Collider.ClosestPoint

Parameters

Returns

Vector3 The point on the collider that is closest to the specified location.

Description

Returns a point on the collider that is closest to a given location.

This method computes the point on the Collider that is closest to a 3D location in the world. In the example below closestPoint is the point on the Collider and location is the point in 3D space. If location is in the Collider the closestPoint is inside. If the Collider is disabled, the method returns the input position.

Note: The difference from ClosestPointOnBounds is that the returned point is actually on the collider instead of on the bounds of the collider. (bounds is a box that surrounds the collider.)

using UnityEngine;

// Note that closestPoint is based on the surface of the collider
// and location represents a point in 3d space.
// The gizmos work in the editor.
//
// Create an origin-based cube and give it a scale of (1, 0.5, 3).
// Change the BoxCollider size to (0.8, 1.2, 0.8).  This means that
// collisions will happen when a GameObject gets close to the BoxCollider.
// The ShowClosestPoint.cs script shows spheres that display the location
// and closestPoint.  Try changing the BoxCollider size and the location
// values.

// Attach this to a GameObject that has a Collider component attached
public class ShowClosestPoint : MonoBehaviour
{
    public Vector3 location;

    public void OnDrawGizmos()
    {
        var collider = GetComponent<Collider>();

        if (!collider)
        {
            return; // nothing to do without a collider
        }

        Vector3 closestPoint = collider.ClosestPoint(location);

        Gizmos.DrawSphere(location, 0.1f);
        Gizmos.DrawWireSphere(closestPoint, 0.1f);
    }
}

Note: Same as Physics.ClosestPoint but doesn't allow passing a custom position and rotation. Instead, it uses the position of the collider.