The closest point to the bounding box of the attached colliders.

This can be used to calculate hit points when applying explosion damage. Or calculating explosion forces that act on a point on the surface of the rigidbody.

	var hitPoints : float = 10.0;
	function ApplyHitPoints (explosionPos : Vector3, radius : float) {
		// The distance from the explosion position to the surface of the rigidbody
		var closestPoint : Vector3 = rigidbody.ClosestPointOnBounds(explosionPos);
		var distance : float = Vector3.Distance(closestPoint, explosionPos);
		// The hit points we apply fall decrease with distance from the hit point
		var damage : float  = 1.0 - Mathf.Clamp01(distance / radius);
		
		// This is the final hitpoints we want to apply. 10 at maximum.
		damage *= 10;
		
		// Apply the damage
		hitPoints -= damage;
	}

using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    public float hitPoints = 10.0F;
    void ApplyHitPoints(Vector3 explosionPos, float radius) {
        Vector3 closestPoint = rigidbody.ClosestPointOnBounds(explosionPos);
        float distance = Vector3.Distance(closestPoint, explosionPos);
        float damage = 1.0F - Mathf.Clamp01(distance / radius);
        damage *= 10;
        hitPoints -= damage;
    }
}

import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	public hitPoints as float = 10.0F

	def ApplyHitPoints(explosionPos as Vector3, radius as float) as void:
		closestPoint as Vector3 = rigidbody.ClosestPointOnBounds(explosionPos)
		distance as float = Vector3.Distance(closestPoint, explosionPos)
		damage as float = (1.0F - Mathf.Clamp01((distance / radius)))
		damage *= 10
		hitPoints -= damage