Calculate Path Cost

        //----------------------------------------------------------------------------------------
        public static float CalculatePathCost(Vector3[] _pathCorners, int _pathLength, NavMeshQueryFilter _queryFilter)
        {
            float cost = 0;
            NavMeshHit hit;
            NavMesh.SamplePosition(_pathCorners[0], out hit, 0.1f, NavMesh.AllAreas);
            var rayStart = _pathCorners[0];
            var mask = hit.mask;
            var areaIndex = IndexFromMask(mask);

            for (var index = 1; index < _pathLength; ++index)
            {
                var maxTries = 5;
                do
                {
                    var corner = _pathCorners[index];
                    if (NavMesh.Raycast(rayStart, corner, out hit, mask))
                    {
                        cost += _queryFilter.GetAreaCost(areaIndex) * hit.distance;
                        if (hit.mask != 0)
                            mask = hit.mask;
                        areaIndex = IndexFromMask(mask);
                        rayStart = hit.position;

                        if (hit.mask == 0)
                            rayStart += (corner - rayStart).normalized * 0.05f;
                    }
                    else
                    {
                        rayStart += (corner - rayStart).normalized * 0.05f;
                    }

                    maxTries--;
                } while (hit.hit && maxTries > 0);
            }
            return cost;
        }