Is the collider a trigger?
A trigger doesn't collide with rigid bodies. Instead it sends OnTriggerEnter, OnTriggerExit and OnTriggerStay message when a rigidbody enters or exits the trigger.
// Turns the attached to collider into a trigger. collider.isTrigger = true;
using UnityEngine; using System.Collections; public class ExampleClass : MonoBehaviour { void Example() { collider.isTrigger = true; } }
import UnityEngine import System.Collections public class ExampleClass(MonoBehaviour): def Example() as void: collider.isTrigger = true