3D Text Bouncer

A Windows desktop application that renders text as a physically-simulated 3D particle cloud bouncing inside a translucent polyhedron. Built in C# with WPF, OpenTK, HelixToolkit.Wpf, and .NET 8.

Features

• Text-to-Particles — Convert any text into a 3D particle cloud using SkiaSharp rasterization with scanline even-odd hole detection (letters like O, P, Q, 0, 9 remain hollow)
• Physics Simulation — Fixed-timestep elastic collision with letter boundary constraints, keeping particles inside text shapes
• Polyhedron Container — Choose from multiple polyhedra (cube, tetrahedron, octahedron, dodecahedron, icosahedron, etc.) as the bouncing container
• Transparency Modes — Render face-only, whole polyhedron, or wireframe-only with adjustable opacity
• 18 Fill Rules — Configurable polygon triangulation and 3D rendering strategies:
  • 2D Triangulation: Fan from Centroid, Ear Clipping, Convex Hull, Strip Partition, Kirkpatrick, Monotone Partition, and more
  • 3D Rendering: Painter Back-to-Front, Backface Culling, Normal Angle Shading, Distance Fog, Emissive Glow, Spectral Coloring
• Control Modes
  • Automatic — Physics drives particle motion
  • Manual — Override box position and rotation via sliders
  • Mixture — User input applies forces to physics
• Live Parameter Adjustment — Particle count (1K–100K), text color, box opacity, polyhedron selection
• Additive Slider System — Position/rotation sliders accumulate deltas rather than setting absolute values, allowing continuous adjustment

Screenshots

Screenshots coming soon

Getting Started

Prerequisites

• Windows 10 or later
• .NET 8 SDK

Build & Run

dotnet build src
dotnet run --project src

Run Tests

dotnet test

Architecture

src/
├── FillRules/
│   ├── AlternatingFanStrategy.cs      # Alternating fan triangulation
│   ├── AlternatingOpacityRule.cs      # Alternating face opacity (3D)
│   ├── BackfaceCullingRule.cs         # Cull back-facing faces (3D)
│   ├── ConvexHullStrategy.cs          # Convex hull triangulation
│   ├── DialStrategy.cs                # Minimum diagonal angle
│   ├── DistanceFogRule.cs             # Depth-based fog (3D)
│   ├── EarClipTriangulationStrategy.cs # Ear clipping triangulation
│   ├── EmissiveGlowRule.cs            # Emissive glow effect (3D)
│   ├── FanFromVertexStrategy.cs       # Fan from first vertex
│   ├── FanTriangulationStrategy.cs    # Fan from face centroid
│   ├── FillRuleConfig.cs              # Strategy registry and presets
│   ├── HertelMehlhornStrategy.cs      # Hertel-Mehlhorn approximation
│   ├── IFillRuleStrategy.cs           # Strategy interface
│   ├── KirkpatrickStrategy.cs         # Kirkpatrick triangulation
│   ├── MinimumDiagonalStrategy.cs     # Minimum diagonal selection
│   ├── MonotonePartitionStrategy.cs   # Monotone partition
│   ├── NeighborFanStrategy.cs         # Fan from neighboring faces
│   ├── NormalAngleShadingRule.cs      # Normal-based shading (3D)
│   ├── PainterBackToFrontRule.cs      # Painter's algorithm (3D)
│   ├── SpectralColoringRule.cs        # Spectral coloring (3D)
│   └── WireframeOverlayRule.cs       # Wireframe overlay (3D)
├── PolyhedronData.cs           # Polyhedron vertices, edges, faces
├── ParticleData.cs             # Particle struct (position, velocity, color, 48 bytes)
├── ParticleGenerator.cs        # Bitmap sampling with scanline even-odd hole detection
├── PhysicsSimulator.cs        # Fixed-timestep elastic collision physics
├── TextRasterizer.cs          # SkiaSharp text-to-bitmap rasterization
├── MainWindow.xaml.cs         # WPF 3D viewport, rendering loop, UI event handlers
└── ControlMode.cs             # Automatic / Manual / Mixture modes

Tech Stack

Component	Technology
Runtime	.NET 8 LTS
3D Rendering	HelixToolkit.Wpf 2.24.0 (WPF 3D viewport)
Math / Particles	OpenTK.Mathematics 4.9.4
UI Framework	WPF
Text Rasterization	SkiaSharp 3.119.2
Physics	Custom fixed-timestep accumulator pattern

Roadmap

Phase	Status	Description
1. Foundation	✅	WPF HelixToolkit viewport, basic 3D rendering pipeline
2. Text-to-Particles	✅	SkiaSharp rasterization, scanline hole detection, particle distribution
3. Particle Rendering	✅	Point cloud rendering via HelixToolkit, 100K particles
4. Physics Simulation	✅	Fixed-timestep elastic collision, letter boundary constraints
5. UI Integration	✅	Camera controls, side panel, sliders, polyhedron selection, fill rules
6. Mixture Mode & Polish	⏳	Hybrid physics/manual interaction, polish

License

MIT License - feel free to modify and extend!