Godot Shader Development

Godot 4.x shader development guide covering visual effects, materials, particle shaders, and optimization. Use when creating custom shaders, visual effects,...

Security Scan

This is an instruction-only Godot 4.x shader guide (code snippets and explanations) that is internally consistent with its stated purpose and does not request credentials, binaries, or perform installs.

Purpose & Capability

The SKILL.md contains shader explanations and many Godot shader examples matching the name/description. There are no unrelated environment variables, binaries, or install steps requested — what the skill says it does aligns with what it requires.

Instruction Scope

The runtime instructions are purely documentation and shader code (2D/3D/particle/post-processing). They do not reference system files, environment variables, network endpoints, or external services. A few snippets appear truncated or contain logic/typo errors (e.g., expressions like LIFETIME / LIFETIME produce incorrect results, and the file is truncated near the end), which affects usability but not security.

Install Mechanism

No install spec and no code files — lowest-risk model: nothing is written to disk and nothing is downloaded or executed by an installer.

Credentials

The skill requests no environment variables, credentials, or config paths. There are no suspicious 'KEY/TOKEN/PASSWORD' requirements and the examples use only Godot shader globals and uniforms, which is appropriate.

Persistence & Privilege

always is false and there is no installation or persistent agent modification. Autonomous invocation is allowed by platform default but this skill does not request elevated or persistent privileges.

Assessment

This skill is an instruction-only Godot shader guide and appears coherent and low-risk to install. Before using: (1) review and test the snippets in your Godot 4.x project — several examples look incomplete or contain small logic errors (e.g., dividing LIFETIME by itself) that you'll need to fix; (2) verify the truncated section at the end of SKILL.md to ensure you have the full content; (3) prefer skills from a named/trusted author or with a homepage if you need long-term maintenance; and (4) remember that although this skill is safe from a security standpoint (no credentials/installs), you should still validate shader code for performance and correctness in your project.

Godot 着色器开发指南

着色器基础

着色器类型

Spatial (3D):
  - 3D 模型材质
  - 光照和阴影
  - 后处理效果

CanvasItem (2D):
  - 2D 精灵效果
  - UI 特效
  - 粒子系统

Particles:
  - GPU 粒子
  - 高性能粒子效果

基本结构

shader_type canvas_item;

// 顶点着色器（可选）
void vertex() {
    VERTEX += vec2(sin(TIME), cos(TIME));
}

// 片段着色器
void fragment() {
    COLOR = texture(TEXTURE, UV);
}

常用 2D 效果

1. 发光效果

shader_type canvas_item;

uniform float glow_intensity : hint_range(0, 10) = 2.0;
uniform vec4 glow_color : source_color = vec4(1.0, 1.0, 1.0, 1.0);

void fragment() {
    vec4 tex_color = texture(TEXTURE, UV);
    
    // 边缘检测
    vec2 size = TEXTURE_PIXEL_SIZE;
    float alpha = 0.0;
    alpha += texture(TEXTURE, UV + vec2(0.0, -size.y)).a;
    alpha += texture(TEXTURE, UV + vec2(0.0, size.y)).a;
    alpha += texture(TEXTURE, UV + vec2(-size.x, 0.0)).a;
    alpha += texture(TEXTURE, UV + vec2(size.x, 0.0)).a;
    alpha = max(0.0, alpha - tex_color.a * 4.0);
    
    COLOR = tex_color + glow_color * alpha * glow_intensity;
}

2. 波纹扭曲

shader_type canvas_item;

uniform float wave_amplitude = 10.0;
uniform float wave_frequency = 5.0;
uniform float wave_speed = 2.0;

void fragment() {
    vec2 distorted_uv = UV;
    distorted_uv.x += sin(UV.y * wave_frequency + TIME * wave_speed) * wave_amplitude * 0.01;
    distorted_uv.y += cos(UV.x * wave_frequency + TIME * wave_speed) * wave_amplitude * 0.01;
    
    COLOR = texture(TEXTURE, distorted_uv);
}

3. 颜色替换

shader_type canvas_item;

uniform vec4 old_color : source_color = vec4(1.0, 0.0, 0.0, 1.0);
uniform vec4 new_color : source_color = vec4(0.0, 1.0, 0.0, 1.0);
uniform float tolerance : hint_range(0, 1) = 0.1;

void fragment() {
    vec4 tex_color = texture(TEXTURE, UV);
    
    float dist = distance(tex_color.rgb, old_color.rgb);
    if (dist < tolerance) {
        COLOR = vec4(new_color.rgb, tex_color.a);
    } else {
        COLOR = tex_color;
    }
}

4. 溶解效果

shader_type canvas_item;

uniform float dissolve_amount : hint_range(0, 1) = 0.5;
uniform sampler2D noise_texture;
uniform vec4 edge_color : source_color = vec4(1.0, 0.5, 0.0, 1.0);

void fragment() {
    vec4 tex_color = texture(TEXTURE, UV);
    float noise = texture(noise_texture, UV).r;
    
    if (noise < dissolve_amount) {
        discard; // 完全透明
    } else if (noise < dissolve_amount + 0.1) {
        COLOR = edge_color; // 边缘发光
    } else {
        COLOR = tex_color;
    }
}

5. 精灵闪烁

shader_type canvas_item;

uniform float flash_speed = 5.0;
uniform float flash_intensity : hint_range(0, 1) = 0.5;

void fragment() {
    vec4 tex_color = texture(TEXTURE, UV);
    float flash = sin(TIME * flash_speed) * 0.5 + 0.5;
    tex_color.rgb += vec3(flash * flash_intensity);
    COLOR = tex_color;
}

3D 着色器

PBR 材质

shader_type spatial;

uniform vec4 albedo : source_color = vec4(1.0, 1.0, 1.0, 1.0);
uniform float metallic : hint_range(0, 1) = 0.0;
uniform float roughness : hint_range(0, 1) = 0.5;
uniform sampler2D albedo_texture;
uniform sampler2D normal_texture;

void fragment() {
    ALBEDO = albedo.rgb * texture(albedo_texture, UV).rgb;
    METALLIC = metallic;
    ROUGHNESS = roughness;
    NORMAL_MAP = texture(normal_texture, UV).rgb;
}

全息效果

shader_type spatial;

uniform float scanline_speed = 2.0;
uniform float scanline_frequency = 50.0;
uniform vec4 hologram_color : source_color = vec4(0.0, 1.0, 1.0, 1.0);

void fragment() {
    // 扫描线
    float scanline = sin(UV.y * scanline_frequency + TIME * scanline_speed);
    scanline = smoothstep(0.0, 0.5, scanline);
    
    // 边缘发光
    float fresnel = pow(1.0 - dot(NORMAL, VIEW), 3.0);
    
    ALBEDO = hologram_color.rgb;
    ALPHA = (scanline * 0.3 + 0.7) * (fresnel + 0.3);
    EMISSION = hologram_color.rgb * fresnel * 2.0;
}

水面效果

shader_type spatial;

uniform float wave_speed = 1.0;
uniform float wave_height = 0.5;
uniform sampler2D normal_map1;
uniform sampler2D normal_map2;

void vertex() {
    VERTEX.y += sin(VERTEX.x * 2.0 + TIME * wave_speed) * wave_height;
    VERTEX.y += cos(VERTEX.z * 2.0 + TIME * wave_speed * 0.8) * wave_height;
}

void fragment() {
    vec2 uv1 = UV * 1.0 + TIME * 0.05;
    vec2 uv2 = UV * 1.0 - TIME * 0.03;
    
    vec3 n1 = texture(normal_map1, uv1).rgb;
    vec3 n2 = texture(normal_map2, uv2).rgb;
    
    NORMAL_MAP = mix(n1, n2, 0.5);
    ALBEDO = vec3(0.1, 0.4, 0.8);
    METALLIC = 0.8;
    ROUGHNESS = 0.2;
}

粒子着色器

火焰粒子

shader_type particles;

void start() {
    // 初始速度向上
    VELOCITY = vec3(randf_range(-1.0, 1.0), randf_range(2.0, 5.0), randf_range(-1.0, 1.0));
    
    // 随机大小
    float scale = randf_range(0.5, 1.5);
    TRANSFORM[0][0] *= scale;
    TRANSFORM[1][1] *= scale;
    TRANSFORM[2][2] *= scale;
    
    // 随机颜色（红到黄）
    COLOR.r = 1.0;
    COLOR.g = randf_range(0.0, 1.0);
    COLOR.b = 0.0;
}

void process() {
    // 逐渐变小
    float scale = 1.0 - LIFETIME / LIFETIME;
    TRANSFORM[0][0] *= scale;
    TRANSFORM[1][1] *= scale;
    
    // 逐渐透明
    COLOR.a = 1.0 - LIFETIME / LIFETIME;
}

魔法粒子

shader_type particles;

uniform float orbit_radius = 2.0;
uniform float orbit_speed = 2.0;

void start() {
    COLOR = vec4(0.5, 0.0, 1.0, 1.0); // 紫色
    TRANSFORM[3].xyz = vec3(0.0, 0.0, 0.0); // 从中心开始
}

void process() {
    // 环绕运动
    float angle = LIFETIME * orbit_speed;
    TRANSFORM[3].x = cos(angle) * orbit_radius;
    TRANSFORM[3].z = sin(angle) * orbit_radius;
    
    // 闪烁
    COLOR.a = sin(LIFETIME * 10.0) * 0.5 + 0.5;
}

后处理效果

屏幕抖动

shader_type canvas_item;

uniform float shake_intensity = 5.0;
uniform float shake_speed = 10.0;

void fragment() {
    vec2 shake = vec2(
        sin(TIME * shake_speed) * shake_intensity,
        cos(TIME * shake_speed * 1.3) * shake_intensity
    ) * 0.001;
    
    COLOR = texture(TEXTURE, UV + shake);
}

暗角效果

shader_type canvas_item;

uniform float vignette_intensity : hint_range(0, 2) = 0.5;
uniform float vignette_radius : hint_range(0, 1) = 0.8;

void fragment() {
    vec4 tex_color = texture(TEXTURE, UV);
    
    vec2 center = UV - 0.5;
    float dist = length(center);
    float vignette = smoothstep(vignette_radius, 0.0, dist);
    
    tex_color.rgb *= mix(1.0 - vignette_intensity, 1.0, vignette);
    COLOR = tex_color;
}

色差效果

shader_type canvas_item;

uniform float aberration_amount = 0.005;

void fragment() {
    vec2 direction = normalize(UV - 0.5);
    float r = texture(TEXTURE, UV + direction * aberration_amount).r;
    float g = texture(TEXTURE, UV).g;
    float b = texture(TEXTURE, UV - direction * aberration_amount).b;
    
    COLOR = vec4(r, g, b, 1.0);
}

性能优化

技巧

1. 避免复杂计算:
   - 预计算常量
   - 使用 lowp/mediump 精度
   
2. 减少纹理采样:
   - 合并纹理到图集
   - 使用 mipmaps
   
3. 简化条件分支:
   - 使用 mix() 替代 if
   - 避免动态分支
   
4. 利用 GPU 并行:
   - 向量化计算
   - 避免依赖前一个像素

精度选择

// 低精度（移动端）
uniform lowp vec4 color;

// 中精度（大多数情况）
uniform mediump float intensity;

// 高精度（需要精确计算）
uniform highp mat4 transform;

调试技巧

可视化法线

void fragment() {
    ALBEDO = NORMAL * 0.5 + 0.5; // 法线可视化
}

可视化 UV

void fragment() {
    ALBEDO = vec3(UV, 0.0); // UV 可视化
}

性能分析

# 使用 Godot 内置分析器
Debugger > Profiler > Start

# 查看 Draw Calls
Debugger > Monitors > 2D Draw Calls

参考资源

• 常用效果: references/common-effects.md
• 优化指南: references/optimization.md
• 数学函数: references/math-functions.md