Use Gizmo6FacesBox in PlanarReflectionProbe

com.unity.render-pipelines.high-definition/HDRP/Editor/Lighting/Reflection/Volume/InfluenceVolumeUI.Gizmos.cs

 using System;
 using UnityEngine;
 using UnityEngine.Experimental.Rendering.HDPipeline;
+using UnityEngine.Experimental.Gizmo;
 
 namespace UnityEditor.Experimental.Rendering.HDPipeline
 {
                     d.boxInfluenceOffset, d.boxInfluenceSizeOffset,
                     d.sphereInfluenceRadiusOffset,
                     (editedHandle & HandleType.Influence) != 0,
-                    k_GizmoThemeColorInfluence);
+                    k_GizmoThemeColorInfluence,
+                    false);
 
             if ((showedHandle & HandleType.InfluenceNormal) != 0)
                 DrawGizmos_FadeHandle(
                     (editedHandle & HandleType.InfluenceNormal) != 0,
-                    k_GizmoThemeColorInfluenceNormal);
+                    k_GizmoThemeColorInfluenceNormal,
+                    true);
         }
 
         static void DrawGizmos_BaseHandle(
             {
                 case ShapeType.Box:
                 {
-                    if (isSolid)
-                        Gizmos.DrawCube(d.boxBaseOffset, d.boxBaseSize);
-                    else
-                        Gizmos.DrawWireCube(d.boxBaseOffset, d.boxBaseSize);
+                    s.boxBaseHandle.center = d.boxBaseOffset;
+                    s.boxBaseHandle.size = d.boxBaseSize;
+                    s.boxBaseHandle.DrawHull(isSolid);
                     break;
                 }
                 case ShapeType.Sphere:
             InfluenceVolumeUI s, InfluenceVolume d, Matrix4x4 matrix,
             Vector3 boxOffset, Vector3 boxSizeOffset,
             float sphereOffset,
-            bool isSolid, Color color)
+            bool isSolid, Color color, bool isNormal)
         {
             var mat = Gizmos.matrix;
             var c = Gizmos.color;
             {
                 case ShapeType.Box:
                 {
-                    if (isSolid)
-                        Gizmos.DrawCube(d.boxBaseOffset + boxOffset, d.boxBaseSize + boxSizeOffset);
-                    else
-                        Gizmos.DrawWireCube(d.boxBaseOffset + boxOffset, d.boxBaseSize + boxSizeOffset);
+                    Gizmo6FacesBox refBox = isNormal ? s.boxInfluenceNormalHandle : s.boxInfluenceHandle;
+                    refBox.center = d.boxBaseOffset + boxOffset;
+                    refBox.size = d.boxBaseSize + boxSizeOffset;
+                    refBox.DrawHull(isSolid);
                     break;
                 }
                 case ShapeType.Sphere:

com.unity.render-pipelines.high-definition/HDRP/Editor/Lighting/Reflection/Volume/InfluenceVolumeUI.Handles.cs

 using UnityEngine;
 using UnityEngine.Experimental.Rendering.HDPipeline;
 using Object = UnityEngine.Object;
+using UnityEngine.Experimental.Gizmo;
 
 namespace UnityEditor.Experimental.Rendering.HDPipeline
 {
 
         static void DrawBoxHandle(
             InfluenceVolumeUI s, InfluenceVolume d, Editor o, Object sourceAsset,
-            Func<InfluenceVolumeUI, BoxBoundsHandle> boundsGetter,
+            Func<InfluenceVolumeUI, Gizmo6FacesBox> boundsGetter,
             ref Vector3 center, ref Vector3 size)
         {
             var b = boundsGetter(s);
 
         static void DrawBoxFadeHandle(
             InfluenceVolumeUI s, InfluenceVolume d, Editor o, Object sourceAsset,
-            Func<InfluenceVolumeUI, BoxBoundsHandle> boundsGetter,
+            Func<InfluenceVolumeUI, Gizmo6FacesBox> boundsGetter,
             Vector3 baseOffset, Vector3 baseSize,
             ref Vector3 positive, ref Vector3 negative)
         {

com.unity.render-pipelines.high-definition/HDRP/Editor/Lighting/Reflection/Volume/InfluenceVolumeUI.cs

 using UnityEditor.IMGUI.Controls;
 using UnityEngine;
 using UnityEngine.Experimental.Rendering.HDPipeline;
+using UnityEngine.Experimental.Gizmo;
 
 namespace UnityEditor.Experimental.Rendering.HDPipeline
 {
 
         static readonly int k_ShapeCount = Enum.GetValues(typeof(ShapeType)).Length;
 
-        public BoxBoundsHandle boxBaseHandle = new BoxBoundsHandle();
-        public BoxBoundsHandle boxInfluenceHandle = new BoxBoundsHandle();
-        public BoxBoundsHandle boxInfluenceNormalHandle = new BoxBoundsHandle();
+        public Gizmo6FacesBox boxBaseHandle;
+        public Gizmo6FacesBoxContained boxInfluenceHandle;
+        public Gizmo6FacesBoxContained boxInfluenceNormalHandle;
 
         public SphereBoundsHandle sphereBaseHandle = new SphereBoundsHandle();
         public SphereBoundsHandle sphereInfluenceHandle = new SphereBoundsHandle();
             : base(k_ShapeCount + k_AnimBoolFields)
         {
             isSectionAdvancedInfluenceSettings.value = false;
+
+            boxBaseHandle = new Gizmo6FacesBox(monochromeFace:true, monochromeSelectedFace:true);
+            boxInfluenceHandle = new Gizmo6FacesBoxContained(boxBaseHandle, monochromeFace:true, monochromeSelectedFace:true);
+            boxInfluenceNormalHandle = new Gizmo6FacesBoxContained(boxBaseHandle, monochromeFace:true, monochromeSelectedFace:true);
+
+            Color[] handleColors = new Color[]
+            {
+                HDReflectionProbeEditor.k_handlesColor[0][0],
+                HDReflectionProbeEditor.k_handlesColor[0][1],
+                HDReflectionProbeEditor.k_handlesColor[0][2],
+                HDReflectionProbeEditor.k_handlesColor[1][0],
+                HDReflectionProbeEditor.k_handlesColor[1][1],
+                HDReflectionProbeEditor.k_handlesColor[1][2]
+            };
+            boxBaseHandle.handleColors = handleColors;
+            boxInfluenceHandle.handleColors = handleColors;
+            boxInfluenceNormalHandle.handleColors = handleColors;
+
+            boxBaseHandle.faceColors = new Color[] { HDReflectionProbeEditor.k_GizmoThemeColorExtent };
+            boxBaseHandle.faceColorsSelected = new Color[] { HDReflectionProbeEditor.k_GizmoThemeColorExtentFace };
+            boxInfluenceHandle.faceColors = new Color[] { HDReflectionProbeEditor.k_GizmoThemeColorInfluenceBlend };
+            boxInfluenceHandle.faceColorsSelected = new Color[] { HDReflectionProbeEditor.k_GizmoThemeColorInfluenceBlendFace };
+            boxInfluenceNormalHandle.faceColors = new Color[] { HDReflectionProbeEditor.k_GizmoThemeColorInfluenceNormalBlend };
+            boxInfluenceNormalHandle.faceColorsSelected = new Color[] { HDReflectionProbeEditor.k_GizmoThemeColorInfluenceNormalBlendFace };
         }
 
         public override void Update()