Shader to animate Line2D

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, ,
1

Godot Version

v4.6

Question

Hi,

I’m trying to do a casual game where there are some cells which border is a line2D.

I would like to animate this line with a shader to achieve something near to following example:

0_mYax_TCyzGg_dpnL

But I cannot imagine how to achieve this effect.

Someone has any idea to program a shader with this behaviour?

Thanks!

2

Ok, solved.

shader_type canvas_item;

uniform vec4 line_color : source_color = vec4(0.0, 0.6, 1.0, 1.0);
uniform float speed : hint_range(0.0, 10.0) = 2.0;
uniform float tail_length : hint_range(0.0, 1.0) = 0.3; // Largo de la estela
uniform float glow_intensity : hint_range(1.0, 5.0) = 2.0;

void fragment() {

    float time_cycle = fract(TIME * speed * 0.1);
    float dist = fract(UV.x - time_cycle);
    float mask = smoothstep(1.0 - tail_length, 1.0, dist);
    vec4 final_color = line_color * mask * glow_intensity;
    COLOR = vec4(final_color.rgb, mask * line_color.a);
}