MonoBehaviour.OnRenderObject()

Description

OnRenderObject вызывается после того, как камера отрендерила сцену.

This can be used to render your own objects using Graphics.DrawMeshNow or other functions. This function is similar to OnPostRender, except OnRenderObject is called on any object that has a script with the function; no matter if it's attached to a Camera or not.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    public Mesh mainMesh;
    public Mesh miniMapMesh;
    void OnRenderObject() {
        if (Camera.current.name == "MiniMapcam")
            Graphics.DrawMeshNow(miniMapMesh, transform.position, transform.rotation);
        else
            Graphics.DrawMeshNow(mainMesh, transform.position, transform.rotation);
    }
}