Making a 3D Modeler, in C, in a Week
Last fall I participated in a week long programming event called the Wheel Reinvention Jam. The point of the Jam was to revisit existing software systems with fresh eyes. I ended up making a 3D modeler called “ShapeUp”. This post will make more sense if you watch the video demo of ShapeUp before reading more. You can try ShapeUp in your browser.
I hate how slow the typescript compiler is (this connects, trust me). The jam seemed like a good opportunity to implement a faster subset of Typescript to beat tsc. Starting with the esbuild or Bun typescript parser made the project seem plausible. It dawned on me that success would look like one terminal command finishing faster than another. As far as demos go, not super compelling. I wanted a cool demo. So I pivoted to 3D.
The only reason a 3D project from scratch in a week seemed doable was because of a technique called ray marched signed distance fields (SDFs). A ray marched SDF scene with colors, soft shadows, and ambient occlusion can be implemented much faster than an equivalent triangle based renderer. The amazing Inigo Quilez uses SDFs to create pixar-like characters in one sitting. I had written SDF shaders before but they were rudimentary. Modeling by editing code felt unnatural to me. I wanted to edit the shapes with a mouse. This jam seemed like my chance to make that a reality. I named it ShapeUp.
.jpg)
