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EverythingCG

The path

6 levels · 33 lessons

Level 1

Start here

Get a feel for what a pixel, a vector and a colour actually are, before any serious maths.

  1. What a digital image is 30 min
    Every render ends as a grid of numbers, so this is the ground floor.
  2. How colour works on a screen 45 min
    Explains why mixing light is not the same as mixing paint.
  3. Points, vectors and normals 45 min
    Almost every later idea is a vector doing something.
  4. Light and shadow, visually 40 min
    A gentle, interactive picture of how light behaves.
  5. Your first CG program 60 min
    Writes pixels to a file, the smallest working renderer.

Level 2

The maths you need

Build intuition for vectors, matrices and interpolation so the formulas stop feeling like magic.

  1. Essence of linear algebra 3 hours
    Animated intuition for vectors, matrices and transforms.
  2. An intuitive guide to linear algebra 40 min
    A short written companion if you prefer reading.
  3. Moving things with 4x4 matrices 60 min
    This is how every object gets placed, rotated and scaled.
  4. Interpolation 45 min
    Blending between values underlies colour, textures and animation.
  5. Coordinate spaces 45 min
    Local, world, view and clip space explain most 'why is it upside down' bugs.

Level 3

Your first 3D image

See how a camera, a triangle and a ray turn a 3D scene into a flat picture.

  1. The pinhole camera 45 min
    The simplest model of how a 3D point lands on a 2D image.
  2. Perspective projection 45 min
    Shows why far things look small.
  3. Rasterisation overview 60 min
    How real-time graphics fills triangles, fast.
  4. Ray tracing overview 60 min
    The other big way to make an image, by following light backwards.
  5. Ray Tracing in One Weekend 1 weekend
    A hands-on build of a small ray tracer from nothing.
  6. A full intro course on video 10+ hours
    Lectures that tie the whole pipeline together.

Level 4

Light, surfaces and shading

Understand how light bounces off materials so surfaces look matte, shiny or metallic.

  1. What shading is 45 min
    Introduces how light and matter interact.
  2. Phong and BRDFs 60 min
    The classic model, and the idea that leads to physically based materials.
  3. Basic lighting in practice 60 min
    See ambient, diffuse and specular in working code.
  4. Texturing 45 min
    How images wrap onto surfaces to add detail.
  5. Physically based shading theory 90 min
    The modern standard for believable materials.

Level 5

Shaders and real time

Write small GPU programs and learn the tools real-time artists and engineers use.

  1. The Book of Shaders 6 hours
    Learn to paint with maths, one fragment shader at a time.
  2. Inigo Quilez articles Pick and mix
    Short, sharp tricks for signed distance fields, palettes and intersections.
  3. WebGPU fundamentals 3 hours
    The modern browser API for the GPU, explained step by step.
  4. Ray tracing as a coding adventure 1 hour
    Watch a ray tracer get built and debugged in real time.
  5. GPU Gems Pick and mix
    Classic, practical techniques from NVIDIA, free to read online.
  6. Try a real 3D app 2 hours
    Poke a full tool to connect the theory to artist workflows.

Level 6

Go deep

Reach the research edge: path tracing, light transport, neural fields and Gaussian splats.

  1. Monte Carlo methods 90 min
    The random sampling idea behind nearly all modern offline rendering.
  2. Path tracing and global illumination 90 min
    How light bouncing around a scene gets simulated.
  3. Physically Based Rendering, the book Months, dip in
    The reference text on light transport, free online.
  4. Neural radiance fields 2 hours
    Learn a 3D scene from photos with a small neural network.
  5. 3D Gaussian splatting 2 hours
    A fast way to render captured scenes with millions of soft blobs.
  6. Geometry processing Optional deep dive
    Meshes and curvature, the maths under modelling tools.

Everything here is free to read or watch. We link out and never copy. Scratchapixel is free for personal learning; its terms don't allow reuse.

Try it

drag things

Dot product and light direction

Drag the light. Brightness is the dot product of the surface normal and the light direction.

Pairs with: Phong and BRDFs

Ray vs sphere

Drag the orange handle to aim the ray. Solve a quadratic and you know if it hits.

Pairs with: Ray tracing overview

Barycentric triangle fill

Every point in a triangle is a weighted mix of its corners. Those weights blend the colours.

Pairs with: Rasterisation overview

RGB light vs pigment

Pick two colours. Light and paint mix differently.

Pairs with: How colour works on a screen

Easing and curves

Pick a curve. The ball moves with it.

Pairs with: Interpolation