Grid Lines

Use fract() and step() to draw grid lines.

Overview

• Follow the steps to complete the exercise.

Learning Objectives

• Practice coordinate-based coloring

Prerequisites

• uv-coordinates

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);

• Build a hard mask with step.

float mask = step(0.5, uv.x);

• Use floor/fract/mod for tiling and repetition.

vec2 cell = floor(uv * 10.0);
float m = mod(cell.x + cell.y, 2.0);

How To Implement (Step-by-step)

• Start from vUv.
• Build a hard mask with step().
• Use floor/fract/mod for repetition or patterns.
• 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.
• Change frequency by scaling before fract().