Nvidia has launched USD BRep, a geometry kernel for NURBS-based boundary representation (BRep) solid modelling, sparking a rush from developers to create open source CAD modelling software developed to greater use AI tools and workflows.
USD BRep is a standalone C++ and Python library for NURBS-based boundary representation (BRep) solid modelling.
Despite steps made in recent months, AI-to-CAD has suffered due to the issues training machine learning algorithms on traditional CAD data, its metadata and multi-step feature trees. As the new USD BRep kernel exposes NURBS and BRep geometry directly to Python and C++ structures, developers can now feed exact geometric boundaries into neural networks or program generative models (like LLMs and Diffusion nets) to create mathematically sound, manufacturable 3D models.
In traditional CAD, BRep is the mathematical standard used to define exact 3D solids by mapping out their boundaries (vertices, edges, and faces). Surfaces are described using NURBS (Non-Uniform Rational B-Splines), allowing for perfectly smooth mathematical curves (like cylinders or organic surfaces) rather than jagged poly meshes.
Backed by Nvidia’s Omniverse platform and its structural framework needed to handle real-world industrial Digital Twins natively there’s possibility for future engineers being able to manipulate heavy industrial CAD assets in a real-time, and potentially even with photorealism.
It is unlikely that Siemens, the developer of the most widely utilised 3D CAD kernel Parasolid will be panicking just yet. With over 30 years of development, troubleshooting and resolving mathematical edge cases, Siemens’ hold on the CAD industry – which runs not only through its own software, but Solidworks, Onshape and many more – will likely remain a key factor in the years to come.
Speaking to DEVELOP3D earlier this year, Siemens Digital Industries CEO Tony Hemmelgram answered our question about the overall design and engineering software landscape, especially with the increasing use of AI – when CAD and AI have previously struggled to work together.
“We’re showing that it can, but look, I would argue there’s already been a lot of free CAD tools and other things out there. There are free kernels that you can use. Is that really what the world needs? No,” he said.
“The value is not in another modeller, the value is in how we can link that LLM to the CAD tools that are there, right? And then the question is, are you open enough to be able to do that? Do you have enough APIs, and so forth. And luckily, we’ve developed NX from the beginning to be able to do that. So, Designcenter has all of these APIs.”
Referencing a project where NX was linked up to Claude, he added, “The value wasn’t in another CAD tool. The value was in how closely we were able to link a very, very good existing CAD tool to an LLM model to be able to drive it and do things with it, right. And so, that’s what we see as being AI driven.”
The SMLib (Solid Modeling Library) geometry kernel forms part of this open source USD BRep project, and was developed originally by Solid Modeling Solutions a software company that specialised in 3D geometry software, and was acquired by Nvidia in May 2022.
SMLib currently powers ClassCAD from AWV Informatik, which has worked with the SMLib team for over 20 years, with its library proving central to ClassCAD’s geometry processing and solid modelling.
Speaking on Linkedin, AWV Informatik CEO Weigel Rainer, said “After more than 20 years of working with SMLib in ClassCAD, it’s exciting to see this geometry kernel become open source and discover what the wider CAD community will build with it.”
It would appear that, in the meantime, while many rush to see what new CAD software can be built with the USD BRep kernel, Nvidia doesn’t seem to be making noises about how it would replace the CAD tools already being used in industry. Instead, it looks more focussed on optimising the pipeline, data translation and downstream framework. However, with a new kernel being not only backed by Nvidia and made open source, what comes of this will be exciting to watch play out.
