Blitzlichtgewitter

Blitzlichtgewitter is a (slow) ray tracer written in Swift.

It loosely follows the steps described in The Ray Tracer Challenge by Jamis Buck.

Current State

Phong Reflection Model

Ambient Reflection	Diffuse Reflection	Specular Reflection	Result

Usage

The following example renders the "Result" asset from the "Phong Reflection Model" section above:

// 🟢 Creates a unit sphere.
var sphere: Sphere = .unit
// ↗️ Moves the sphere by '1.5' units along the z-axis ("away" from the camera).
sphere.transform = translation(0, 0, 1.5)
// 🎨 Applies some beautiful color ('#88B04B').
sphere.material.color = [ 136.0 / 255.0, 176.0 / 255.0, 75.0 / 255.0 ]

// 💡 Creates a point light source at the upper left corner of the scene.
let light = PointLight(position: point(-10, 10, -10), intensity: [1, 1, 1])

// 📋 Creates a 400x400 (black) canvas to draw the sphere.
var canvas = Canvas(width: 400, height: 400, color: .black)

// 🖌 Draw the sphere on the canvas.
canvas.draw(sphere: sphere, light: light)

// 💾 Writing the '.ppm' image data to disk.
let data = canvas.ppmData()
let url = URL(fileURLWithPath: "/tmp/magic.ppm")
data?.write(to: url)

Roadmap

#	Feature	Status
1	Tuples, Point and Vectors	✅
2	Canvas	✅
3	Matrices	✅
4	Matrix Transformations	✅
5	Ray-Tracing (Ray-Sphere Intersections)	✅
6	Light and Shading (Phong Reflection Model)	✅
7	Scene	-
8	Shadows	-
-	Shoft Shadows (Bonus)	-
9	Planes	-
10	Patterns	-
-	Texture Mapping (Bonus)	-
11	Reflection and Refraction	-
12	Cubes	-
13	Cylinders	-
14	Groups	-
-	Bounding Boxes and Hierarchies	-
15	Triangles	-
16	CSG (Constructive Solid Geometry)	-

API Design & Coding Style

Same as the project itself, the APIs and the coding style will evolve. It's balanced between the Swift API Design Guidelines and the aim staying close to the Cucumber (Gherkin) scenarios described in The Ray Tracer Challenge.