.topLeft = new Vector2 (bounds.min.x, bounds.max.y);
        raycastOrigins.topRight = new Vector2 (bounds.max.x, bounds.max.y);
    }
    
    public void CalculateRaySpacing() {
        Bounds bounds = collider.bounds;
        bounds.Expand (skinWidth * -2);
        
        horizontalRayCount = Mathf.Clamp (horizontalRayCount, 2, int.MaxValue);
        verticalRayCount = Mathf.Clamp (verticalRayCount, 2, int.MaxValue);
        
        horizontalRaySpacing = bounds.size.y / (horizontalRayCount - 1);
        verticalRaySpacing = bounds.size.x / (verticalRayCount - 1);
    }
    
    public struct RaycastOrigins {
        public Vector2 topLeft, topRight;
        public Vector2 bottomLeft, bottomRight;
    }
}

カメラの設定

作成した「CameraFollow」スクリプトを「Main Camera」オブジェクトにドラッグします

そして、「Main Camera」オブジェクトを選択した状態で

「Target」の欄に「Player」オブジェクトをドラッグします

最後に、これらのパラメータに上記のように値を設定します

後は、シーンに適当に床や壁を配置してゲームを再生すると、
プレイヤーにカメラが追尾するようになっていることが確認できます

次のチュートリアル