Rename to follow convention

ScriptableRenderPipeline/HDRenderPipeline/HDRP/HDStringConstants.cs

         public static readonly int _Result1 = Shader.PropertyToID("_Result1");
 
         public static readonly int _AmbientProbeCoeffs         = Shader.PropertyToID("_AmbientProbeCoeffs");
-        public static readonly int _Global_Extinction          = Shader.PropertyToID("_Global_Extinction");
-        public static readonly int _Global_Scattering          = Shader.PropertyToID("_Global_Scattering");
-        public static readonly int _Global_Asymmetry           = Shader.PropertyToID("_Global_Asymmetry");
+        public static readonly int _GlobalExtinction           = Shader.PropertyToID("_GlobalExtinction");
+        public static readonly int _GlobalScattering           = Shader.PropertyToID("_GlobalScattering");
+        public static readonly int _GlobalAsymmetry            = Shader.PropertyToID("_GlobalAsymmetry");
         public static readonly int _CornetteShanksConstant     = Shader.PropertyToID("_CornetteShanksConstant");
         public static readonly int _VBufferResolution          = Shader.PropertyToID("_VBufferResolution");
         public static readonly int _VBufferSliceCount          = Shader.PropertyToID("_VBufferSliceCount");

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Lighting/LightEvaluation.hlsl

 
 #if (SHADEROPTIONS_VOLUMETRIC_LIGHTING_PRESET != 0)
     float distVol = (lightData.lightType == GPULIGHTTYPE_PROJECTOR_BOX) ? distances.w : distances.x;
-    attenuation *= TransmittanceHomogeneousMedium(_Global_Extinction, distVol);
+    attenuation *= TransmittanceHomogeneousMedium(_GlobalExtinction, distVol);
 #endif
 
     // Projector lights always have cookies, so we can perform clipping inside the if().

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Lighting/Volumetrics/Resources/VolumetricLighting.compute

 CBUFFER_START(UnityVolumetricLighting)
     float4   _VBufferSampleOffset;              // {x, y, z}, w = rendered frame count
     float4x4 _VBufferCoordToViewDirWS;          // Actually just 3x3, but Unity can only set 4x4
-    float    _CornetteShanksConstant;           // CornetteShanksPhasePartConstant(_Global_Asymmetry)
+    float    _CornetteShanksConstant;           // CornetteShanksPhasePartConstant(_GlobalAsymmetry)
 CBUFFER_END
 
 //--------------------------------------------------------------------------------------------------
         // Sample the participating medium at 'tc' (or 'centerWS').
         // We consider it to be constant along the interval [t0, t1] (within the voxel).
         // TODO: piecewise linear.
-        float3 scattering = _Global_Scattering;
-        float  extinction = max(_Global_Extinction, FLT_MIN); // Avoid NaNs
-        float  asymmetry  = _Global_Asymmetry;
+        float3 scattering = _GlobalScattering;
+        float  extinction = max(_GlobalExtinction, FLT_MIN); // Avoid NaNs
+        float  asymmetry  = _GlobalAsymmetry;
         
         // TODO: define a function ComputeGlobalFogCoefficients(float3 centerWS),
         // which allows procedural definition of extinction and scattering.

ScriptableRenderPipeline/HDRenderPipeline/HDRP/Lighting/Volumetrics/VolumetricLighting.cs

                                                                             : VolumeProperties.GetNeutralVolumeProperties();
 
         float asymmetry = globalVolume != null ? globalVolume.volumeParameters.asymmetry : 0;
-        cmd.SetGlobalVector(HDShaderIDs._Global_Scattering, globalVolumeProperties.scattering);
-        cmd.SetGlobalFloat( HDShaderIDs._Global_Extinction, globalVolumeProperties.extinction);
-        cmd.SetGlobalFloat( HDShaderIDs._Global_Asymmetry,  asymmetry);
+        cmd.SetGlobalVector(HDShaderIDs._GlobalScattering, globalVolumeProperties.scattering);
+        cmd.SetGlobalFloat( HDShaderIDs._GlobalExtinction, globalVolumeProperties.extinction);
+        cmd.SetGlobalFloat( HDShaderIDs._GlobalAsymmetry,  asymmetry);
 
         int w = 0, h = 0, d = 0;
         ComputeVBufferResolutionAndScale(preset, (int)camera.screenSize.x, (int)camera.screenSize.y, ref w, ref h, ref d);

ScriptableRenderPipeline/HDRenderPipeline/HDRP/ShaderVariables.hlsl

     uint   _TaaFrameIndex;    // [0, 7]
     // Volumetric lighting.
     float4 _AmbientProbeCoeffs[7];      // 3 bands of SH, packed, rescaled and convolved with the phase function
-    float  _Global_Asymmetry;
-    float3 _Global_Scattering;
-    float  _Global_Extinction;
+    float  _GlobalAsymmetry;
+    float3 _GlobalScattering;
+    float  _GlobalExtinction;
     float4 _VBufferResolution;          // { w, h, 1/w, 1/h }
     float4 _VBufferSliceCount;          // { count, 1/count, 0, 0 }
     float4 _VBufferDepthEncodingParams; // See the call site for description