Step1 for LevelNode

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/MaterialGraphPresenter.cs

             typeMapper[typeof(MasterRemapInputNode)] = typeof(RemapInputNodePresenter);
             typeMapper[typeof(AbstractSubGraphIONode)] = typeof(SubgraphIONodePresenter);
             typeMapper[typeof(AbstractSurfaceMasterNode)] = typeof(SurfaceMasterPresenter);
+            typeMapper[typeof(LevelNode)] = typeof(LevelNodePresenter);
         }
     }
 }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/LevelNodePresenter.cs

+using System;
+using System.Collections.Generic;
+using RMGUI.GraphView;
+using UnityEditor.Graphing.Drawing;
+using UnityEngine.MaterialGraph;
+
+namespace UnityEditor.MaterialGraph.Drawing
+{
+    class LevelControlPresenter : GraphControlPresenter
+    {
+        public override void OnGUIHandler()
+        {
+            base.OnGUIHandler();
+
+            var tNode = node as LevelNode;
+            if (tNode == null)
+                return;
+
+            tNode.inputMin   = EditorGUILayout.FloatField("InputMin:", tNode.inputMin);
+            tNode.inputMax   = EditorGUILayout.FloatField("InputMax:", tNode.inputMax);
+            tNode.inputGamma = EditorGUILayout.FloatField("InputGamma:", tNode.inputGamma);
+            tNode.outputMin  = EditorGUILayout.FloatField("OutputMin:", tNode.outputMin);
+            tNode.outputMax  = EditorGUILayout.FloatField("OutputMax:", tNode.outputMax);
+        }
+
+        public override float GetHeight()
+        {
+            return (EditorGUIUtility.singleLineHeight * 5 + EditorGUIUtility.standardVerticalSpacing) + EditorGUIUtility.standardVerticalSpacing;
+        }
+    }
+
+    [Serializable]
+    public class LevelNodePresenter : PropertyNodePresenter
+    {
+        protected override IEnumerable<GraphElementPresenter> GetControlData()
+        {
+            var instance = CreateInstance<LevelControlPresenter>();
+            instance.Initialize(node);
+            return new List<GraphElementPresenter>(base.GetControlData()) { instance };
+        }
+    }
+}

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Drawing/Presenters/LevelNodePresenter.cs.meta

+fileFormatVersion: 2
+guid: 224a0b135d08f2c46a9486ae3e9fb082
+timeCreated: 1495457202
+licenseType: Pro
+MonoImporter:
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

MaterialGraphProject/Assets/UnityShaderEditor/Runtime/Nodes/LevelNode.cs

+namespace UnityEngine.MaterialGraph
+{
+    [Title("Art/Level Node")]
+    public class LevelNode : Function1Input, IGeneratesFunction
+    {
+        [SerializeField]
+        private float m_InputMin = 0.0f;
+        [SerializeField]
+        private float m_InputMax = 1.0f;
+        [SerializeField]
+        private float m_InputGamma = 1.0f;
+        [SerializeField]
+        private float m_OutputMin = 0.0f;
+        [SerializeField]
+        private float m_OutputMax = 1.0f;
+
+        public float inputMin
+        {
+            get { return m_InputMin; }
+            set { m_InputMin = value; }
+        }
+
+        public float inputMax
+        {
+            get { return m_InputMax; }
+            set { m_InputMax = value; }
+        }
+
+        public float inputGamma
+        {
+            get { return m_InputGamma; }
+            set { m_InputGamma = value; }
+        }
+
+        public float outputMin
+        {
+            get { return m_OutputMin; }
+            set { m_OutputMin = value; }
+        }
+
+        public float outputMax
+        {
+            get { return m_OutputMax; }
+            set { m_OutputMax = value; }
+        }
+
+        public LevelNode()
+        {
+            name = "LevelNode";
+        }
+
+        protected override string GetFunctionName()
+        {
+            return "unity_level_" + precision;
+        }
+
+        protected override string GetFunctionCallBody(string inputValue)
+        {
+            float inputInvGamma = 1.0f / m_InputGamma;
+            return GetFunctionName() + "(" + inputValue + ", " + m_InputMin + ", " + m_InputMax + ", " + inputInvGamma + ", " + m_OutputMin + ", " + m_OutputMax + ")";
+        }
+
+        public void GenerateNodeFunction(ShaderGenerator visitor, GenerationMode generationMode)
+        {
+            var outputString = new ShaderGenerator();
+            outputString.AddShaderChunk("inline " + precision + outputDimension + " unity_level_" + precision + " (" + precision + outputDimension + " arg1, "
+                                        + precision + " inputMin, "
+                                        + precision + " inputMax, "
+                                        + precision + " inputInvGamma, "
+                                        + precision + " outputMin, "
+                                        + precision + " outputMax)", false);
+            outputString.AddShaderChunk("{", false);
+            outputString.Indent();
+            outputString.AddShaderChunk(precision + inputDimension + " colorMinClamped = max(arg1 - inputMin, 0.0);", false);
+            outputString.AddShaderChunk(precision + inputDimension + " colorMinMaxClamped = min(colorMinClamped / (inputMax - inputMin), 1.0);", false);
+            outputString.AddShaderChunk("return lerp(outputMin, outputMax, pow(colorMinMaxClamped, inputInvGamma));", false);
+
+            outputString.Deindent();
+            outputString.AddShaderChunk("}", false);
+
+            visitor.AddShaderChunk(outputString.GetShaderString(0), true);
+        }
+    }
+}

MaterialGraphProject/Assets/UnityShaderEditor/Runtime/Nodes/LevelNode.cs.meta

+fileFormatVersion: 2
+guid: afcb18d0b92d93d45a34c5699ed4ff49
+MonoImporter:
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: