TRmesh/TRfem for Rhino3D

USER NEWS, click to expand ↓

March 2026: TRfem now requires Rhino WIP (Rhino 9). Grasshopper 2 is only available in Rhino WIP. Install it from rhino3d.com/download/rhino/wip/ (free, works with your Rhino 8 license). A Grasshopper 1 edition may follow later.
TRfem does not require TRmesh. TRfem includes its own tet meshing components. TRmesh is a separate product (Windows only, Rhino 8).
Mesh format: standard Rhino quad mesh where each quad encodes one tetrahedron. Boundary conditions and material indices are stored as mesh data. Conductivities are supplied separately so you can re-solve without re-meshing.
Licensing: free during the current beta period.

Volumetric heat transfer solver and tetrahedral mesher for Rhino / Grasshopper 2

by Mathias Fuchs, last updated March 2026

TRfem solves steady-state heat conduction on tetrahedral meshes. TRmesh generates those meshes interactively inside Rhino. Both are EN ISO 10211 / 10077 compliant. Based on the paper M. Fuchs, Conductive Heat Transfer in Thermal Bridges, Encyclopedia, 2022 (doi:10.3390/encyclopedia2020067).

TRfem (heat transfer solver)

Grasshopper 2 plugin. Requires Rhino WIP (Rhino 9), Windows or Mac.

TRmesh (interactive tet mesher)

Standalone Rhino plugin. Windows only, Rhino 8. TRfem does not require TRmesh; TRfem includes its own meshing components.

What is TRmesh/TRfem?

The usual topology optimization loop

The topology optimization loop with TRmesh

In the past few years, two key factors have driven the need for more complex topology optimization in the digital product development lifecycle:

The 3D printing revolution, granting the designer much more freedom and independence from manufacturing constraints than before
The increased material costs and the need for lighter, cheaper, more sustainable and energy-efficient engineering

At the same time, tetrahedral meshing has failed to shed its dreaded aura and its reputation for being extremely laborious, error-prone and sluggish. One of the reasons for this was that it is not traditionally seen as part of the design and geometry, but is carried out together with the FEA.
TRmesh is here to change that, running tetrahedral meshing where it belongs: as part of the geometry, directly in Rhino3D. This has countless benefits.

TRmesh is a dedicated tetrahedral mesher designed for Rhino3D 7 users on Windows 10 and 11. Built directly on top of the opennurbs C++ API, TRmesh has an advancing-front algorithm that benefits directly from the distance-to-brep APIs of Rhino 7. This ensures a speed directly proportional to the meshing volume versus the volume of the tetrahedra. This results in a predictable and robust meshing process that functions almost linearly with the tetrahedra count.

Unlike traditional mesher, TRmesh is based on a fuzzy philosophy, emphasizing speed.

Features

Rhino panel UI as well Grasshopper components
Remeshing for precise control over mesh density
Robustness: The on-demand version works on Breps, clean and dirty meshes, and even point clouds (!)
Tight integration with TRfem, cydric.com's (academically blessed) heat transfer solver for Rhino3D.

Main benefits of an opennurbs-based tet mesher

Direct Integration: TRmesh operates within your familiar Rhino interface, eliminating the time-consuming process of converting NURBS to custom mesh formats for analysis. Seamless workflow continuity from design to simulation, even with non-manifold geometries typical in multi-material constructs, allowing for an easier transition from conceptual design to structural analysis.
Error Reduction: Traditional topology optimization often requires back-and-forth between design and analysis tools, leading to errors and manual rework. TRmesh maintains the design's integrity through automated mesh generation, ensuring that material properties are accurately represented and reducing the risk of errors in subsequent FEA processes.
Performance Efficiency: Unlike external meshers, TRmesh leverages the power of Rhino's API for rapid distance queries, providing a nearly O(N) performance where N is the expected number of tetrahedra. This technical advantage translates into tangible time savings, enabling faster iterations and more complex analyses without leaving the Rhino environment.

Key Applications

Footwear
Automotive
Naval
Aviation
Prosthetics and orthotics
Additive manufacturing

Usage

Components

Commands beginning with "TRmesh_...", notably "TRmesh_start" to activate the main Rhino user interface panel.
A "TRmesh" menu within Rhino's main menu bar, allowing easy access to the user interface panel.
Grasshopper component category for GH scripting.

Select one or multiple adjacent, non-overlapping input solids for meshing and press the "OK - start" button. Ensure you set the appropriate edge length, with guidance from the displayed recommended target edge length interval. Most tet meshing tasks complete within a 5 to 20-second window.

Post-meshing Options

Modify the target edge length and re-run the tet meshing.
Set a threshold for low-quality tetrahedra peeling and use the "peel" button.
Use the "remesh" button for a fresh meshing session.
Transfer the tetrahedra as Rhino solids into the document (be cautious of file size).
Embed the tetrahedra into user data for continuity across Rhino sessions or reference in the TRfem GH component.
Export the tetmesh to your hard drive in various common tetrahedral meshing formats.

Version and Licensing

This is a free trial version with a variable expiry duration. Its lifespan reduces if used offline. While encompassing most features of the full version, it's not suitable for automated environments outside of Grasshopper. For Rhino3D.compute or Linux server versions, please contact us via email.

The trial license, obtained by downloading TRmesh, is free.

After it expires, a 6 months license including full updates is available. Please drop me an email.

Additional Resources

Food4rhino webinar 1 on TRmesh and TRfem

Food4rhino webinar 2 on TRmesh and TRfem

Latest how-to video (for versions >= 2.99)

Youtube

Forum

Please direct all questions and feedback to discourse.

Examples

See the example site for basic usage examples of TRfem.

RSS Feed

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Terms and Usage Agreement

By using TRmesh, you agree to the Detailed terms and conditions for using TRmesh

Open Source Licenses

mmg is LGPL-licensed. As required, it is dynamically linked into TRmesh. https://github.com/MmgTools/mmg

Contact

For all inquiries or support, please write us an email: mathias@mathiasfuchs.com

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