Navmesh utils - GetRandomPointInRadius , CalculatePathLength

NavMeshUtil.cs

using UnityEngine.AI;
using UnityEngine;

namespace pro.datagreed.utils
{
    public static class NavMeshUtil
    {

        // Get Random Point on a Navmesh surface in the specified radius
        public static Vector3 GetRandomPointInRadius(Vector3 center, float maxDistance)
        {
            // Get Random Point inside Sphere which position is center, radius is maxDistance
            Vector3 randomPos = Random.insideUnitSphere * maxDistance + center;

            NavMeshHit hit; // NavMesh Sampling Info Container

            // from randomPos find a nearest point on NavMesh surface in range of maxDistance
            NavMesh.SamplePosition(randomPos, out hit, maxDistance, NavMesh.AllAreas);

            return hit.position;
        }

        /// <summary>
        /// Calculates walking path length between two points on a navmesh.
        /// Useful for checking e.g. how long the sound should travel to attract attention of
        /// the enemy
        /// based on https://www.youtube.com/watch?v=mBGUY7EUxXQ&ab_channel=Unity
        /// </summary>
        /// <param name="sourcePosition"></param>
        /// <param name="targetPosition"></param>
        /// <param name="areaMask"></param>
        /// <returns></returns>
        public static float CalculatePathLength(Vector3 sourcePosition, Vector3 targetPosition, int areaMask=NavMesh.AllAreas) 
        { 
            //based on https://www.youtube.com/watch?v=mBGUY7EUxXQ&ab_channel=Unity
            NavMeshPath path = new NavMeshPath();
            // if (nav.enabled)
            // {
            // nav.CalculatePath(targetPosition, path);
            // }
            NavMesh.CalculatePath(sourcePosition, targetPosition, areaMask, path);
            
            Vector3[] allWayPoints = new Vector3[path.corners.Length+2]; 
            
            //add source and destination points, so we can measure the distance between them and nearest corners if any
            allWayPoints[0] = sourcePosition; 
            allWayPoints[allWayPoints.Length-1] = targetPosition;
            
            for (int i = 0; i < path.corners.Length; i++)
            {
                allWayPoints[i+1] = path.corners[i]; 
            }

            float pathLength = 0f; 
            for(int i=0; i<allWayPoints.Length-1; i++) 
            { 
                pathLength+=Vector3.Distance(allWayPoints[i], allWayPoints[i+1]);
            }

            return pathLength; 
        } 
    }
}