Build dynamically a plane mesh from its 4 corners position in world and displaying an image filling the plane .

ImagePlane.cs

using FuretCompany.Utils;
using UnityEngine;

public class ImagePlane : MonoBehaviour
{
    public string imageResourceName;
    protected Vector3 _topLeft;
    public Vector3 topLeft { get { return _topLeft; } set { if (value != _topLeft) { _topLeft = value; _meshDirty = true; } } }
    protected Vector3 _topRight;
    public Vector3 topRight { get { return _topRight; } set { if (value != _topRight) { _topRight = value; _meshDirty = true; } } }
    protected Vector3 _bottomRight;
    public Vector3 bottomRight { get { return _bottomRight; } set { if (value != _bottomRight) { _bottomRight = value; _meshDirty = true; } } }
    protected Vector3 _bottomLeft;
    public Vector3 bottomLeft { get { return _bottomLeft; } set { if (value != _bottomLeft) { _bottomLeft = value; _meshDirty = true; } } }

    protected bool _meshDirty=false;

    protected MeshRenderer meshRenderer;
    protected Rigidbody rigidBody;
    protected MeshFilter meshFilter;
    //protected BoxCollider boxCollider;
    protected MeshCollider meshCollider;

    // Use this for initialization
    void Start() {
        if (AppManager.Instance.debugMode) Debug.Log("ImagePlane.Start " + imageResourceName + " topLeft=" + topLeft + " bottomRight=" + bottomRight);

        // Grab the mesh renderer that's on the same object as this script.
        //rigidBody =gameObject.AddComponent<Rigidbody>();
        meshFilter=gameObject.AddComponent<MeshFilter>();
        //boxCollider=gameObject.AddComponent<BoxCollider>();
        meshCollider = gameObject.AddComponent<MeshCollider>();
        meshRenderer =gameObject.AddComponent<MeshRenderer>();

        meshFilter.mesh = CreateMesh();
        _meshDirty = false;
        meshCollider.sharedMesh = meshFilter.mesh;
        meshCollider.convex = true;
        meshCollider.inflateMesh = true;




        meshRenderer.material.shader = Shader.Find("Particles/Additive");
        Texture2D tex;
        tex = Tools.LoadPNG(imageResourceName);
        if (tex==null) tex = new Texture2D(1, 1);
        tex.SetPixel(0, 0, Color.green);
        tex.Apply();
        meshRenderer.material.mainTexture = tex;
        meshRenderer.material.color = Color.green;

    }

    void UpdateMesh()
    {
        meshFilter.mesh.vertices = new Vector3[] {
            bottomLeft,
            bottomRight,
            topRight,
            topLeft
        };
        meshFilter.mesh.RecalculateBounds();
        meshCollider.sharedMesh = null;
        meshCollider.sharedMesh = meshFilter.mesh;
        //boxCollider.center = meshRenderer.bounds.center;
        //boxCollider.size = meshRenderer.bounds.size;
        _meshDirty = false;
        //Debug.Log("UpdateMesh topLeft="+ topLeft+ " bottomRight=" + bottomRight);
    }

    Mesh CreateMesh()
    {
        Mesh m = new Mesh();
        m.name = "ImagePlaneMesh";
        m.vertices = new Vector3[] {
            bottomLeft,
            bottomRight,
            topRight,
            topLeft
        };
        m.uv = new Vector2[] {
            new Vector2 (0, 0),
            new Vector2 (1, 0),
            new Vector2(1, 1),
            new Vector2 (0,1)
        };
        m.triangles = new int[] { 0, 1, 2, 0, 2, 3 };
        m.RecalculateNormals();

        return m;
    }

    // Update is called once per frame
    void Update() {
        if (_meshDirty)
        {
            UpdateMesh();
        }
    }
}