Improvements to artistic nodes.

- Added the fuzziness slot to ReplaceColorNode and ColorMaskNode. It works like
  the fuzziness parameter in Photoshop that gives softer edges to the mask.
- Changed the output format of ColorMaskNode from Vector3 to Vector1. It only
  outputs single channel masks.
- Added the opacity slot to BlendNode. It's useful when one tries using
  BlendNode like layers in Photoshop.

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Data/Nodes/Artistic/Adjustment/ReplaceColorNode.cs

             [Slot(1, Binding.None)] ColorRGB From,
             [Slot(2, Binding.None)] ColorRGB To,
             [Slot(3, Binding.None)] Vector1 Range,
-            [Slot(4, Binding.None)] out Vector3 Out)
+            [Slot(4, Binding.None)] Vector1 Fuzziness,
+            [Slot(5, Binding.None)] out Vector3 Out)
-            Out = Vector2.zero;
+            Out = Vector3.zero;
-    {precision}3 col = In;
-    if(Distance <= Range)
-        col = To;
-    Out = col;
+    Out = lerp(To, In, saturate((Distance - Range) / max(Fuzziness, 1e-5f)));
 }";
         }
     }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Data/Nodes/Artistic/Blend/BlendNode.cs

         static string Unity_Blend_Burn(
             [Slot(0, Binding.None)] DynamicDimensionVector Base,
             [Slot(1, Binding.None)] DynamicDimensionVector Blend,
-            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+            [Slot(2, Binding.None)] Vector1 Opacity,
+            [Slot(3, Binding.None)] out DynamicDimensionVector Out)
+    Out = lerp(Base, Out, Opacity);
 }";
         }
 
-            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+            [Slot(2, Binding.None)] Vector1 Opacity,
+            [Slot(3, Binding.None)] out DynamicDimensionVector Out)
+    Out = lerp(Base, Out, Opacity);
 }";
         }
 
-            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+            [Slot(2, Binding.None)] Vector1 Opacity,
+            [Slot(3, Binding.None)] out DynamicDimensionVector Out)
+    Out = lerp(Base, Out, Opacity);
 }";
         }
 
-            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+            [Slot(2, Binding.None)] Vector1 Opacity,
+            [Slot(3, Binding.None)] out DynamicDimensionVector Out)
+    Out = lerp(Base, Out, Opacity);
 }";
         }
 
-            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+            [Slot(2, Binding.None)] Vector1 Opacity,
+            [Slot(3, Binding.None)] out DynamicDimensionVector Out)
+    Out = lerp(Base, Out, Opacity);
 }";
         }
 
-            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+            [Slot(2, Binding.None)] Vector1 Opacity,
+            [Slot(3, Binding.None)] out DynamicDimensionVector Out)
+    Out = lerp(Base, Out, Opacity);
 }";
         }
 
-            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+            [Slot(2, Binding.None)] Vector1 Opacity,
+            [Slot(3, Binding.None)] out DynamicDimensionVector Out)
-    {precision}{slot2dimension} result1 = 1.0 - 2.0 * (1.0 - Base) * (1.0 - Blend);
-    {precision}{slot2dimension} result2 = 2.0 * Base * Blend;
-    {precision}{slot2dimension} zeroOrOne = step(Blend, 0.5);
+    {precision}{slot3dimension} result1 = 1.0 - 2.0 * (1.0 - Base) * (1.0 - Blend);
+    {precision}{slot3dimension} result2 = 2.0 * Base * Blend;
+    {precision}{slot3dimension} zeroOrOne = step(Blend, 0.5);
+    Out = lerp(Base, Out, Opacity);
 }";
         }
 
-            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+            [Slot(2, Binding.None)] Vector1 Opacity,
+            [Slot(3, Binding.None)] out DynamicDimensionVector Out)
+    Out = lerp(Base, Out, Opacity);
 }";
         }
 
-            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+            [Slot(2, Binding.None)] Vector1 Opacity,
+            [Slot(3, Binding.None)] out DynamicDimensionVector Out)
+    Out = lerp(Base, Out, Opacity);
 }";
         }
 
-            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+            [Slot(2, Binding.None)] Vector1 Opacity,
+            [Slot(3, Binding.None)] out DynamicDimensionVector Out)
+    Out = lerp(Base, Out, Opacity);
 }";
         }
 
-            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+            [Slot(2, Binding.None)] Vector1 Opacity,
+            [Slot(3, Binding.None)] out DynamicDimensionVector Out)
+    Out = lerp(Base, Out, Opacity);
 }";
         }
 
-            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+            [Slot(2, Binding.None)] Vector1 Opacity,
+            [Slot(3, Binding.None)] out DynamicDimensionVector Out)
+    Out = lerp(Base, Out, Opacity);
 }";
         }
 
-            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+            [Slot(2, Binding.None)] Vector1 Opacity,
+            [Slot(3, Binding.None)] out DynamicDimensionVector Out)
+    Out = lerp(Base, Out, Opacity);
 }";
         }
 
-            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+            [Slot(2, Binding.None)] Vector1 Opacity,
+            [Slot(3, Binding.None)] out DynamicDimensionVector Out)
+    Out = lerp(Base, Out, Opacity);
 }";
         }
 
-            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+            [Slot(2, Binding.None)] Vector1 Opacity,
+            [Slot(3, Binding.None)] out DynamicDimensionVector Out)
+    Out = lerp(Base, Out, Opacity);
 }";
         }
 
-            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+            [Slot(2, Binding.None)] Vector1 Opacity,
+            [Slot(3, Binding.None)] out DynamicDimensionVector Out)
+    Out = lerp(Base, Out, Opacity);
 }";
         }
 
-            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+            [Slot(2, Binding.None)] Vector1 Opacity,
+            [Slot(3, Binding.None)] out DynamicDimensionVector Out)
-    {precision}{slot2dimension} result1 = 1.0 - 2.0 * (1.0 - Base) * (1.0 - Blend);
-    {precision}{slot2dimension} result2 = 2.0 * Base * Blend;
-    {precision}{slot2dimension} zeroOrOne = step(Base, 0.5);
+    {precision}{slot3dimension} result1 = 1.0 - 2.0 * (1.0 - Base) * (1.0 - Blend);
+    {precision}{slot3dimension} result2 = 2.0 * Base * Blend;
+    {precision}{slot3dimension} zeroOrOne = step(Base, 0.5);
+    Out = lerp(Base, Out, Opacity);
 }
 ";
         }
             [Slot(1, Binding.None)] DynamicDimensionVector Blend,
-            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+            [Slot(2, Binding.None)] Vector1 Opacity,
+            [Slot(3, Binding.None)] out DynamicDimensionVector Out)
-    {precision}{slot2dimension} check = step (0.5, Blend);
-    {precision}{slot2dimension} result1 = check * max(2.0 * (Base - 0.5), Blend);
+    {precision}{slot3dimension} check = step (0.5, Blend);
+    {precision}{slot3dimension} result1 = check * max(2.0 * (Base - 0.5), Blend);
+    Out = lerp(Base, Out, Opacity);
 }
 ";
         }
             [Slot(1, Binding.None)] DynamicDimensionVector Blend,
-            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+            [Slot(2, Binding.None)] Vector1 Opacity,
+            [Slot(3, Binding.None)] out DynamicDimensionVector Out)
-    {precision}{slot2dimension} result1 = 2.0 * Base * Blend + Base * Base * (1.0 - 2.0 * Blend);
-    {precision}{slot2dimension} result2 = sqrt(Base) * (2.0 * Blend - 1.0) + 2.0 * Base * (1.0 - Blend);
-    {precision}{slot2dimension} zeroOrOne = step(0.5, Blend);
+    {precision}{slot3dimension} result1 = 2.0 * Base * Blend + Base * Base * (1.0 - 2.0 * Blend);
+    {precision}{slot3dimension} result2 = sqrt(Base) * (2.0 * Blend - 1.0) + 2.0 * Base * (1.0 - Blend);
+    {precision}{slot3dimension} zeroOrOne = step(0.5, Blend);
+    Out = lerp(Base, Out, Opacity);
 }
 ";
         }
             [Slot(1, Binding.None)] DynamicDimensionVector Blend,
-            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+            [Slot(2, Binding.None)] Vector1 Opacity,
+            [Slot(3, Binding.None)] out DynamicDimensionVector Out)
-    {precision}{slot2dimension} result1 = 1.0 - (1.0 - Blend) / (2.0 * Base);
-    {precision}{slot2dimension} result2 = Blend / (2.0 * (1.0 - Base));
-    {precision}{slot2dimension} zeroOrOne = step(0.5, Base);
+    {precision}{slot3dimension} result1 = 1.0 - (1.0 - Blend) / (2.0 * Base);
+    {precision}{slot3dimension} result2 = Blend / (2.0 * (1.0 - Base));
+    {precision}{slot3dimension} zeroOrOne = step(0.5, Base);
+    Out = lerp(Base, Out, Opacity);
 }
 ";
         }
             [Slot(1, Binding.None)] DynamicDimensionVector Blend,
-            [Slot(2, Binding.None)] out DynamicDimensionVector Out)
+            [Slot(2, Binding.None)] Vector1 Opacity,
+            [Slot(3, Binding.None)] out DynamicDimensionVector Out)
+    Out = lerp(Base, Out, Opacity);
 }
 ";
         }

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Data/Nodes/Artistic/Mask/ColorMaskNode.cs

             [Slot(0, Binding.None)] Vector3 In,
             [Slot(1, Binding.None)] ColorRGB MaskColor,
             [Slot(2, Binding.None)] Vector1 Range,
-            [Slot(3, Binding.None)] out Vector3 Out)
+            [Slot(3, Binding.None)] Vector1 Fuzziness,
+            [Slot(4, Binding.None)] out Vector1 Out)
-            Out = Vector3.zero;
-    {precision}3 col = {precision}3(0, 0, 0);
-    if(Distance <= Range)
-        col = {precision}3(1, 1, 1);
-    Out = col;
+    Out = saturate(1 - (Distance - Range) / max(Fuzziness, 1e-5));
 }";
         }
     }