Unity Shader URP 学习《Built-in和URP中Unlit Shader的区别》

刚刚从Built-in过来看URP一脸懵逼，接下来开始总结两者的区别~~达到二脸懵逼~~。

Built-in ——>Unlit

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Shader "Unlit/NewUnlitShader"
{
Properties
{
_MainTex ("Texture", 2D) = "white" {}
}
SubShader
{
Tags { "RenderType"="Opaque" }
LOD 100

Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"

sampler2D _MainTex;
float4 _MainTex_ST;

struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};

struct v2f
{
float2 uv : TEXCOORD0;
float4 vertex : SV_POSITION;
};

v2f vert (appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = TRANSFORM_TEX(v.uv, _MainTex);

return o;
}

fixed4 frag (v2f i) : SV_Target
{

fixed4 col = tex2D(_MainTex, i.uv);
return col;
}
ENDCG
}
}
}

URP——>Unlit

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Shader "Universal Render Pipeline/Unlit"
{
Properties
{
_BaseMap("Texture", 2D) = "white" {}
_BaseColor("Color", Color) = (1, 1, 1, 1)
_Cutoff("AlphaCutout", Range(0.0, 1.0)) = 0.5
}
SubShader
{
Tags { "RenderType" = "Opaque" "IgnoreProjector" = "True" "RenderPipeline" = "UniversalPipeline" }
LOD 100

Pass
{
Name "Unlit"
HLSLPROGRAM
// Required to compile gles 2.0 with standard srp library
#pragma prefer_hlslcc gles
#pragma exclude_renderers d3d11_9x

#pragma vertex vert
#pragma fragment frag
#pragma shader_feature _ALPHATEST_ON
#pragma shader_feature _ALPHAPREMULTIPLY_ON

// -------------------------------------
// Unity defined keywords
#pragma multi_compile_instancing

#include "UnlitInput.hlsl"

struct Attributes
{
float4 positionOS : POSITION;
float2 uv : TEXCOORD0;
UNITY_VERTEX_INPUT_INSTANCE_ID
};

struct Varyings
{
float2 uv : TEXCOORD0;
float4 vertex : SV_POSITION;

UNITY_VERTEX_INPUT_INSTANCE_ID
UNITY_VERTEX_OUTPUT_STEREO
};

Varyings vert(Attributes input)
{
Varyings output = (Varyings)0;

UNITY_SETUP_INSTANCE_ID(input);
UNITY_TRANSFER_INSTANCE_ID(input, output);
UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(output);

VertexPositionInputs vertexInput =
GetVertexPositionInputs(input.positionOS.xyz);
output.vertex = vertexInput.positionCS;
output.uv = TRANSFORM_TEX(input.uv, _BaseMap);

return output;
}

half4 frag(Varyings input) : SV_Target
{
UNITY_SETUP_INSTANCE_ID(input);
UNITY_SETUP_STEREO_EYE_INDEX_POST_VERTEX(input);

half2 uv = input.uv;
half4 texColor = SAMPLE_TEXTURE2D(_BaseMap, sampler_BaseMap, uv);
half3 color = texColor.rgb * _BaseColor.rgb;
half alpha = texColor.a * _BaseColor.a;
AlphaDiscard(alpha, _Cutoff);

#ifdef _ALPHAPREMULTIPLY_ON
color *= alpha;
#endif

return half4(color, alpha);
}
ENDHLSL
}

}
FallBack "Hidden/Universal Render Pipeline/FallbackError"
CustomEditor "UnityEditor.Rendering.Universal.ShaderGUI.UnlitShader"
}

标签部分有了一个"RenderPipeline" = "UniversalPipeline"

如果要支持光照还有一个 Tags { "LightMode" = "UniversalForward" }是不能少的

多了各种#pragma 其中一些是库代码中的开关。

prefer_hlslcc gles 在OpenGL ES 2.0中使用HLSLcc编译器，目前除了OpenGL ES 2.0全都默认使用HLSLcc编译器

exclude_renderers d3d11_9x 在Direct3D 11 9.x功能级别的渲染平台中不编译Shader

# include "UnityCG.cginc"没了取而代之的是#include "UnlitInput.hlsl"，

"UnlitInput.hlsl"它又引用了SurfaceInput.hlsl，

SurfaceInput.hlsl又引入了Core.hlsl、Packing.hlsl、CommonMateral.hlsl（开始套娃）