Shader Techniques Shader Pipeline Overview ┌─────────────────────────────────────────────────────────────┐ │ RENDERING PIPELINE │ ├─────────────────────────────────────────────────────────────┤ │ CPU (Game Logic) │ │ ↓ │ │ VERTEX SHADER │ │ ├─ Transform vertices to clip space │ │ ├─ Calculate normals, tangents │ │ └─ Pass data to fragment shader │ │ ↓ │ │ RASTERIZATION (Fixed function) │ │ ├─ Triangle setup │ │ ├─ Pixel coverage │ │ └─ Interpolation │ │ ↓ │ │ FRAGMENT/PIXEL SHADER │ │ ├─ Sample textures │ │ ├─ Calculate lighting │ │ └─ Output final color │ │ ↓ │ │ OUTPUT (Framebuffer) │ └─────────────────────────────────────────────────────────────┘
Basic Shader Structure // ✅ Production-Ready: Basic Surface Shader (Unity HLSL) Shader "Custom/BasicSurface" { Properties { _MainTex ("Albedo", 2D) = "white" {} _Color ("Color Tint", Color) = (1,1,1,1) _Metallic ("Metallic", Range(0,1)) = 0.0 _Smoothness ("Smoothness", Range(0,1)) = 0.5 _NormalMap ("Normal Map", 2D) = "bump" {} _NormalStrength ("Normal Strength", Range(0,2)) = 1.0 }
SubShader
{
Tags { "RenderType"="Opaque" "Queue"="Geometry" }
LOD 200
CGPROGRAM
#pragma surface surf Standard fullforwardshadows
#pragma target 3.0
sampler2D _MainTex;
sampler2D _NormalMap;
half4 _Color;
half _Metallic;
half _Smoothness;
half _NormalStrength;
struct Input
{
float2 uv_MainTex;
float2 uv_NormalMap;
};
void surf(Input IN, inout SurfaceOutputStandard o)
{
// Albedo
half4 c = tex2D(_MainTex, IN.uv_MainTex) * _Color;
o.Albedo = c.rgb;
// Normal mapping
half3 normal = UnpackNormal(tex2D(_NormalMap, IN.uv_NormalMap));
normal.xy *= _NormalStrength;
o.Normal = normalize(normal);
// PBR properties
o.Metallic = _Metallic;
o.Smoothness = _Smoothness;
o.Alpha = c.a;
}
ENDCG
}
FallBack "Diffuse"
}
Advanced Effects Toon/Cel Shading // ✅ Production-Ready: Toon Shader Shader "Custom/Toon" { Properties { _MainTex ("Texture", 2D) = "white" {} _Color ("Color", Color) = (1,1,1,1) _RampTex ("Ramp Texture", 2D) = "white" {} _OutlineColor ("Outline Color", Color) = (0,0,0,1) _OutlineWidth ("Outline Width", Range(0, 0.1)) = 0.02 }
SubShader
{
Tags { "RenderType"="Opaque" }
// Outline Pass
Pass
{
Cull Front
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
struct appdata
{
float4 vertex : POSITION;
float3 normal : NORMAL;
};
struct v2f
{
float4 pos : SV_POSITION;
};
float _OutlineWidth;
float4 _OutlineColor;
v2f vert(appdata v)
{
v2f o;
// Expand vertices along normals
float3 scaled = v.vertex.xyz + v.normal * _OutlineWidth;
o.pos = UnityObjectToClipPos(float4(scaled, 1.0));
return o;
}
half4 frag(v2f i) : SV_Target
{
return _OutlineColor;
}
ENDCG
}
// Main Toon Pass
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
sampler2D _MainTex;
sampler2D _RampTex;
float4 _Color;
struct appdata
{
float4 vertex : POSITION;
float3 normal : NORMAL;
float2 uv : TEXCOORD0;
};
struct v2f
{
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
float3 worldNormal : TEXCOORD1;
};
v2f vert(appdata v)
{
v2f o;
o.pos = UnityObjectToClipPos(v.vertex);
o.uv = v.uv;
o.worldNormal = UnityObjectToWorldNormal(v.normal);
return o;
}
half4 frag(v2f i) : SV_Target
{
// Sample albedo
half4 col = tex2D(_MainTex, i.uv) * _Color;
// Calculate diffuse with ramp
float3 lightDir = normalize(_WorldSpaceLightPos0.xyz);
float NdotL = dot(i.worldNormal, lightDir) * 0.5 + 0.5;
float3 ramp = tex2D(_RampTex, float2(NdotL, 0.5)).rgb;
col.rgb *= ramp;
return col;
}
ENDCG
}
}
}
Dissolve Effect // ✅ Production-Ready: Dissolve Shader Shader "Custom/Dissolve" { Properties { _MainTex ("Texture", 2D) = "white" {} _NoiseTex ("Noise Texture", 2D) = "white" {} _DissolveAmount ("Dissolve Amount", Range(0, 1)) = 0 _EdgeColor ("Edge Color", Color) = (1, 0.5, 0, 1) _EdgeWidth ("Edge Width", Range(0, 0.2)) = 0.05 }
SubShader
{
Tags { "RenderType"="Opaque" }
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
sampler2D _MainTex;
sampler2D _NoiseTex;
float _DissolveAmount;
float4 _EdgeColor;
float _EdgeWidth;
struct v2f
{
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
};
v2f vert(appdata_base v)
{
v2f o;
o.pos = UnityObjectToClipPos(v.vertex);
o.uv = v.texcoord;
return o;
}
half4 frag(v2f i) : SV_Target
{
half4 col = tex2D(_MainTex, i.uv);
float noise = tex2D(_NoiseTex, i.uv).r;
// Discard dissolved pixels
clip(noise - _DissolveAmount);
// Add edge glow
float edge = 1 - smoothstep(0, _EdgeWidth, noise - _DissolveAmount);
col.rgb = lerp(col.rgb, _EdgeColor.rgb, edge);
return col;
}
ENDCG
}
}
}
Post-Processing Effects // ✅ Production-Ready: Screen-Space Vignette Shader "PostProcess/Vignette" { Properties { _MainTex ("Texture", 2D) = "white" {} _Intensity ("Intensity", Range(0, 1)) = 0.5 _Smoothness ("Smoothness", Range(0.01, 1)) = 0.5 }
SubShader
{
Pass
{
CGPROGRAM
#pragma vertex vert_img
#pragma fragment frag
sampler2D _MainTex;
float _Intensity;
float _Smoothness;
half4 frag(v2f_img i) : SV_Target
{
half4 col = tex2D(_MainTex, i.uv);
// Calculate vignette
float2 center = i.uv - 0.5;
float dist = length(center);
float vignette = smoothstep(0.5, 0.5 - _Smoothness, dist);
vignette = lerp(1, vignette, _Intensity);
col.rgb *= vignette;
return col;
}
ENDCG
}
}
}
Shader Optimization OPTIMIZATION TECHNIQUES: ┌─────────────────────────────────────────────────────────────┐ │ PRECISION: │ │ • Use half instead of float where possible │ │ • Mobile: Always prefer half/fixed │ │ • PC: float for positions, half for colors │ ├─────────────────────────────────────────────────────────────┤ │ TEXTURE SAMPLING: │ │ • Minimize texture samples │ │ • Use texture atlases │ │ • Avoid dependent texture reads │ │ • Use lower mipmap for distant objects │ ├─────────────────────────────────────────────────────────────┤ │ MATH OPERATIONS: │ │ • Replace div with mul (x/2 → x0.5) │ │ • Use MAD operations (ab+c) │ │ • Avoid branching in fragment shaders │ │ • Pre-compute constants │ ├─────────────────────────────────────────────────────────────┤ │ VARIANTS: │ │ • Minimize shader keywords │ │ • Use multi_compile_local │ │ • Strip unused variants │ └─────────────────────────────────────────────────────────────┘
COST COMPARISON (Relative): ┌─────────────────────────────────────────────────────────────┐ │ Operation │ Cost │ Notes │ ├─────────────────────┼───────┼───────────────────────────────┤ │ Add/Multiply │ 1x │ Baseline │ │ Divide │ 4x │ Avoid in loops │ │ Sqrt │ 4x │ Use rsqrt when possible │ │ Sin/Cos │ 8x │ Use lookup tables on mobile │ │ Texture Sample │ 4-8x │ Varies by hardware │ │ Pow │ 8x │ Use exp2(x*log2(y)) │ │ Normalize │ 4x │ Pre-normalize in vertex │ └─────────────────────┴───────┴───────────────────────────────┘
🔧 Troubleshooting ┌─────────────────────────────────────────────────────────────┐ │ PROBLEM: Shader not compiling │ ├─────────────────────────────────────────────────────────────┤ │ SOLUTIONS: │ │ → Check for syntax errors (missing semicolons) │ │ → Verify all variables are declared │ │ → Check target platform compatibility │ │ → Look for mismatched semantics │ └─────────────────────────────────────────────────────────────┘
┌─────────────────────────────────────────────────────────────┐ │ PROBLEM: Pink/magenta material │ ├─────────────────────────────────────────────────────────────┤ │ SOLUTIONS: │ │ → Shader failed to compile - check console │ │ → Missing shader on target platform │ │ → Add fallback shader │ │ → Check render pipeline compatibility │ └─────────────────────────────────────────────────────────────┘
┌─────────────────────────────────────────────────────────────┐ │ PROBLEM: Shader too slow │ ├─────────────────────────────────────────────────────────────┤ │ SOLUTIONS: │ │ → Profile with GPU debugger (RenderDoc) │ │ → Reduce texture samples │ │ → Use lower precision │ │ → Simplify math operations │ │ → Move calculations to vertex shader │ └─────────────────────────────────────────────────────────────┘
┌─────────────────────────────────────────────────────────────┐ │ PROBLEM: Too many shader variants │ ├─────────────────────────────────────────────────────────────┤ │ SOLUTIONS: │ │ → Use shader_feature instead of multi_compile │ │ → Strip unused variants in build settings │ │ → Combine keywords where possible │ │ → Use material property blocks │ └─────────────────────────────────────────────────────────────┘
Shader Languages by Engine Engine Language Notes Unity URP/HDRP HLSL + ShaderGraph Visual + code Unity Built-in CG/HLSL Legacy surface shaders Unreal HLSL + Material Editor Node-based preferred Godot Godot Shading Language Similar to GLSL OpenGL GLSL Cross-platform DirectX HLSL Windows/Xbox Vulkan SPIR-V (from GLSL) Low-level
Use this skill: When creating custom visuals, optimizing rendering, or implementing advanced effects.