case study — 02

Browser-Based Dental CAD

role

Lead 3D Web Engineer

team

Solo — End to End

client

Confidential — Freelance

year

2025

stack

Three.js · Custom Geometry · Node

type

3D Mesh Sculpting & CAD Tool

Contour — browser-based dental CAD interface with sculpt tools and STL workspace
01

Overview

A fully authenticated, browser-based CAD application built from scratch for dental professionals. Users upload 3D STL files of full dental arches — all 32 teeth — manipulate the high-poly geometry directly in the browser, and export the finalized models for 3D printing. The tool bridges the gap between heavy desktop software like Blender and accessible web applications.

02

The Challenge

The core requirement was a professional-grade sculpting toolset with multi-angle orthographic camera views, featuring operations like Close Hole, Smoothing and Sketching. The critical hurdle arose during mesh manipulation: with standard out-of-the-box libraries, the high-poly dental meshes would crack, tear and fail to regenerate under smoothing and hole-closing operations. The complexity of this one feature had already caused the client's previous two development teams to abandon the project.

03

The Solution

Existing NPM packages and standard 3D web libraries simply weren't built for high-fidelity dental mesh manipulation, so I pivoted to engineering the computational geometry myself. I researched and implemented the core algorithms entirely from scratch — Laplacian smoothing for the sculpt-style Smooth operation and Delaunay triangulation for regenerating clean surfaces when closing holes — backed by custom vertex-regeneration logic. The result replicates the fluid, non-destructive sculpting feel of native desktop software, running entirely in a web environment.

  • Laplacian smoothing — iterative vertex relaxation that smooths surfaces without collapsing the fine ridge-and-groove detail of tooth anatomy.
  • Delaunay triangulation — hole boundaries are re-triangulated into well-shaped faces, so patched regions blend seamlessly instead of cracking.
  • Custom vertex regeneration — bespoke logic keeps the mesh watertight and manifold through every edit, a hard requirement for 3D printing.
04

Key Features

Four systems combine into a dependable, professional-grade tool:

  • Custom sculpting algorithms — bespoke Smooth and Close Hole operations that survive high-poly dental meshes without cracking or degradation.
  • Precision 3D raycasting — an interactive sketching tool that lets users draw and map paths directly onto the uneven surface topology of the teeth.
  • Professional CAD interface — a multi-viewport environment with orthographic cameras for precise, multi-angle control over the 3D space.
  • End-to-end pipeline — a secure, authenticated full-stack architecture handling STL parsing, real-time rendering, and a robust STL export optimized for direct-to-3D-printing workflows.
05

The Outcome

The critical smoothing functionality that previous developers could not build shipped, earning high praise from the client. The finalized application is a reliable, standalone tool that empowers dental professionals to upload, modify and export print-ready 3D models entirely via the web.

06

Try It Live

The application is live — log in with the shared test account to explore the full sculpting toolset:

  • Email — test@gmail.com
  • Password — test123
  • OTP — 123456

Launch the live app →

technologies used
Three.jsWebGLReactNode.jsLaplacian SmoothingDelaunay TriangulationSTL Import / Export
32teeth per arch, sculpted in-browser
2dev teams failed before this build
3geometry algorithms written from scratch
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