A small ray tracer in C# / .NET 10 / Windows Forms, turned into a real-time, interactive viewer: orbit the scene with the mouse, zoom, pan, and watch the little sphere bounce continuously.
It all started from the brilliant LINQ-raytracer by Luke Hoban, a ray tracer written as a single LINQ query. That demo blew my mind for years: seeing an entire 3D scene emerge from a from … where … select is one of those things that durably changes how you look at a language.
A huge thank you to Luke Hoban. His code has been an enduring source of inspiration to me, a reminder of what sheer expressive elegance can produce.
The original tracer renders a single still image in a few seconds. The goal here was the opposite: interact with the scene while it renders. It was all done with Claude Code in "doodle" mode, small, fast iterations, sketching ideas out loud, trying things, tweaking, with the agent bridging idea and code.
The main building blocks:
- Interactive orbit camera - left-click-drag to rotate around the scene, wheel to zoom.
- Camera pan - right-click-drag to slide the point of interest.
- Render pipeline scheduling - at most 1 render in flight + 1 pending, and atomic framebuffer flush (no more bands while moving).
- Geometry on
System.Numerics.Vector3- SIMD throughout the geometry pipeline. - Continuous animation - the small sphere bounces in a loop, independently of user input.
dotnet run -c ReleaseRequirements: .NET 10 SDK, Windows (the project uses Windows Forms for the window and System.Drawing for the framebuffer).
| Action | Gesture |
|---|---|
| Orbit camera | left-click + drag |
| Pan camera | right-click + drag |
| Zoom | mouse wheel |
- Original code: Luke Hoban - LINQ-raytracer
- Real-time makeover: doodled with Claude Code