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