Rigidbody.ClosestPointOnBounds

function ClosestPointOnBounds (position : Vector3) : Vector3

Description

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

JavaScript
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

class example(MonoBehaviour):

public hitPoints as single = 10.0F

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