Fresnel

Learn core lighting terms (diffuse/specular/rim) on a simple sphere.

Overview

• Follow the steps to complete the exercise.

Learning Objectives

• Understand the math behind the lighting term

Prerequisites

• lambert-sphere

Key Concepts

• vUv is normalized UV in [0,1].

vec2 uv = vUv;

• Blend values with mix(a, b, t).

vec3 color = mix(colorA, colorB, t);

• Distance fields with length/distance.

float d = length(uv - 0.5);

How To Implement (Step-by-step)

• Start from vUv.
• Compute a distance value for masks/shapes.
• Use mix() to blend outputs.

Self-check

• Does it compile without errors?
• Does the output match the goal?
• Are key values kept in [0,1]?

Common Mistakes

• Clamp t into [0,1] when needed.