csRaymarching (Terminal Raymarcher)

A real-time CPU raymarcher that renders signed-distance-field scenes directly inside a terminal using ANSI / VT escape sequences and Unicode block characters.

It is intentionally "overkill ASCII art": multi-core raymarching, shading, and a smooth free-fly camera, all presented as chunky terminal pixels.

Features

• CPU raymarching using signed distance fields (SDF)
• Parallel rendering using Parallel.For (scales well with core count)
• Half-block rendering mode for effectively double vertical resolution
• Basic shading using surface normals and optional fog
• Dirty-row terminal flushing for fast and stable redraws
• Smooth camera controls with adjustable movement speed

Controls

• W / A / S / D - Move (x)
• E / Q - Move up / down (z)
• Arrow keys - Look (yaw / pitch)
• Left Shift - Sprint
• 1 / 2 / 3 / 4 - Set movement speed
• Space - Pause
• H - Toggle half-block rendering
• F - Toggle fog
• G - Toggle gamma colorization
• C - Cycle color theme
• R - Reset scene
• I - Toggle debug / info overlay
• F1 / F2 / F3 / F4 - Target FPS (30 / 60 [Default] / 120 / 144)
• Esc - Quit
• Num 0 - 5 - Scenes

Requirements

• .NET 10
• A terminal that supports ANSI / VT escape sequences and Unicode block glyphs

Recommended terminal:

• Windows Terminal on Windows 11 (very stable under heavy redraw)

This project is intentionally CPU-heavy. Performance depends strongly on core count, cache size, and sustained clock speed. Larger window will be harder to run smoothly. @ 1920x1080 terminal size, I get about 30-40 FPS with a R9 9900X3D.

Project Layout (High Level)

• Program.cs
  Main loop, frame pacing, input polling, resize handling, UI overlay

• RaymarchRenderer.cs
  Core raymarch and shading pipeline (parallel rendering, half / full block modes)

• Scene.cs / DistanceFields.cs
  Signed distance field scene description and distance functions

• Camera3D.cs / Ray.cs
  Free-fly camera model and ray generation

• Shading.cs
  Color, lighting, fog, and background shading

• ConsoleCanvas.cs / WindowsConsole.cs / ConsoleInteraction.cs
  Fast terminal output, VT handling, and buffered rendering

• Settings.cs / Theme.cs
  Runtime settings and visual themes

Tweaking

Most tuning parameters live in Settings.cs (initialized in Program.cs), including:

• MaxRaymarchSteps
• MaxRenderDistance
• FieldOfView
• MoveSpeed
• EnableFog / FogDensity
• UseHalfBlocks
• TargetFps
• MapColorsWithGamma

License

MIT License — see LICENSE file.

(c) 2026 NiTROZ