Step Function Mask

Learning Objectives

Learn to use the step() function to create a sharp left-right division on screen. This is a basic technique for masking, logic control, and crisp UI effects.

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Key Concepts

1. step(edge, x)

This function outputs:

`glsl

float result = step(edge, x);

`

- Returns 0.0 when x < edge

- Returns 1.0 when x >= edge

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2. Creating a vertical split

We use vUv.x to get horizontal position:

`glsl

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

`

Fragments on the left will return 0, right side returns 1.

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3. Color blending using mask

`glsl

vec3 color = mix(leftColor, rightColor, mask);

`

This creates a hard edge color division in the middle of the screen.