shader-patterns

Shader Patterns

Dissolve Effect (Godot Spatial)

shader_type spatial;
render_mode blend_mix, depth_draw_opaque, cull_back;

uniform sampler2D albedo_texture : source_color;
uniform sampler2D noise_texture;
uniform float dissolve_amount : hint_range(0.0, 1.0) = 0.0;
uniform vec4 edge_color : source_color = vec4(1.0, 0.4, 0.0, 1.0);
uniform float edge_width : hint_range(0.0, 0.2) = 0.05;

void fragment() {
    vec4 albedo = texture(albedo_texture, UV);
    float noise = texture(noise_texture, UV).r;

    // Discard fragments below dissolve threshold
    if (noise < dissolve_amount) {
        discard;
    }

    // Glow at dissolve edge
    float edge = smoothstep(dissolve_amount, dissolve_amount + edge_width, noise);
    vec3 emission = mix(edge_color.rgb, vec3(0.0), edge);

    ALBEDO = albedo.rgb;
    EMISSION = emission;
    ALPHA = albedo.a;
}

Outline Shader (Godot CanvasItem / 2D)

shader_type canvas_item;

uniform vec4 outline_color : source_color = vec4(0.0, 0.0, 0.0, 1.0);
uniform float outline_width : hint_range(0.0, 10.0) = 2.0;

void fragment() {
    vec2 uv = UV;
    vec2 texel_size = outline_width / vec2(textureSize(TEXTURE, 0));

    float alpha = texture(TEXTURE, uv).a;

    // Sample 8 neighbors
    float neighbor_alpha = 0.0;
    neighbor_alpha += texture(TEXTURE, uv + vec2(texel_size.x, 0.0)).a;
    neighbor_alpha += texture(TEXTURE, uv + vec2(-texel_size.x, 0.0)).a;
    neighbor_alpha += texture(TEXTURE, uv + vec2(0.0, texel_size.y)).a;
    neighbor_alpha += texture(TEXTURE, uv + vec2(0.0, -texel_size.y)).a;
    neighbor_alpha += texture(TEXTURE, uv + vec2(texel_size.x, texel_size.y)).a;
    neighbor_alpha += texture(TEXTURE, uv + vec2(-texel_size.x, texel_size.y)).a;
    neighbor_alpha += texture(TEXTURE, uv + vec2(texel_size.x, -texel_size.y)).a;
    neighbor_alpha += texture(TEXTURE, uv + vec2(-texel_size.x, -texel_size.y)).a;

    // If any neighbor has alpha but this pixel doesn't: draw outline
    if (alpha < 0.1 && neighbor_alpha > 0.1) {
        COLOR = outline_color;
    } else {
        COLOR = texture(TEXTURE, uv);
    }
}