Version: 2017.3
public static void DrawRay (Ray r);
public static void DrawRay (Vector3 from, Vector3 direction);

説明

from から from + direction に向けてレイを描画します

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour { void OnDrawGizmosSelected() { Gizmos.color = Color.red; Vector3 direction = transform.TransformDirection(Vector3.forward) * 5; Gizmos.DrawRay(transform.position, direction); } }