URP (Universal Render Pipeline)

• 기존 Built-in(Legacy) 쉐이더의 include 경로 및 함수명등 바뀜
• SBR Batcher 사용가능하게 바뀜.
• 1패스 1라이트방식 => 1패스 16개 라이트 지원

https://unity.com/kr/resources/introduction-universal-render-pipeline-for-advanced-unity-creators-2022lts

sample

Varyings OUT;
ZERO_INITIALIZE(Varyings, OUT);

OUT.positionCS    = TransformObjectToHClip(IN.positionOS.xyz);
OUT.positionWS    = TransformObjectToWorld(IN.positionOS.xyz);
OUT.N             = TransformObjectToWorldNormal(IN.normal);
OUT.uv            = TRANSFORM_TEX(IN.uv, _MainTex);
OUT.fogCoord      = ComputeFogFactor(IN.positionOS.z);          // float
OUT.shadowCoord   = TransformWorldToShadowCoord(OUT.positionWS);// float4

VertexPositionInputs vertexInput = GetVertexPositionInputs(v.vertex.xyz);
OUT.shadowCoord = GetShadowCoord(vertexInput);

Light mainLight = GetMainLight();
Light mainLight = GetMainLight(shadowCoord);

half3 ambient = SampleSH(IN.normal);

half3 cameraWS = GetCameraPositionWS();

// GPU instancing
#pragma multi_compile_instancing

// Fog
#pragma multi_compile_fog

// Light & Shadow
#pragma multi_compile _ _MAIN_LIGHT_SHADOWS
#pragma multi_compile _ _MAIN_LIGHT_SHADOWS_CASCADE
#pragma multi_compile _ _ADDITIONAL_LIGHTS
#pragma multi_compile _ _ADDITIONAL_LIGHTS_CASCADE
#pragma multi_compile _ _SHADOWS_SOFT

// LightMap
#pragma multi_compile _ DIRLIGHTMAP_COMBINED
#pragma multi_compile _ LIGHTMAP_ON

SBR Batcher / GPU인스턴싱

SRP Batcher가 추가됨으로써, 동적오브젝트가 많아져도 좋은 퍼포먼스 유지하는게

• https://docs.unity3d.com/Manual/GPUInstancing.html

// For SRP Batcher

CBUFFER_START(UnityPerMaterial)
...
CBUFFER_END

// for GPU instancing

struct Attributes
{
    UNITY_VERTEX_INPUT_INSTANCE_ID
};

struct Varyings
{
    UNITY_VERTEX_INPUT_INSTANCE_ID
    UNITY_VERTEX_OUTPUT_STEREO // for VR
};

Varyings vert(Attributes IN)
{
    Varyings OUT;
    UNITY_SETUP_INSTANCE_ID(IN);
    UNITY_TRANSFER_INSTANCE_ID(IN, OUT); 
};

half4 frag(Varyings IN) : SV_Target
{
    UNITY_SETUP_INSTANCE_ID(IN); 
}

hlsl

com.unity.render-pipelines.core/ShaderLibrary

Common.hlsl

// com.unity.render-pipelines.core/ShaderLibrary/Common.hlsl

#elif defined(SHADER_API_D3D11)
#include "Packages/com.unity.render-pipelines.core/ShaderLibrary/API/D3D11.hlsl"

Macros.hlsl

// com.unity.render-pipelines.core/ShaderLibrary/Macros.hlsl

#define PI          3.14159265358979323846 // PI
#define TWO_PI      6.28318530717958647693 // 2 * PI
#define FOUR_PI     12.5663706143591729538 // 4 * PI
#define INV_PI      0.31830988618379067154 // 1 / PI
#define INV_TWO_PI  0.15915494309189533577 // 1 / (2 * PI)
#define INV_FOUR_PI 0.07957747154594766788 // 1 / (4 * PI)
#define HALF_PI     1.57079632679489661923 // PI / 2
#define INV_HALF_PI 0.63661977236758134308 // 2 / PI
#define LOG2_E      1.44269504088896340736 // log2e
#define INV_SQRT2   0.70710678118654752440 // 1 / sqrt(2)
#define PI_DIV_FOUR 0.78539816339744830961 // PI / 4

#define TRANSFORM_TEX(tex, name) ((tex.xy) * name##_ST.xy + name##_ST.zw)
#define GET_TEXELSIZE_NAME(name) (name##_TexelSize)

(U ,V)

V
(0,1)       (1,1)
   +----+----+
   |    |    |
   +----+----+
   |    |    |
   +----+----+
(0,0)       (1,0) U

API/(renderer).hlsl

// com.unity.render-pipelines.core/ShaderLibrary/API/D3D11.hlsl

#define CBUFFER_START(name) cbuffer name {
#define CBUFFER_END };

#define ZERO_INITIALIZE(type, name) name = (type)0;


#define TEXTURE2D(textureName)                Texture2D textureName
#define TEXTURE2D_ARRAY(textureName)          Texture2DArray textureName
#define TEXTURECUBE(textureName)              TextureCube textureName
#define SAMPLER(samplerName)                  SamplerState samplerName

#define SAMPLE_TEXTURE2D(textureName, samplerName, coord2)                               textureName.Sample(samplerName, coord2)
#define SAMPLE_TEXTURE2D_LOD(textureName, samplerName, coord2, lod)                      textureName.SampleLevel(samplerName, coord2, lod)

#define SAMPLE_TEXTURE2D_ARRAY(textureName, samplerName, coord2, index)                  textureName.Sample(samplerName, float3(coord2, index))
#define SAMPLE_TEXTURE2D_ARRAY_LOD(textureName, samplerName, coord2, index, lod)         textureName.SampleLevel(samplerName, float3(coord2, index), lod)

#define SAMPLE_TEXTURECUBE(textureName, samplerName, coord3)                             textureName.Sample(samplerName, coord3)
#define SAMPLE_TEXTURECUBE_LOD(textureName, samplerName, coord3, lod)                    textureName.SampleLevel(samplerName, coord3, lod)

#define SAMPLE_DEPTH_TEXTURE(textureName, samplerName, coord2)          SAMPLE_TEXTURE2D(textureName, samplerName, coord2).r
#define SAMPLE_DEPTH_TEXTURE_LOD(textureName, samplerName, coord2, lod) SAMPLE_TEXTURE2D_LOD(textureName, samplerName, coord2, lod).r

Packing.hlsl

// com.unity.render-pipelines.core/ShaderLibrary/Packing.hlsl
real3 UnpackNormal(real4 packedNormal)

com.unity.render-pipelines.universal/ShaderLibrary/

universal/ShaderLibrary/Core.hlsl

#include "Packages/com.unity.render-pipelines.core/ShaderLibrary/Packing.hlsl"

struct VertexPositionInputs
{
    float3 positionWS; // World space position
    float3 positionVS; // View space position
    float4 positionCS; // Homogeneous clip space position
    float4 positionNDC;// Homogeneous normalized device coordinates
};


struct VertexNormalInputs
{
    real3 tangentWS;
    real3 bitangentWS;
    float3 normalWS;
};

#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/ShaderVariablesFunctions.hlsl"

ShaderVariablesFunctions.hlsl

// com.unity.render-pipelines.universal/ShaderLibrary/ShaderVariablesFunctions.hlsl

VertexPositionInputs GetVertexPositionInputs(float3 positionOS)
{
    VertexPositionInputs input;
    input.positionWS = TransformObjectToWorld(positionOS);
    input.positionVS = TransformWorldToView(input.positionWS);
    input.positionCS = TransformWorldToHClip(input.positionWS);

    float4 ndc = input.positionCS * 0.5f;
    input.positionNDC.xy = float2(ndc.x, ndc.y * _ProjectionParams.x) + ndc.w;
    input.positionNDC.zw = input.positionCS.zw;

    return input;
}

VertexNormalInputs GetVertexNormalInputs(float3 normalOS)
VertexNormalInputs GetVertexNormalInputs(float3 normalOS, float4 tangentOS)

float3 GetCameraPositionWS()

float3 GetWorldSpaceViewDir(float3 positionWS)

real ComputeFogFactor(float z)

half3 MixFog(half3 fragColor, half fogFactor)

half LinearDepthToEyeDepth(half rawDepth)

SpaceTransforms.hlsl

// com.unity.render-pipelines.core/ShaderLibrary/SpaceTransforms.hlsl

float3 TransformObjectToWorld(float3 positionOS) // OS > WS
float4 TransformObjectToHClip(float3 positionOS) // OS > HCS

float3 TransformWorldToView(float3 positionWS)   // WS > VS
float4 TransformWViewToHClip(float3 positionVS)  // VS > HCS

float3 TransformWorldToObject(float3 positionWS) // WS > OS

float3 TransformObjectToWorldDir(float3 dirOS, bool doNormalize = true) // normalOS > normalWS

Varaiable