Ten renders, zero dependencies

Pictures a C# library drew by itself

Each of these ten programs computes something real - Perlin terrain, the analemma, the Lorenz attractor, a path-traced scene - then writes it to a PNG or GIF with OnlyCSharp 1.8's own image codec. No SkiaSharp, no ImageSharp, no GPU: every pixel is placed by Image.SetPixel and every glyph by a hand-rolled 5x7 bitmap font.

See the renders

Procedural terrain

A six-octave Perlin + fBm height field, tinted by elevation and lit with analytic hillshading.

ComputerGraphics.Noise

Northern star chart

The named-star catalogue placed by true RA/Dec, sized by magnitude, tinted by B-V colour, with real constellation figures.

PhysicsAndAstronomy.Astronomy

The analemma

The Sun at local noon on every day of a year traces a figure-8 - 366 real solar-position calls for Seattle.

PhysicsAndAstronomy.Astronomy

Lunar phase calendar

Thirty consecutive nights, each Moon drawn exactly as it appears - illuminated fraction and true terminator ellipse.

PhysicsAndAstronomy.Astronomy

Lorenz attractor

The canonical strange attractor, integrated by the library's RK4 Lorenz solver (sigma=10, rho=28, beta=8/3) over 16,000 steps.

PhysicsAndAstronomy.Physics.ChaosDynamics

Voronoi mosaic

Ninety seed points partition the plane into cells via a real Delaunay/Voronoi build; each cell is filled and outlined.

Mathematics.Geometry.Delaunay

Path-traced spheres

Three matte spheres lit by an emissive panel, rendered by the real path tracer with global illumination - 160 spp, HDR to tonemap.

ComputerGraphics.RayTracer

08 Animated

Rigid-body cascade

Twenty-four spheres dropped into a walled pit - falling, colliding, settling in a real 3-D world - encoded to GIF.

PhysicsAndAstronomy.Physics.Physics3D

RNG uniformity

OcPcg32 shown two ways: 9,000 2-D points filling the square with no clumping, and 400,000 draws binned flat.

Mathematics.Fast.Rng

Domain-warped flow

An fBm field whose coordinates are displaced by a second fBm field - a swirling marble/nebula texture in an ember palette with iso-contours.

ComputerGraphics.Noise

How every pixel got there

There is no drawing library underneath any of these. The astronomy (real RA/Dec, solar and lunar positions), the noise, the chaos integrator, the Delaunay build and the path tracer are all genuine library compute. The output is written straight into an in-memory Image a pixel at a time, then serialized by OnlyCSharp's own PNG and Gif89a encoders. Text is stamped from a hand-rolled 5x7 bitmap font.

Because the seeds and dates are fixed, every image is byte-reproducible: run the console app twice and you get the identical file. The slowest frame is the path-traced scene at roughly 4.9 seconds; the analemma renders in about 22 milliseconds.