Avoid the warning about division by 0

ScriptableRenderPipeline/HDRenderPipeline/ShaderPass/FragInputs.hlsl

     bool isFrontFace;
 };
 
-// FragInputs use dir vector that are normalized in the code even if not used
-// so we initialize them to a valid != 0 to shutdown compiler warning
-FragInputs InitializeFragInputs()
-{
-    FragInputs output;
-    ZERO_INITIALIZE(FragInputs, output);
-
-    // Init to some default value to make the computer quiet (else it output "divide by zero" warning even if value is not used).
-    output.worldToTangent[0] = float3(1, 0, 0);
-    output.worldToTangent[1] = float3(0, 1, 0);
-    output.worldToTangent[2] = float3(0, 0, 1);
-
-    return output;
-}
-
 void GetVaryingsDataDebug(uint paramId, FragInputs input, inout float3 result, inout bool needLinearToSRGB)
 {
     switch (paramId)

ScriptableRenderPipeline/HDRenderPipeline/ShaderPass/ShaderPassDepthOnly.hlsl

     // input.positionSS is SV_Position
     PositionInputs posInput = GetPositionInput(input.positionSS.xy, _ScreenSize.zw);
     UpdatePositionInput(input.positionSS.z, input.positionSS.w, input.positionWS, posInput);
+
+#ifdef VARYINGS_NEED_POSITION_WS
+#else
+    float3 V = 0; // Avoid the division by 0
+#endif
 
     SurfaceData surfaceData;
     BuiltinData builtinData;

ScriptableRenderPipeline/HDRenderPipeline/ShaderPass/ShaderPassDistortion.hlsl

     // input.positionSS is SV_Position
     PositionInputs posInput = GetPositionInput(input.positionSS.xy, _ScreenSize.zw);
     UpdatePositionInput(input.positionSS.z, input.positionSS.w, input.positionWS, posInput);
+
+#ifdef VARYINGS_NEED_POSITION_WS
+#else
+    float3 V = 0; // Avoid the division by 0
+#endif
 
     // Perform alpha testing + get distortion
     SurfaceData surfaceData;

ScriptableRenderPipeline/HDRenderPipeline/ShaderPass/ShaderPassForward.hlsl

     // input.positionSS is SV_Position
     PositionInputs posInput = GetPositionInput(input.positionSS.xy, _ScreenSize.zw, uint2(input.positionSS.xy) / GetTileSize());
     UpdatePositionInput(input.positionSS.z, input.positionSS.w, input.positionWS, posInput);
+
+#ifdef VARYINGS_NEED_POSITION_WS
+#else
+    float3 V = 0; // Avoid the division by 0
+#endif
 
     SurfaceData surfaceData;
     BuiltinData builtinData;

ScriptableRenderPipeline/HDRenderPipeline/ShaderPass/ShaderPassForwardUnlit.hlsl

     // input.positionSS is SV_Position
     PositionInputs posInput = GetPositionInput(input.positionSS.xy, _ScreenSize.zw);
     UpdatePositionInput(input.positionSS.z, input.positionSS.w, input.positionWS, posInput);
+
+#ifdef VARYINGS_NEED_POSITION_WS
+#else
+    float3 V = 0; // Avoid the division by 0
+#endif
 
     SurfaceData surfaceData;
     BuiltinData builtinData;

ScriptableRenderPipeline/HDRenderPipeline/ShaderPass/ShaderPassGBuffer.hlsl

     // input.positionSS is SV_Position
     PositionInputs posInput = GetPositionInput(input.positionSS.xy, _ScreenSize.zw);
     UpdatePositionInput(input.positionSS.z, input.positionSS.w, input.positionWS, posInput);
+
+#ifdef VARYINGS_NEED_POSITION_WS
+#else
+    float3 V = 0; // Avoid the division by 0
+#endif
 
     SurfaceData surfaceData;
     BuiltinData builtinData;

ScriptableRenderPipeline/HDRenderPipeline/ShaderPass/ShaderPassLightTransport.hlsl

     // input.positionSS is SV_Position
     PositionInputs posInput = GetPositionInput(input.positionSS.xy, _ScreenSize.zw);
     UpdatePositionInput(input.positionSS.z, input.positionSS.w, input.positionWS, posInput);
-    // No position and depth in case of light transport
-    float3 V = float3(0.0, 0.0, 1.0); // No vector view in case of light transport
+
+#ifdef VARYINGS_NEED_POSITION_WS
+    float3 V = GetWorldSpaceNormalizeViewDir(input.positionWS);
+#else
+    float3 V = 0; // Avoid the division by 0
+#endif
 
     SurfaceData surfaceData;
     BuiltinData builtinData;

ScriptableRenderPipeline/HDRenderPipeline/ShaderPass/ShaderPassVelocity.hlsl

     // input.positionSS is SV_Position
     PositionInputs posInput = GetPositionInput(input.positionSS.xy, _ScreenSize.zw);
     UpdatePositionInput(input.positionSS.z, input.positionSS.w, input.positionWS, posInput);
+
+#ifdef VARYINGS_NEED_POSITION_WS
+#else
+    float3 V = 0; // Avoid the division by 0
+#endif
 
     // Perform alpha testing + get velocity
     SurfaceData surfaceData;

ScriptableRenderPipeline/HDRenderPipeline/ShaderPass/VaryingMesh.hlsl

 
 FragInputs UnpackVaryingsMeshToFragInputs(PackedVaryingsMeshToPS input)
 {
-    FragInputs output = InitializeFragInputs();
+    FragInputs output;
+    ZERO_INITIALIZE(FragInputs, output);
+
+    // Init to some default value to make the computer quiet (else it output "divide by zero" warning even if value is not used).
+    // TODO: this is a really poor workaround, but the variable is used in a bunch of places
+    // to compute normals which are then passed on elsewhere to compute other values...
+    output.worldToTangent = k_identity3x3;
 
     output.positionSS = input.positionCS; // input.positionCS is SV_Position