FreeTO

Free plan

What FreeTO is

FreeTO is open-source MATLAB code for building and optimizing free-form 3D topology problems, then examining or exporting the resulting structures. Its main function takes STL files for a design domain and load-carrying subdomains, together with mesh controls and a target volume fraction. You can specify support conditions, force magnitudes, additional load cases, and regions that must remain unchanged during optimization. The code uses a structured hexahedral mesh and produces structures with smooth boundaries. SIMP is the documented default optimization method; SEMDOT is also supported. FreeTO can mirror a topology across as many as three selected symmetry planes. Results include compliance, volume fraction, density arrays, element counts, optimization histories, and a topology display, with an STL file available as an optional output. The repository includes sample problems for a GE bracket, an airplane bracket, a human hand model, and a quadcopter. It carries an MIT license. The available optimizer uses the optimality criteria method; MMA code is commented out, and users are directed to request the relevant code from Prof. Krista Svanberg by email.

Who it suits

FreeTO suits people working with free-form 3D topology optimization who can provide STL geometry and define mesh controls, loads, supports, and a target volume fraction. It may also suit users who want to study or modify open-source MATLAB code under an MIT license.

What it does well

Accepts STL files for the design domain and load-carrying subdomains.
Supports SIMP and SEMDOT optimization methods.
Documents up to nine additional load cases.
Can mirror topology across up to three symmetry planes.
Provides density arrays, optimization histories, and optional STL output.
Includes sample problems for four models.

What to know first

The available optimizer uses optimality criteria; MMA code is commented out.
The README says users must request relevant MMA code by email.
The code relies on other open-source codes, including modified top3D.m.

Limits

The repository version uses the optimality criteria optimizer, while its MMA implementation is commented out. The maker says users must request the relevant code from Prof. Krista Svanberg by email.

Getting started

Open the FreeTO GitHub repository.
Review the README and its sample problems.
Prepare STL files for the design domain and load-carrying subdomains.
Set mesh controls, target volume fraction, supports, forces, and any additional constraints.
Run the main function with SIMP or SEMDOT and review the generated results.

Verdict

Choose FreeTO if you want open-source MATLAB code for setting up and optimizing free-form 3D topology problems, with configurable loads and several documented result types. Look elsewhere if you need the MMA implementation ready to use, since that code is commented out and the maker directs users to request it by email.

Questions

Is FreeTO free?

Yes. FreeTO is listed as free and includes an MIT license.

What optimization methods does it support?

It supports SIMP and SEMDOT, with SIMP as the documented default.

What files does the main function accept?

It accepts STL files for the design domain and load-carrying subdomains, along with mesh controls and a target volume fraction.

What results can FreeTO produce?

Documented results include compliance, volume fraction, density arrays, element counts, optimization histories, and a topology display. An STL file is available as an optional output.

Can I use the MMA optimizer?

The repository's MMA implementation is commented out. The README says users must request the relevant code from Prof. Krista Svanberg by email.

Facts from FreeTO's own pages

Citations: The maker asks users who find the code helpful to cite an open-access paper linked from the repository. · github.com, 4 Oct 2026
Dependencies: The README says FreeTO uses other open-source codes, including intriangulation.m, modified top3D.m, SEMDOT.m, and phi2stl.m. · github.com, 7 Oct 2026
Examples: The repository includes sample problems for a GE bracket, an airplane bracket, a human hand model, and a quadcopter. · github.com, 7 Oct 2026
Founded: 2024 · github.com, 28 Sept 2026
Input: The main function accepts STL files for the design domain and load-carrying subdomains. · github.com, 4 Oct 2026
Input format: The function takes STL files for the design domain and load-carrying subdomains, plus mesh control and a target volume fraction. · github.com, 7 Oct 2026
License: GitHub identifies the repository as open source and links an MIT license. · github.com, 7 Oct 2026
Loads and constraints: Inputs include support conditions, load magnitudes, up to nine additional load cases, and regions that should remain unchanged during optimization. · github.com, 7 Oct 2026
Loads and supports: Inputs can specify support conditions and force magnitudes, and the code documents up to nine additional load cases. · github.com, 4 Oct 2026
Maker: The repository owner profile identifies the maker as Osezua Ibhadode. · github.com, 7 Oct 2026
Mesh and boundaries: It performs 3D topology optimization through structured meshes with smooth boundaries. · github.com, 7 Oct 2026
Optimization methods: The README lists SIMP and SEMDOT as optimization method options, with SIMP as the default. · github.com, 7 Oct 2026
Optimizer limit: The repository version uses the optimality criteria method; the MMA implementation is commented out, and the README says users must request the relevant codes from Prof. Krista Svanberg by email. · github.com, 7 Oct 2026
Optimizer limitation: The repository uses the optimality criteria method; its MMA implementation is commented out, and the maker says users can request the required code from Prof. Krista Svanberg by email. · github.com, 4 Oct 2026
Outputs: Documented outputs include compliance, volume fraction, density arrays, optimization histories, a topology display, and an optional STL file. · github.com, 4 Oct 2026
Purpose: FreeTO is open-source MATLAB code for initializing, optimizing, and post-processing free-form 3D topology optimization problems. · github.com, 7 Oct 2026
Results: Outputs include topology compliance, volume fraction, density arrays, element counts, visual displays, and an optional STL file. · github.com, 7 Oct 2026
Symmetry: The code can mirror an optimized topology across up to three symmetry planes. · github.com, 7 Oct 2026

Where FreeTO stands on Freedom251

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