Transforms position from world space to local space. The opposite of Transform.TransformPoint.

Note that the returned position is affected by scale. Use Transform.InverseTransformDirection if you are dealing with directions.

	// Calculate the transform's position relative to the camera.
	var cam = Camera.main.transform;
	var cameraRelative = cam.InverseTransformPoint(transform.position);
	if (cameraRelative.z > 0)
		print ("The object is in front of the camera");
	else
		print ("The object is behind the camera");

using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    public Transform cam = Camera.main.transform;
    public Vector3 cameraRelative = cam.InverseTransformPoint(transform.position);
    void Example() {
        if (cameraRelative.z > 0)
            print("The object is in front of the camera");
        else
            print("The object is behind the camera");
    }
}

import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	public cam as Transform = Camera.main.transform

	public cameraRelative as Vector3 = cam.InverseTransformPoint(transform.position)

	def Example() as void:
		if cameraRelative.z > 0:
			print('The object is in front of the camera')
		else:
			print('The object is behind the camera')

Transforms the position x, y, z from world space to local space. The opposite of Transform.TransformPoint.

Note that the returned position is affected by scale. Use Transform.InverseTransformDirection if you are dealing with directions.

	// Calculate the world origin relative to this transform.
	relativePoint = transform.InverseTransformPoint(0, 0, 0);
	if (relativePoint.z > 0)
		print ("The world origin is in front of this object");
	else
		print ("The world origin is behind of this object");

using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    void Example() {
        relativePoint = transform.InverseTransformPoint(0, 0, 0);
        if (relativePoint.z > 0)
            print("The world origin is in front of this object");
        else
            print("The world origin is behind of this object");
    }
}

import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	def Example() as void:
		relativePoint = transform.InverseTransformPoint(0, 0, 0)
		if relativePoint.z > 0:
			print('The world origin is in front of this object')
		else:
			print('The world origin is behind of this object')