Article directory
- Preface
- 1. Let’s first understand how Shader Graph operates.
-
- 1. Understand the panel information of Shader Graph
- 2. Modify the Shader path
- 3. Middle mouse button or Alt + left mouse button to move the canvas
- 4. Right-click the mouse to open the Create Node menu.
- 5. Convert ShaderGraph nodes into Shader code
- 6. It can be seen that the general framework of URP and BuildIn RP is consistent
- 2. The Shader after converting ShaderGraph only retains the most basic universal forward rendering pass.
Preface
In the previous article, we learned about Shader writing under BuildIn Render Pipeline in ShaderLab. In this article, let's take a look at how to write the simplest Shader under URP.
1. Let’s first understand how Shader Graph operates.
1. Understand the panel information of Shader Graph
2. Modify the Shader path
3. Middle mouse button or Alt + left mouse button to move the canvas
4. Right-click the mouse to open the Create Node menu.
5. Convert ShaderGraph nodes into Shader code
- You can directly view or copy the compiled Shader
6. It can be seen that the general framework of URP and BuildIn RP is consistent
2. The Shader after converting ShaderGraph only retains the most basic universal forward rendering pass.
因为是由ShaderGraph转化过来的。所以，这里虽然简化了。但是，还是过于臃肿，在之后的文章中，我们来优化一下
Shader "MyShader/P2_10"
{
Properties {}
SubShader
{
Tags
{
"RenderPipeline"="UniversalPipeline"
"RenderType"="Opaque"
"Queue"="Geometry"
}
Pass
{
Name "Universal Forward"
Tags
{
// LightMode: <None>
}
// Render State
Cull Back
Blend One Zero
ZTest LEqual
ZWrite On
// Debug
// <None>
// --------------------------------------------------
// Pass
HLSLPROGRAM
// Pragmas
#pragma target 2.0
#pragma multi_compile_instancing
#pragma multi_compile_fog
#pragma instancing_options renderinglayer
#pragma vertex vert
#pragma fragment frag
// Keywords
#pragma multi_compile _ LIGHTMAP_ON
#pragma multi_compile _ DIRLIGHTMAP_COMBINED
#pragma shader_feature _ _SAMPLE_GI
#pragma multi_compile_fragment _ _DBUFFER_MRT1 _DBUFFER_MRT2 _DBUFFER_MRT3
#pragma multi_compile_fragment _ DEBUG_DISPLAY
#pragma multi_compile_fragment _ _SCREEN_SPACE_OCCLUSION
// GraphKeywords: <None>
// Defines
#define ATTRIBUTES_NEED_NORMAL
#define ATTRIBUTES_NEED_TANGENT
#define VARYINGS_NEED_POSITION_WS
#define VARYINGS_NEED_NORMAL_WS
#define FEATURES_GRAPH_VERTEX
/* WARNING: $splice Could not find named fragment 'PassInstancing' */
#define SHADERPASS SHADERPASS_UNLIT
#define _FOG_FRAGMENT 1
/* WARNING: $splice Could not find named fragment 'DotsInstancingVars' */
// custom interpolator pre-include
/* WARNING: $splice Could not find named fragment 'sgci_CustomInterpolatorPreInclude' */
// Includes
#include "Packages/com.unity.render-pipelines.core/ShaderLibrary/Color.hlsl"
#include "Packages/com.unity.render-pipelines.core/ShaderLibrary/Texture.hlsl"
#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Lighting.hlsl"
#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Input.hlsl"
#include "Packages/com.unity.render-pipelines.core/ShaderLibrary/TextureStack.hlsl"
#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/ShaderGraphFunctions.hlsl"
#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/DBuffer.hlsl"
#include "Packages/com.unity.render-pipelines.universal/Editor/ShaderGraph/Includes/ShaderPass.hlsl"
// --------------------------------------------------
// Structs and Packing
// custom interpolators pre packing
/* WARNING: $splice Could not find named fragment 'CustomInterpolatorPrePacking' */
struct Attributes
{
float3 positionOS : POSITION;
float3 normalOS : NORMAL;
float4 tangentOS : TANGENT;
#if UNITY_ANY_INSTANCING_ENABLED
uint instanceID : INSTANCEID_SEMANTIC;
#endif
};
struct Varyings
{
float4 positionCS : SV_POSITION;
float3 positionWS;
float3 normalWS;
#if UNITY_ANY_INSTANCING_ENABLED
uint instanceID : CUSTOM_INSTANCE_ID;
#endif
#if (defined(UNITY_STEREO_MULTIVIEW_ENABLED)) || (defined(UNITY_STEREO_INSTANCING_ENABLED) && (defined(SHADER_API_GLES3) || defined(SHADER_API_GLCORE)))
uint stereoTargetEyeIndexAsBlendIdx0 : BLENDINDICES0;
#endif
#if (defined(UNITY_STEREO_INSTANCING_ENABLED))
uint stereoTargetEyeIndexAsRTArrayIdx : SV_RenderTargetArrayIndex;
#endif
#if defined(SHADER_STAGE_FRAGMENT) && defined(VARYINGS_NEED_CULLFACE)
FRONT_FACE_TYPE cullFace : FRONT_FACE_SEMANTIC;
#endif
};
struct SurfaceDescriptionInputs
{
};
struct VertexDescriptionInputs
{
float3 ObjectSpaceNormal;
float3 ObjectSpaceTangent;
float3 ObjectSpacePosition;
};
struct PackedVaryings
{
float4 positionCS : SV_POSITION;
float3 positionWS : INTERP0;
float3 normalWS : INTERP1;
#if UNITY_ANY_INSTANCING_ENABLED
uint instanceID : CUSTOM_INSTANCE_ID;
#endif
#if (defined(UNITY_STEREO_MULTIVIEW_ENABLED)) || (defined(UNITY_STEREO_INSTANCING_ENABLED) && (defined(SHADER_API_GLES3) || defined(SHADER_API_GLCORE)))
uint stereoTargetEyeIndexAsBlendIdx0 : BLENDINDICES0;
#endif
#if (defined(UNITY_STEREO_INSTANCING_ENABLED))
uint stereoTargetEyeIndexAsRTArrayIdx : SV_RenderTargetArrayIndex;
#endif
#if defined(SHADER_STAGE_FRAGMENT) && defined(VARYINGS_NEED_CULLFACE)
FRONT_FACE_TYPE cullFace : FRONT_FACE_SEMANTIC;
#endif
};
PackedVaryings PackVaryings(Varyings input)
{
PackedVaryings output;
ZERO_INITIALIZE(PackedVaryings, output);
output.positionCS = input.positionCS;
output.positionWS.xyz = input.positionWS;
output.normalWS.xyz = input.normalWS;
#if UNITY_ANY_INSTANCING_ENABLED
output.instanceID = input.instanceID;
#endif
#if (defined(UNITY_STEREO_MULTIVIEW_ENABLED)) || (defined(UNITY_STEREO_INSTANCING_ENABLED) && (defined(SHADER_API_GLES3) || defined(SHADER_API_GLCORE)))
output.stereoTargetEyeIndexAsBlendIdx0 = input.stereoTargetEyeIndexAsBlendIdx0;
#endif
#if (defined(UNITY_STEREO_INSTANCING_ENABLED))
output.stereoTargetEyeIndexAsRTArrayIdx = input.stereoTargetEyeIndexAsRTArrayIdx;
#endif
#if defined(SHADER_STAGE_FRAGMENT) && defined(VARYINGS_NEED_CULLFACE)
output.cullFace = input.cullFace;
#endif
return output;
}
Varyings UnpackVaryings(PackedVaryings input)
{
Varyings output;
output.positionCS = input.positionCS;
output.positionWS = input.positionWS.xyz;
output.normalWS = input.normalWS.xyz;
#if UNITY_ANY_INSTANCING_ENABLED
output.instanceID = input.instanceID;
#endif
#if (defined(UNITY_STEREO_MULTIVIEW_ENABLED)) || (defined(UNITY_STEREO_INSTANCING_ENABLED) && (defined(SHADER_API_GLES3) || defined(SHADER_API_GLCORE)))
output.stereoTargetEyeIndexAsBlendIdx0 = input.stereoTargetEyeIndexAsBlendIdx0;
#endif
#if (defined(UNITY_STEREO_INSTANCING_ENABLED))
output.stereoTargetEyeIndexAsRTArrayIdx = input.stereoTargetEyeIndexAsRTArrayIdx;
#endif
#if defined(SHADER_STAGE_FRAGMENT) && defined(VARYINGS_NEED_CULLFACE)
output.cullFace = input.cullFace;
#endif
return output;
}
// --------------------------------------------------
// Graph
// Graph Properties
CBUFFER_START(UnityPerMaterial)
CBUFFER_END
// Object and Global properties
// Graph Includes
// GraphIncludes: <None>
// -- Property used by ScenePickingPass
#ifdef SCENEPICKINGPASS
float4 _SelectionID;
#endif
// -- Properties used by SceneSelectionPass
#ifdef SCENESELECTIONPASS
int _ObjectId;
int _PassValue;
#endif
// Graph Functions
// GraphFunctions: <None>
// Custom interpolators pre vertex
/* WARNING: $splice Could not find named fragment 'CustomInterpolatorPreVertex' */
// Graph Vertex
struct VertexDescription
{
float3 Position;
float3 Normal;
float3 Tangent;
};
VertexDescription VertexDescriptionFunction(VertexDescriptionInputs IN)
{
VertexDescription description = (VertexDescription)0;
description.Position = IN.ObjectSpacePosition;
description.Normal = IN.ObjectSpaceNormal;
description.Tangent = IN.ObjectSpaceTangent;
return description;
}
// Custom interpolators, pre surface
#ifdef FEATURES_GRAPH_VERTEX
Varyings CustomInterpolatorPassThroughFunc(inout Varyings output, VertexDescription input)
{
return output;
}
#define CUSTOMINTERPOLATOR_VARYPASSTHROUGH_FUNC
#endif
// Graph Pixel
struct SurfaceDescription
{
float3 BaseColor;
};
SurfaceDescription SurfaceDescriptionFunction(SurfaceDescriptionInputs IN)
{
SurfaceDescription surface = (SurfaceDescription)0;
surface.BaseColor = IsGammaSpace() ? float3(0.5, 0.5, 0.5) : SRGBToLinear(float3(0.5, 0.5, 0.5));
return surface;
}
// --------------------------------------------------
// Build Graph Inputs
#ifdef HAVE_VFX_MODIFICATION
#define VFX_SRP_ATTRIBUTES Attributes
#define VFX_SRP_VARYINGS Varyings
#define VFX_SRP_SURFACE_INPUTS SurfaceDescriptionInputs
#endif
VertexDescriptionInputs BuildVertexDescriptionInputs(Attributes input)
{
VertexDescriptionInputs output;
ZERO_INITIALIZE(VertexDescriptionInputs, output);
output.ObjectSpaceNormal = input.normalOS;
output.ObjectSpaceTangent = input.tangentOS.xyz;
output.ObjectSpacePosition = input.positionOS;
return output;
}
SurfaceDescriptionInputs BuildSurfaceDescriptionInputs(Varyings input)
{
SurfaceDescriptionInputs output;
ZERO_INITIALIZE(SurfaceDescriptionInputs, output);
#ifdef HAVE_VFX_MODIFICATION
#if VFX_USE_GRAPH_VALUES
uint instanceActiveIndex = asuint(UNITY_ACCESS_INSTANCED_PROP(PerInstance, _InstanceActiveIndex));
/* WARNING: $splice Could not find named fragment 'VFXLoadGraphValues' */
#endif
/* WARNING: $splice Could not find named fragment 'VFXSetFragInputs' */
#endif
#if UNITY_UV_STARTS_AT_TOP
#else
#endif
#if defined(SHADER_STAGE_FRAGMENT) && defined(VARYINGS_NEED_CULLFACE)
#define BUILD_SURFACE_DESCRIPTION_INPUTS_OUTPUT_FACESIGN output.FaceSign = IS_FRONT_VFACE(input.cullFace, true, false);
#else
#define BUILD_SURFACE_DESCRIPTION_INPUTS_OUTPUT_FACESIGN
#endif
#undef BUILD_SURFACE_DESCRIPTION_INPUTS_OUTPUT_FACESIGN
return output;
}
// --------------------------------------------------
// Main
#include "Packages/com.unity.render-pipelines.universal/Editor/ShaderGraph/Includes/Varyings.hlsl"
#include "Packages/com.unity.render-pipelines.universal/Editor/ShaderGraph/Includes/UnlitPass.hlsl"
// --------------------------------------------------
// Visual Effect Vertex Invocations
#ifdef HAVE_VFX_MODIFICATION
#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/VisualEffectVertex.hlsl"
#endif
ENDHLSL
}
}
FallBack "Hidden/Shader Graph/FallbackError"
}
1. Let’s take a look at the default Shader used after URP Pass is unavailable.
使用的是内置渲染管线，返回颜色为洋葱紫
Shader "Hidden/Universal Render Pipeline/FallbackError"
{
SubShader
{
Tags
{
"RenderType" = "Opaque"
"RenderPipeline" = "UniversalPipeline"
"IgnoreProjector" = "True"
}
Pass
{
HLSLPROGRAM
#pragma target 2.0
#pragma editor_sync_compilation
// -------------------------------------
// Shader Stages
#pragma vertex vert
#pragma fragment frag
// -------------------------------------
// Unity defined keywords
#pragma multi_compile _ STEREO_INSTANCING_ON STEREO_MULTIVIEW_ON
//--------------------------------------
// GPU Instancing
#include_with_pragmas "Packages/com.unity.render-pipelines.universal/ShaderLibrary/DOTS.hlsl"
// -------------------------------------
// Includes
#include "Packages/com.unity.render-pipelines.core/ShaderLibrary/Common.hlsl"
#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Input.hlsl"
struct appdata_t
{
float4 vertex : POSITION;
UNITY_VERTEX_INPUT_INSTANCE_ID
};
struct v2f
{
float4 vertex : SV_POSITION;
UNITY_VERTEX_OUTPUT_STEREO
};
v2f vert (appdata_t v)
{
v2f o;
UNITY_SETUP_INSTANCE_ID(v);
UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
o.vertex = TransformObjectToHClip(v.vertex.xyz);
return o;
}
float4 frag (v2f i) : SV_Target
{
return float4(1,0,1,1);
}
ENDHLSL
}
}
Fallback "Hidden/Core/FallbackError"
}