CaluclatePath without NavAgent

        //----------------------------------------------------------------------------------------
        private static NavMeshPath CalculatePath(Vector3 _from, Vector3 _to, int _navigationLayer, int _agentType, int _areaMask)
        {
            var navMeshQueryFilter = new NavMeshQueryFilter();
            var navMeshPath = new NavMeshPath();

            // also set area cost here if you have
            //m_navMeshQueryFilter.SetAreaCost(_layer, _costsForLayer);
            navMeshQueryFilter.agentTypeID = _agentType;
            navMeshQueryFilter.areaMask = _areaMask;

            NavMeshHit hitStart, hitEnd;
            var ok = NavMesh.SamplePosition(_from, out hitStart, 10.0f, _navigationLayer);
            ok &= NavMesh.SamplePosition(_to, out hitEnd, 10.0f, _navigationLayer);
            if (ok == false)
                return null;

            var reachable = NavMesh.CalculatePath(hitStart.position, hitEnd.position, m_navMeshQueryFilter, navMeshPath);
            if (reachable == false)
                return null;

            return navMeshPath;
        }