Collider.ClosestPoint

Parameters

Returns

Vector3 The closest point on the collider, returned in world space coordinates.

Description

The closest point on the collider given a specified ___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 Collider.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.
// Note that closestPoint functions correctly regardless of whether the collider is set as a trigger.
//
// 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.