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MCAI Classics
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OnlyCSharp 1.7 - render suite

Classical physics and chaos, path traced in pure C#

Twelve small animations - a Lorenz attractor, a double pendulum, a hanging cloth, a fireworks burst, a proof that three colored lights cast three colored shadows. Every pixel comes off one recursive path tracer; every motion is integrated from a real force law or ODE. No game engine, no NuGet, no PNG or texture files - just the BCL and the OnlyCSharp libraries.

See the renders How it is built
12
animations, one renderer
0
NuGet packages referenced
3
RGB lights, 3 real shadows
240×180
native frame, 4:3

Gallery

Each tile is a real simulation, not a loop of keyframes

Four camera views of an object lit by red, green and blue lights, each casting its own colored shadow that overlaps to grey.
Additive colored shadows

Red, green and blue area lights each throw their own shadow; where two shadows overlap the missing light leaves a secondary color, where all three overlap it goes grey. Path-traced soft shadows, 4-camera quad.
A glowing double-lobed ribbon tracing the Lorenz strange attractor.
Lorenz attractor

The classic strange attractor at sigma=10, rho=28, beta=8/3. RK4-integrated, drawn as an emissive ribbon.
A double pendulum swinging chaotically, tracing its bob path.
Double pendulum

Two coupled arms whose motion is famously sensitive to starting angle. Full nonlinear ODE, RK4 stepped.
A pinned cloth sheet sagging and rippling under gravity.
Hanging cloth

A pinned sheet of point masses sags and folds under gravity. Hooke structural, shear and bend springs.
Shells launching and bursting into showers of colored sparks over a dark sky.
Fireworks

Shells rise, burst, and rain down as fading embers. Ballistic particles under gravity and drag.
A hero touring ten themed board squares, shown top-down, from two sides, and third-person.
Themed board squares

A hero walks a serpentine across ten lit dioramas - neon city, forest fireflies, carousel. Every emissive is a real light. Colored path-traced shadows, 4-up.
Dozens of colored arrowheads flocking together and splitting apart.
Boids flocking

Flocks form from nothing but neighbours. Reynolds separation, alignment and cohesion steering.
A bright sun with planets orbiting along a shared plane.
Solar system

Planets sweep out orbits around a central star. Newtonian 1/r-squared gravity.
Two point sources radiating concentric waves that interfere in blue and orange bands.
Two-source interference

Two ripple sources cross into standing bands of reinforcement and cancellation. 2D wave equation on a height field.
Colored parametric curves weaving a rounded box shape.
Lissajous figures

Two perpendicular oscillations at a rational frequency ratio close into a knot. Parametric sine curves, phase swept.
A tongue of procedural flame rising and flickering against black.
Procedural fire

Embers advect upward on a turbulent field and cool through a blackbody color ramp. Simplex-noise particles.

How

One renderer, one rule

Nothing here is drawn with a 2D canvas API. Each frame is rendered by OnlyCSharp.ComputerGraphics.RayTracer.PathTracer - rays are traced, bounced, and accumulated, then denoised, then encoded straight to an animated GIF by the library's own GIF codec. The quad tiles composite four cameras of the same scene: top-down, two sides, and a third-person chase.

The motion is just as literal. Springs pull on the cloth with Hooke's law; the planets feel an inverse-square pull; the double pendulum and the Lorenz system are marched forward with a Runge-Kutta integrator; the boids only ever look at their neighbours. The one rule the whole library keeps is that it depends on nothing outside the .NET base class library - no NuGet, no engine, no image assets - so every result is transliterable and reproducible.