unity projection 프로젝션

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 [RequireComponent(typeof(Camera))]
 [ExecuteInEditMode]
 public class FrustumSetter : MonoBehaviour
 {
    Camera m_cam = null;
    [Range(0.001f,1)]
    public float near_minus = 1;
    [SerializeField]
    float m_nearFarDistance = 100;
    [SerializeField]
    GameObject m_monitorQuad = null;
    // Use this for initialization
    void Start()
    {
        m_cam = GetComponent<Camera>();
 
        if (m_monitorQuad != null)
        {
            Renderer r = m_monitorQuad.GetComponent<Renderer>();
            if (r != null)
            {
                r.enabled = false;
            }
        }
    }
    // Update is called once per frame
    void LateUpdate()
    {
        if (m_monitorQuad != null && m_cam != null)
        {
            SetFrustumFromQuad(m_cam, m_monitorQuad);
        }
    }
    void SetFrustumFromQuad(Camera cam, GameObject quad)
    {
        float m_left = -1;
        float m_right = 1;
        float m_top = 1;
        float m_bottom = -1;
        float m_near = 1;
        float m_far = 1000;
        // quads Z rotation (roll) is locked
        quad.transform.localEulerAngles = new Vector3(quad.transform.localEulerAngles.x, quad.transform.localEulerAngles.y, 0);
        // set near far plane
        m_near = GetDistanceFromQuad(cam, quad);
        cam.nearClipPlane = m_near * near_minus;
        m_far = m_near + m_nearFarDistance;
        cam.farClipPlane = m_far;
        // set camera rotation
        cam.transform.forward = m_monitorQuad.transform.forward;
        //set left right bottom top
        {
            Matrix4x4 worldToCamMat = cam.worldToCameraMatrix;
            Mesh quadMesh = quad.GetComponent<MeshFilter>().sharedMesh;

            //transform Quad corner-vertices position from local space to world space //03 or 21
            Vector3 vertexLeftBottom = quad.transform.localToWorldMatrix.MultiplyPoint(quadMesh.vertices[0]);
            Vector3 vertexRightTop = quad.transform.localToWorldMatrix.MultiplyPoint(quadMesh.vertices[3]);

            //transform from world space to camera space
            Vector3 leftBottom = worldToCamMat.MultiplyPoint(vertexLeftBottom);
            Vector3 rightTop = worldToCamMat.MultiplyPoint(vertexRightTop);

            m_left = leftBottom.x;
            m_bottom = leftBottom.y;
            m_right = rightTop.x;
            m_top = rightTop.y;
        }
        //set projection matrix
        cam.projectionMatrix = Matrix4x4.Frustum(m_left, m_right, m_bottom, m_top, m_near, m_far);
        //original (m_location)
        float s_near = RotioCalculate(0, m_near, near_minus);
        float s_left = RotioCalculate(0, m_left, near_minus);
        float s_right = RotioCalculate(0, m_right, near_minus);
        float s_bottom = RotioCalculate(0, m_bottom, near_minus);
        float s_top = RotioCalculate(0, m_top, near_minus);
        cam.projectionMatrix = Matrix4x4.Frustum(s_left, s_right, s_bottom, s_top, s_near, m_far);
    }
    float GetDistanceFromQuad(Camera cam, GameObject quad)
    {
        Vector3 qNormal = quad.transform.forward.normalized;
        Vector3 qPos = cam.transform.position - quad.transform.position;
        float distance = Mathf.Abs(Vector3.Dot(qNormal, qPos));
        //float distance = Vector3.Distance(cam.transform.position, quad.transform.position);
        return distance;
    }
    float RotioCalculate(float start, float end, float ratio)
    {
        return start+(end*ratio);
    }
 }