Taking it into Unity

Everything you've written here is the fragment function of a Unity shader. Unity wraps it with a bit of boilerplate. Hit “Copy for Unity” above the editor to get a complete ShaderLab file for any exercise.

Try it (5 minutes)

1. In Unity: Assets → Create → Shader → Unlit Shader, open it, replace everything with the exported text.
2. Create → Material, pick your shader, drag the material onto a Quad (or a Sphere!).

What the boilerplate does

• Vertex shader (vert): runs once per vertex of the mesh and places it on screen. A Quad has 4 vertices. The GPU then fills in the pixels between them.
• Per-vertex values like the UV are interpolated across the triangle and arrive in the fragment shader: that's where uv comes from. On this page the “mesh” is just one rectangle covering the screen.
• Fragment shader (frag): runs once per pixel — what you've been writing.

Differences to know

This page	In Unity
time	_Time.y (works on this page too)
aspect	_ScreenParams.x / _ScreenParams.y (also works on this page), or 1 on a square Quad
uv on a screen-filling rectangle	uv from the mesh (0..1 over a Quad; whatever the artist unwrapped on other models)
solid colors only	add Properties { _Color("Color", Color) = (1,1,1,1) } to expose sliders/colors; sampler2D _MainTex + tex2D(_MainTex, uv) for textures

The 3D raymarch lessons work on a Quad too, but in Unity you'd often shade real meshes instead: your fragment function would get world normals and light directions from the vertex stage. The next step on your own: learn Shader Graph or surface shaders to get Unity's lighting for free — the math you've practiced is the same.

Below is a free playground. Hit Reset for the starter; no target, just experiment!