Fix case 1279294 : Invalid Random per component behavior in spawn context (#107)

Author: PaulDemeulenaere

com.unity.visualeffectgraph/CHANGELOG.md

@@ -29,6 +29,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Fix exposed Texture2DArray and Cubemap types from shader graph not being taken into account in Output Mesh [Case 1265221](https://issuetracker.unity3d.com/product/unity/issues/guid/1265221/)
 - Allow world position usage in shaderGraph plugged into an alpha/opacity output [Case 1259511](https://issuetracker.unity3d.com/product/unity/issues/guid/1259511/)
 - GPU Evaluation of Construct Matrix
+- Random Per-Component on Set Attribute in Spawn Context [Case 1279294](https://issuetracker.unity3d.com/product/unity/issues/guid/1279294/)
 
 ## [10.0.0] - 2019-06-10
 ### Added

com.unity.visualeffectgraph/Editor/Models/Blocks/Implementations/Spawn/VFXSpawnerSetAttribute.cs

@@ -69,10 +69,10 @@ public override IEnumerable<VFXNamedExpression> parameters
                     {
                         default:
                         case RandomMode.PerComponent:
-                            random = new VFXExpressionCombine(Enumerable.Repeat(0, size).Select(_ => new VFXExpressionRandom(false, new RandId(this, 1))).ToArray());
+                            random = new VFXExpressionCombine(Enumerable.Range(0, size).Select(i => new VFXExpressionRandom(false, new RandId(this, i))).ToArray());
                             break;
                         case RandomMode.Uniform:
-                            random = new VFXExpressionCombine(Enumerable.Repeat(new VFXExpressionRandom(false, new RandId(this, 2)), size).ToArray());
+                            random = new VFXExpressionCombine(Enumerable.Repeat(new VFXExpressionRandom(false, new RandId(this, 0)), size).ToArray());
                             break;
                     }
                 }