Moving Gradient

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📝 Exercise Goal

Animate a gradient by shifting vUv.x over time.

💡 💡 Tutorial Content

Animate a gradient by shifting vUv.x over time.

Overview

  • Implement a horizontal gradient using UV as the factor.

Learning Objectives

  • Use fract() for looping motion
  • Animate UV-based factor

Prerequisites

  • horizontal-gradient

Inputs

  • float u_time — Time in seconds.

Key Concepts

  • A horizontal gradient uses a 0-1 factor (usually UV) to blend colors.
float t = vUv.x;
vec3 color = vec3(t);
  • Keep the factor inside [0,1].
t = clamp(t, 0.0, 1.0);

How To Implement (Step-by-step)

  • Set factor: t = vUv.x.
  • Map t to a color (grayscale or mix).
  • Output gl_FragColor with alpha=1.

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().

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