The Tech Behind Geotoy

A deep technical breakdown of Geotoy, a Shadertoy-inspired web app for building 3D meshes with a custom DSL called Geoscript. The stack spans a custom Rust half-edge-like mesh data structure (LinkedMesh), robust CSG via the manifold library (solving long-standing manifold mesh boolean problems), Three.JS rendering with custom GLSL shaders and triplanar mapping, WebAssembly compilation of Rust and C++ code via wasm-bindgen and Emscripten, a Pest-based parser for the Geoscript DSL, UV unwrapping via boundary-first-flattening compiled to Wasm, SvelteKit for the frontend, and a Puppeteer-based thumbnail generator microservice. The author also covers const-eval optimizations, Lezer-based syntax highlighting in CodeMirror, and a simple Docker-based self-hosted deployment setup.