定制ShaderGraph(一)---创建干净的底板

定制ShaderGraph(一)—创建干净的底板

00 前置知识

功能入口

通过搜索Assets/Create/Shader Graph/URP/我们能够找到功能的关键入口类

• CreateLitShaderGraph

  路径: Library/PackageCache/com.unity.render-pipelines.universal@12.1.10/Editor/ShaderGraph/AssetCallbacks/CreateLitShaderGraph.cs

  static class CreateLitShaderGraph
      {
          [MenuItem("Assets/Create/Shader Graph/URP/Lit Shader Graph", priority = CoreUtils.Priorities.assetsCreateShaderMenuPriority)]
          public static void CreateLitGraph()
          {
              var target = (UniversalTarget)Activator.CreateInstance(typeof(UniversalTarget));
              target.TrySetActiveSubTarget(typeof(UniversalLitSubTarget));
    
              var blockDescriptors = new[]
              {
                  BlockFields.VertexDescription.Position,
                  BlockFields.VertexDescription.Normal,
                  BlockFields.VertexDescription.Tangent,
                  BlockFields.SurfaceDescription.BaseColor,
                  BlockFields.SurfaceDescription.NormalTS,
                  BlockFields.SurfaceDescription.Metallic,
                  BlockFields.SurfaceDescription.Smoothness,
                  BlockFields.SurfaceDescription.Emission,
                  BlockFields.SurfaceDescription.Occlusion,
              };
    
              GraphUtil.CreateNewGraphWithOutputs(new[] { target }, blockDescriptors);
          }
      }
  

  可以看到, 实际创建的是一个UniversalTarget, 然后通过TrySetActiveSubTarget()方法去将m_ActiveSubTarget赋值为subTarget,

  然后输入blockDescriptors数组就可以构建出最初状态的ShaderGraph着色器.

关键类

• SubTarget, SubTarget<T>

  路径: Library/PackageCache/com.unity.shadergraph@12.1.10/Editor/Generation/SubTarget.cs

• UniversalTarget

  路径: Library/PackageCache/com.unity.render-pipelines.universal@12.1.10/Editor/ShaderGraph/Targets/UniversalTarget.cs

• UniversalLitSubTarget

  路径: Library/PackageCache/com.unity.render-pipelines.universal@12.1.10/Editor/ShaderGraph/Targets/UniversalLitSubTarget.cs

01 实施

• 拷贝关键类CreateLitShaderGraph, UniversalLitSubTarget

• 制作自己的CreateVehiclePaintShaderGraph类

  static class CreateVehiclePaintShaderGraph
      {
          [MenuItem("Assets/Create/Shader Graph/URP/Vehicle Paint Shader Graph", priority = CoreUtils.Priorities.assetsCreateShaderMenuPriority)]
          public static void CreateVehicleGraph()
          {
              // 基版使用UniversalTarget
              var target = (UniversalTarget)Activator.CreateInstance(typeof(UniversalTarget));
              // SubTarget里面放定制需求
              target.TrySetActiveSubTarget(typeof(UniversalVehiclePaintSubTarget));
                
              // 定义block块
              var blockDescriptors = new[]
              {
                  BlockFields.VertexDescription.Position,
                  BlockFields.VertexDescription.Normal,
                  BlockFields.VertexDescription.Tangent,
                  BlockFields.SurfaceDescription.BaseColor,
                  BlockFields.SurfaceDescription.NormalTS,
                  BlockFields.SurfaceDescription.Metallic,
                  BlockFields.SurfaceDescription.Smoothness,
                  BlockFields.SurfaceDescription.Emission,
                  BlockFields.SurfaceDescription.Occlusion,
              };
    
              // 创建对象
              GraphUtil.CreateNewGraphWithOutputs(new Target[] { target }, blockDescriptors);
          }
    
      }
  

• 制作自己的UniversalVehiclePaintSubTarget类, 替换掉guid, 并替换掉名称即可

  static readonly GUID kSourceCodeGuid = new GUID("4443eec7cc6a454c86378894f2e8a868"); // UniversalVehiclePaintSubTarget.cs
  ...
  public UniversalVehiclePaintSubTarget()
  {
      // ShaderGraph 的 Material 栏中显示的名字
      displayName = "VehiclePaint";
  }
  

  然后我们就得到了一个可以修改的模板, 并可以在ShaderGraph中选择, 并且在右键菜单进行创建.

  

  

• 还可以把里面的各个Region分离为单独的类, 以免整个类太大

  最终我分拆出了这些

  

参考网页