Fix Case 1223747 - NaN caused by normal bending (#181)

* Update Pass.template

* Update CHANGELOG.md

Author: ludovic-theobald

com.unity.visualeffectgraph/CHANGELOG.md

@@ -18,6 +18,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Unexpected exception while trying to display capacity warning [Case 1294180](https://issuetracker.unity3d.com/product/unity/issues/guid/1294180/)
 - Exclude Operator, Context, Block and Subgraph from Preset [Case 1232309](https://issuetracker.unity3d.com/product/unity/issues/guid/1232309/)
 - Fix [Case 1212002](https://fogbugz.unity3d.com/f/cases/1212002/)
+- Fix [Case 1223747](https://fogbugz.unity3d.com/f/cases/1223747/)
 
 ## [10.2.0] - 2020-10-19
 ### Added

com.unity.visualeffectgraph/Shaders/ParticlePlanarPrimitives/Pass.template

@@ -24,7 +24,7 @@ float3 tangentWS = i.VFX_VARYING_TANGENT;
 float3 bitangentWS = cross(i.VFX_VARYING_TANGENT,i.VFX_VARYING_NORMAL);
 
 #if defined(VFX_VARYING_BENTFACTORS) && USE_NORMAL_BENDING	
-float3 bentFactors = float3(i.VFX_VARYING_BENTFACTORS.xy,sqrt(1.0f - dot(i.VFX_VARYING_BENTFACTORS,i.VFX_VARYING_BENTFACTORS)));
+float3 bentFactors = float3(i.VFX_VARYING_BENTFACTORS.xy,sqrt(max(0.0f,1.0f - dot(i.VFX_VARYING_BENTFACTORS,i.VFX_VARYING_BENTFACTORS))));
 normalWS = tangentWS * bentFactors.x + bitangentWS * bentFactors.y + normalWS * bentFactors.z;
 tangentWS = normalize(cross(normalWS,bitangentWS));
 bitangentWS = cross(tangentWS,normalWS);