Camera.WorldToScreenPoint

설명

Transforms position from world space into screen space.

Screenspace is defined in pixels. The bottom-left of the screen is (0,0); the right-top is (pixelWidth,pixelHeight). The z position is in world units from the camera.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    public Transform target;
    Camera camera;
    
    void Start() {
    	camera = GetComponent<Camera>();
    }
    
    void Update() {
        Vector3 screenPos = camera.WorldToScreenPoint(target.position);
        Debug.Log("target is " + screenPos.x + " pixels from the left");
    }
}