The studio image, clearcoat, and a wrong file name
The first load asks for a file that does not exist and prints the 404. Then the real image loads. Left to right: rough paint, glossy paint, car paint (clearcoat), brushed metal. There are no lights: the environment is the only light.
Physically based rendering describes a surface with two numbers, metalness and roughness, and lights it with rules from real optics. You learn what each number does, why metal needs something to reflect, and what clearcoat adds for car-style paint.
Change the code and press Run (Ctrl+Enter). Predict what will happen first, then break it on purpose and read what changes. Your edits are saved and match the lesson page.
Ready for more? This phase has 5 hands-on exercises with automatic checks.
Practice questions
Write the code in the editor, run it, then open the model answer to compare.
Build a chrome bell: a sphere that looks like polished metal using the course's studio image. Write the setup.
Make the paint ball look like car paint with a lacquer that is sharper than the paint under it.
Explain it without notes
Why is a metal ball black under an AmbientLight, and what are two ways to fix it?
What do metalness and roughness each control, and why does roughness not make a surface darker overall?
Console
Nothing logged yet.Expected console output
wrong path: fetch for "/data/3d/hdr/missing.hdr" responded with 404: Not Found
HDR image: 1024 x 512 pixels, type half float
environment set: true