The accurate representation of the domain boundary is usually a critical feature in the context of computational mechanics simulations, and specifically within immersed boundary methods where the mesh is generated independently of the geometry. Unlike standard finite element approaches, these methods require the geometry model —which is typically defined by NURBS— to play a central role in core numerical processes, including element classification, integration rule design, and the imposition of boundary conditions. Nowadays, the available libraries for NURBS manipulation often lack the specific interaction tools required for simulation or rely on rigid data structures that hinder computational performance and integration of the NURBS in the simulation algorithms. To address these limitations, this work presents NURBSLab [1], a comprehensive library developed from scratch in MATLAB, designed to manipulate and utilize NURBS surfaces efficiently within high-fidelity analysis frameworks. A key distinguishing feature of the proposed tool is its generalist design philosophy: it avoids restrictive object-oriented structures and works directly with control points and knot vectors. This allows for seamless integration into existing FEM codes without requiring data duplication or translation layers. The library gathers a wide range of functionalities beyond simple generation, including sampling, decomposition, reparameterization, and crucially, robust algorithms for projection and intersection calculation. The capabilities of the tool are demonstrated through its application in the Cartesian Grid Discontinuous Galerkin (cgDG) framework [2], proving its efficacy in handling complex geometry-mesh interactions and providing a broadly applicable resource for the computational mechanics community. ACKNOWLEDGEMENTS The authors gratefully acknowledge the financial support of: Grant MCIN/AEI/10.13039/501100011033 funded by ”Ministerio de Ciencia e Innovación”. Grant PID2022-141512NB-I00 funded by ”Fondo Europeo de Desarrollo Regional -FEDER-”. Grant FPU17/03993 funded by ”Ministerio de Universidades”. REFERENCES [1] Navarro-Garcíıa H (2026). NURBSLab (https://es.mathworks.com/matlabcentral/fileexchange/183181-nurbslab), MATLAB Central File Exchange [2] Navarro-García H, Sevilla R, Nadal E, Ródenas JJ. High-order discontinuous Galerkin method for time-domain electromagnetics on geometry-independent Cartesian meshes, Int J Numer Methods Eng., 122(24), 7632-7663, 2021.