nTop Models
This is a collection of some of my favorite parametric models that I’ve made in nTop. These models are all 100% or nearly 100% designed in nTop, with a focus on parameterization and speed. Hopefully these serve as some inspiration as to the types of things that are possible with procedural implicit modeling.
Blisk
Creating equation-driven geometry can be very slow and difficult with b-reps, especially if it needs to be integrated into a highly parametric, automated design. The wonderful thing about implicit models is that spatially varying functions and geometry tie together seamlessly. Custom spatial functions, helpful implicit modeling tools, and a procedural modeling paradigm mean you can create a design to be wrapped in an MDO workflow without the risk of a geometry bottleneck.
I wanted to try implementing this “blisk” design from scratch in nTop based on a paper that Trevor Laughlin shared with me. The authors analytically calculate efficiency for life cycle analysis while balancing against manufacturability. It features some standard prismatic features, a DCA airfoil, precise blends, and spatially varying parameters such as camber, twist, chord length, and a swept tip. The twist, for example, is driven by a simplified version of Navier-Stokes.
Implicit modeling is famous for lattices and “unbreakable” booleans, but that’s not where the story ends.
Here’s the paper: Fricke, K., et al. (2021). Geometry Model and Approach for Future Blisk LCA. IOP Conf. Ser.: Mater. Sci. Eng., 1024, 012067.
Liquid-fueled rocket
“wtf” is the reaction this type of parametric modeling demo tends to get, because people still aren’t used to seeing models this robust (let alone update in real time).
This model is 100% nTop and 100% parametric. It’s built with the curve modeling functions we introduced earlier this year (for detailed profile control) and implicits (for bulletproof model updates). It can be analyzed in nTop, connected to analysis packages or CAD tools, or exported for manufacturing. It lets you explore a massive entire design space extremely quickly (including huge configuration changes like the number of control surfaces).
The rotation planes of the control surfaces automatically avoid the changing shape of the fuselage and the actuators follow. The blends automatically update, and the inner structures morph along with everything else. Airfoils can be swapped out by dragging and dropping, and so can the governing shape of the fuselage.
As a bonus, here is a closer look at some actuating fins that were the final touch to win some strategic deals.
Aircraft OMLs (CCA + Fighter Jet)
These two models became the backbone of nTop’s front-line presentations in the shift to A&D in 2025. They have been the subject of webinars and leading examples in executive-led presentations to key customers.
Parametric Impeller
Implicit modeling is about a lot more than just lattices (as much as I love lattices). Highly parametric designs can be updated nearly instantly with no risk of small topological changes breaking the workflow. Derivatives can be accessed quickly for gradient-based parameter optimization within a broader engineering system.
I had a lot of fun making this parametric impeller completely in nTop. This particular design has 16 parameters exposed, which could be reconfigured depending on the design study. If I save it to a .implicit file, each variant is just 61KB!
NACA Airfoil Wing with Ribs and Spars
ComputationalDesign is all about fast iterations. It’s about taking design intent and engineering first principles and encoding them into a design that can be iterated hundreds or thousands of times. #implicitmodeling is like a super power that makes these things possible without having to worry about broken model trees and surface-surface intersections.
In this latest nTop-only model, I have a wing with a spatially driven NACA airfoil profile. The special part is that airfoil profile comes directly from the NACA airfoil equations and is completely spatially varying. This means the four digit code, scale, and attack angle can change along the wing (and are not just stretched and distorted!). The ribs and spars are automatically created too, with all their own parameters, and slot together for prototyping. We can even integrate lift and drag coefficients over the whole wing to estimate overall performance (not to mention the derivative information we can access).
I love this example because it’s a clear case of encoding design rules directly into a computational model. We’re working hard at nTop to make implicit modeling and building computational models easier next year, so I can’t wait to see what other cool applications people come up with. ✈️
Variable Nozzle
For the same reason implicit modeling excels at lattices, it can create complex arrays and patterns at virtually no extra cost. We’re talking arrays of tens, hundreds, thousands, or more (and not just identical ones). The output can be combined with other geometry and modified as any other object would be. Design parameters (not just offsets!) can even be varied throughout space within the array while maintaining the same computation speed. #implicitmodeling is changing what geometric complexity in CAD means and I can’t wait to help push the frontier further.
I decided to start making this simplified scale model of an adjustable exhaust nozzle as an experiment, in nTop, from scratch. It’s inspired by the F-15 design and I’ve had a super fun time building it out. The current iteration is fully parametric, meshes super fast, and even includes a basic encoding of the main linkage with two angle inputs. This way, we can run (meshless!) CFD on it in different configurations. If I want to export it to other software, I have several options, and the .implicit file is just 123kB.