[HDRP] Adding missing camera toolips (#4207)

* Missing camera tooltips

Culling mask and occlusion culling

* Changelog

Co-authored-by: sebastienlagarde <[email protected]>

Author: remi-chapelain

com.unity.render-pipelines.high-definition/Editor/RenderPipeline/Camera/HDCameraUI.Rendering.Skin.cs

@@ -14,8 +14,8 @@ class Styles
 
                 public static readonly GUIContent dithering = EditorGUIUtility.TrTextContent("Dithering", "Should we apply 8-bit dithering to the final render?");
                 public static readonly GUIContent stopNaNs = EditorGUIUtility.TrTextContent("Stop NaNs", "Automatically replaces NaN/Inf in shaders by a black pixel to avoid breaking some effects. This will slightly affect performances and should only be used if you experience NaN issues that you can't fix.");
-                public static readonly GUIContent cullingMask = EditorGUIUtility.TrTextContent("Culling Mask");
-                public static readonly GUIContent occlusionCulling = EditorGUIUtility.TrTextContent("Occlusion Culling");
+                public static readonly GUIContent cullingMask = EditorGUIUtility.TrTextContent("Culling Mask", "Specifies the list of layers the camera should render.");
+                public static readonly GUIContent occlusionCulling = EditorGUIUtility.TrTextContent("Occlusion Culling", "When enabled, the camera does not render objects that are being obscured by other geometry.");
 
                 public static readonly GUIContent SMAAQualityPresetContent = EditorGUIUtility.TrTextContent("Quality Preset", "The quality preset for SMAA, low has the best performance but worst quality, High has the highest quality but worst performance.");