Melt 3D — make things together

A free, beginner-friendly 3D modeller that turns a school's 3D printer into a shared classroom space: students design soft, clay-like objects, teach each other, and share print-ready models.

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The problem

School 3D printers often sit unused. Beginner tools feel like toys, professional CAD is too hard for a first lesson, and students end up working alone, if at all.

What Melt 3D does

Melt 3D is a free, open-source desktop 3D modeller where shapes melt into each other like clay. Students drop in simple shapes, blend them into soft organic forms, and still type exact millimetre dimensions. It supports sketch → extrude, curves and pipes, colour and gloss, and print-checked export to STL / 3MF / OBJ / PLY / GLB. It has a guided beginner flow and a Japanese/English UI, and runs on ordinary school laptops.

How it helps people connect

  • The school printer becomes a shared classroom space: one tool everyone can use in their first 10 minutes
  • Peer teaching: students who learn it first can teach classmates, using the bilingual beginner guide
  • Open-source sharing: print-ready models and the code are public on GitHub so students can share and remix

Built during the Sparkathon

  • Shell tool
  • Twist presets (work in progress)
  • Beginner guide
  • Responsiveness improvements
  • SolidCraft v0.26.0 upgrade
  • Shape-cache fix More work will be added in November before the final deadline.

Pre-existing work (disclosure)

The project started on 15 Oct 2026. It is built on the open-source SolidCraft CAD kernel (https://github.com/tangency-labs/solidcraft, MIT OR Apache-2.0). The core melt modelling, UI and export were done before 29 Oct 2026. My own work is mainly in apps/meltcad/. Not affiliated with the SolidCraft authors.

Built with

Rust, egui, wgpu, SDF smooth-union/subtract, SolidCraft.

AI disclosure

I used AI coding assistants (ChatGPT / Claude / Cursor) for code suggestions, debugging help, and drafting documentation/translations. All design decisions, architecture, integration, testing, and final review are mine. Melt 3D itself has no AI feature yet.

Team

Solo: Taichiro Eguchi (07egta), 16, Japan.

Links: https://github.com/07egta/melt3D · https://github.com/07egta/melt3D/releases/latest · https://www.youtube.com/watch?v=MzCUpGwC2xI

Built With

  • 3mf
  • egui
  • rust
  • solidcraft
  • stl
  • wgpu
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