Removed "Use Density Mode" checkbox. Shader feature is now automatically deduced from the parameters of all layers.

Assets/ScriptableRenderPipeline/HDRenderPipeline/Material/InfluenceLayeredLit/Editor/InfluenceLayeredLitUI.cs

             public readonly GUIContent layeringOptionText = new GUIContent("Layering Options");
 
             public readonly GUIContent useHeightBasedBlendText = new GUIContent("Use Height Based Blend", "Layer will be blended with the underlying layer based on the height.");
-            public readonly GUIContent useDensityModeModeText = new GUIContent("Use Density Mode", "Enable density mode");
             public readonly GUIContent useMainLayerInfluenceModeText = new GUIContent("Main Layer Influence", "Switch between regular layers mode and base/layers mode");
 
             public readonly GUIContent opacityAsDensityText = new GUIContent("Use Opacity as Density", "Use Opacity as Density.");
         const string kUseHeightBasedBlend = "_UseHeightBasedBlend";
 
         // Density/opacity mode
-        MaterialProperty useDensityMode = null;
-        const string kUseDensityMode = "_UseDensityMode";
         MaterialProperty[] opacityAsDensity = new MaterialProperty[kMaxLayerCount];
         const string kOpacityAsDensity = "_OpacityAsDensity";
 
             useMainLayerInfluence = FindProperty(kkUseMainLayerInfluence, props);
             useHeightBasedBlend = FindProperty(kUseHeightBasedBlend, props);
             heightTransition = FindProperty(kHeightTransition, props);
-
-            useDensityMode = FindProperty(kUseDensityMode, props);
 
             for (int i = 0; i < kMaxLayerCount; ++i)
             {
                 {
                     int paramIndex = layerIndex - 1;
 
-                    bool useDensityModeEnable = useDensityMode.floatValue != 0.0f;
-                    if (useDensityModeEnable)
-                    {
-                        m_MaterialEditor.ShaderProperty(opacityAsDensity[layerIndex], styles.opacityAsDensityText);
-                    }
+                    m_MaterialEditor.ShaderProperty(opacityAsDensity[layerIndex], styles.opacityAsDensityText);
 
                     if (mainLayerInfluenceEnable)
                     {
             }
 
             EditorGUI.BeginChangeCheck();
-            EditorGUI.showMixedValue = useDensityMode.hasMixedValue;
-            bool useDensityModeEnable = EditorGUILayout.Toggle(styles.useDensityModeModeText, useDensityMode.floatValue > 0.0f);
-            if (EditorGUI.EndChangeCheck())
-            {
-                useDensityMode.floatValue = useDensityModeEnable ? 1.0f : 0.0f;
-            }
-
-            EditorGUI.BeginChangeCheck();
             EditorGUI.showMixedValue = useHeightBasedBlend.hasMixedValue;
             bool enabled = EditorGUILayout.Toggle(styles.useHeightBasedBlendText, useHeightBasedBlend.floatValue > 0.0f);
             if (EditorGUI.EndChangeCheck())
             bool useHeightBasedBlend = material.GetFloat(kUseHeightBasedBlend) != 0.0f;
             SetKeyword(material, "_HEIGHT_BASED_BLEND", useHeightBasedBlend);
 
-            bool useDensityModeEnable = material.GetFloat(kUseDensityMode) != 0.0f;
+            bool useDensityModeEnable = false;
+            for (int i = 0; i < material.GetInt(kLayerCount); ++i )
+            {
+                useDensityModeEnable |= material.GetFloat(kOpacityAsDensity + i) != 0.0f;
+            }
             SetKeyword(material, "_DENSITY_MODE", useDensityModeEnable);
         }