Try & Error

Unity 2021.3.44f1

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Unity Editor의 Scene View에서 Camera의 View Frustum을 볼 수 있게 해주는 스크립트.

View Frustum을 보고 싶은 카메라에 Component로 넣고 실행하면 Scene View에 보인다.

using UnityEngine;

public class FrustumViewer : MonoBehaviour
{
// 에디터에서만 작동하도록 define
#if UNITY_EDITOR

    Camera m_Camera = null;
    Vector3[] m_nearCorners = new Vector3[4]; //Approx'd nearplane corners
    Vector3[] m_farCorners = new Vector3[4]; //Approx'd farplane corners
    Plane[] m_camPlanes = null;


    private void OnEnable()
    {
        m_Camera = this.GetComponent<Camera>();
    }

    void Update()
    {
        DrawFrustum(m_Camera);
    }

    void DrawFrustum(Camera _cam)
    {
        if (null == _cam)
            return;

        m_camPlanes = GeometryUtility.CalculateFrustumPlanes(_cam); //get planes from matrix

        Plane temp = m_camPlanes[1]; m_camPlanes[1] = m_camPlanes[2]; m_camPlanes[2] = temp; //swap [1] and [2] so the order is better for the loop
        for (int i = 0; i < 4; i++)
        {
            m_nearCorners[i] = Plane3Intersect(m_camPlanes[4], m_camPlanes[i], m_camPlanes[(i + 1) % 4]); //near corners on the created projection matrix
            m_farCorners[i] = Plane3Intersect(m_camPlanes[5], m_camPlanes[i], m_camPlanes[(i + 1) % 4]); //far corners on the created projection matrix
        }

        for (int i = 0; i < 4; i++)
        {
            Debug.DrawLine(m_nearCorners[i], m_nearCorners[(i + 1) % 4], Color.red, Time.deltaTime, true); //near corners on the created projection matrix
            Debug.DrawLine(m_farCorners[i], m_farCorners[(i + 1) % 4], Color.blue, Time.deltaTime, true); //far corners on the created projection matrix
            Debug.DrawLine(m_nearCorners[i], m_farCorners[i], Color.green, Time.deltaTime, true); //sides of the created projection matrix
        }
    }



    Vector3 Plane3Intersect(Plane p1, Plane p2, Plane p3)
    { 
        //get the intersection point of 3 planes
        return ((-p1.distance * Vector3.Cross(p2.normal, p3.normal)) +
                (-p2.distance * Vector3.Cross(p3.normal, p1.normal)) +
                (-p3.distance * Vector3.Cross(p1.normal, p2.normal))) /
                (Vector3.Dot(p1.normal, Vector3.Cross(p2.normal, p3.normal)));
    }

#endif
}

[참조] https://grrava.blogspot.com/2014/04/render-view-frustrum-of-camera-in-unity.html