TRmesh turns a Rhino solid into a high-quality adaptive tetrahedral mesh, with small elements where the geometry is fine and large ones where it is not. The result is an ordinary Rhino mesh, so it can be saved in a .3dm and viewed in the viewport with no extra software.

How do I install TRmesh or TRfem?

Use Rhino's Package Manager: run the PackageManager command and search for trmesh or trfem. Alternatively download the .yak from cydric.com and run: "C:\Program Files\Rhino 8\System\Yak.exe" install trmesh

Does TRfem require TRmesh?

No. TRfem includes its own tetrahedral meshing components and is a separate product. TRmesh is the better choice when you need high-quality adaptive tet meshes rather than grid-aligned ones.

TRmesh/TRfem for Rhino3D

Q: How do I uninstall TRmesh or TRfem?

Run the PackageManager command in Rhino, find the plug-in under Installed and click Uninstall. Or from a command prompt with Rhino closed: "C:\Program Files\Rhino 8\System\Yak.exe" uninstall trmesh. Your .3dm files are unaffected, because a TRmesh tet mesh is an ordinary Rhino mesh and does not need the plug-in to open.

TRmesh turns a Rhino solid into a high-quality adaptive tetrahedral mesh — the kind finite-element analysis needs, with small elements where the geometry is fine and large ones where it is not.

TRfem solves heat transfer on such a mesh, inside Grasshopper, and brings its own meshing components so it can be used on its own.

The tet mesh is an ordinary Rhino mesh: save it in a .3dm, see it in the viewport, pass it to anything that takes a mesh. No external mesher, no file round-trip, no separate viewer.

USER NEWS — September 2026 · click to expand ↓

The tet mesh is a real Rhino mesh, with user strings. Save it in a .3dm and view it in the viewport like any other mesh.
TRmesh has had a large number of stability fixes, bug fixes and speed-ups on Rhino 8, plus a UI overhaul.
TRmesh remains the best way to generate high-quality adaptive tet meshes.
TRfem is Rhino 9 / Grasshopper 2 only, and does not require TRmesh if grid-aligned tet meshes are good enough for you.
A Mac version of TRmesh is coming, for Rhino 8 too, with the UI for interactive meshing.
The Rhino 9 version of TRmesh will ship a Grasshopper 2 assembly.
Licensing: free during the current beta period.

Got it, thanks.

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

by Mathias Fuchs, last updated September 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).

Download and install

TRfem (heat transfer solver)

Ships as one cross-platform package per Rhino version — the same download works on Windows and Mac.
Rhino 9 (WIP) gets the Grasshopper 2 components; Rhino 8 gets the Grasshopper 1 components.

Your Rhino version:

Recommended: Rhino picks the right build for your version and platform, and tells you when a new one is out. Or download the package directly:

TRmesh (interactive tet mesher)

Standalone Rhino plugin, available for Rhino 8 and Rhino 9. It is a native C++ plugin, so each platform gets its own package — currently Windows only; a Mac version is in progress.
TRfem does not require TRmesh; TRfem includes its own meshing components.

Your Rhino version:

Recommended on Windows. Or download the package directly:

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.

Uninstalling

The simplest way is Rhino’s own package manager: run PackageManager, find the plugin under Installed, and click Uninstall. Restart Rhino and it is gone.

Or from a command prompt, with Rhino closed:

"C:\Program Files\Rhino 8\System\Yak.exe" uninstall trmesh
"C:\Program Files\Rhino 8\System\Yak.exe" uninstall trfem

On macOS, or for Rhino 9, substitute the matching yak — "/Applications/Rhino 8.app/Contents/Resources/bin/yak" or the Rhino 9 WIP path. Uninstalling removes the plugin only; your .3dm files and any meshes saved in them are untouched, because a TRmesh tet mesh is an ordinary Rhino mesh and does not need the plugin to be opened.

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

Subscribe to news about this site by using an RSS feed reader. If you don't have one, you can try popular feed readers like Feedly or NewsBlur. Once you have a feed reader, copy and paste the URL of our RSS feed, https://cydric.com/trmeshrss.xml, into your feed reader to subscribe.

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

Back to cydric.com

Back to mathiasfuchs.com