Replace FLT_SMALL with FLT_EPSILON

ScriptableRenderPipeline/Core/ShaderLibrary/Common.hlsl

 #define HALF_PI     1.57079632679
 #define INV_HALF_PI 0.636619772367
 #define INFINITY    asfloat(0x7F800000)
-#define FLT_SMALL   0.0001
 #define LOG2_E      1.44269504089
 
 #define FLT_EPSILON 1.192092896e-07 // Smallest positive number, such that 1.0 + FLT_EPSILON != 1.0

ScriptableRenderPipeline/Core/ShaderLibrary/VolumeRendering.hlsl

 // Absorption coefficient from Disney: http://blog.selfshadow.com/publications/s2015-shading-course/burley/s2015_pbs_disney_bsdf_notes.pdf
 float3 TransmittanceColorAtDistanceToAbsorption(float3 transmittanceColor, float atDistance)
 {
-    return -log(transmittanceColor + 0.00001) / max(atDistance, 0.000001);
+    return -log(transmittanceColor + FLT_EPSILON) / max(atDistance, FLT_EPSILON);
 }
 
 

ScriptableRenderPipeline/HDRenderPipeline/Material/Lit/Lit.hlsl

         float NdotL = saturate(dot(bsdfData.coatNormalWS, L));
         float NdotV = preLightData.coatNdotV;
         float LdotV = dot(L, V);
-        float invLenLV = rsqrt(max(2 * LdotV + 2, FLT_SMALL));
+        float invLenLV = rsqrt(max(2 * LdotV + 2, FLT_EPSILON));
         float NdotH = saturate((NdotL + NdotV) * invLenLV);
         float LdotH = saturate(invLenLV * LdotV + invLenLV);
 
     float NdotL    = saturate(dot(bsdfData.normalWS, L)); // Must have the same value without the clamp
     float NdotV    = preLightData.NdotV;                  // Get the unaltered (geometric) version
     float LdotV    = dot(L, V);
-    float invLenLV = rsqrt(max(2 * LdotV + 2, FLT_SMALL)); // invLenLV = rcp(length(L + V)) - caution about the case where V and L are opposite, it can happen, use max to avoid this
+    float invLenLV = rsqrt(max(2 * LdotV + 2, FLT_EPSILON)); // invLenLV = rcp(length(L + V)) - caution about the case where V and L are opposite, it can happen, use max to avoid this
     float NdotH    = saturate((NdotL + NdotV) * invLenLV);
     float LdotH    = saturate(invLenLV * LdotV + invLenLV);