Updated PLU description and HDRP Asset for terrain holes (#5211)

JordanL8 · sebastienlagarde · commit 5ddff5caa025 · 2019-12-11T00:05:05.000+01:00
* Updated PLU description and HDRP Asset for terrain holes

* Update Physical-Light-Units.md
diff --git a/com.unity.render-pipelines.high-definition/Documentation~/HDRP-Asset.md b/com.unity.render-pipelines.high-definition/Documentation~/HDRP-Asset.md
@@ -41,11 +41,12 @@ When you create an HDRP Asset, open it in the Inspector to edit its properties.
 | **Motion Vectors**                      | Enable the checkbox to make HDRP support motion vectors. HDRP uses motion vectors for effects like screen space reflection (SSR) and motion blur. When disabled, motion blur has no effect and HDRP calculates SSR with lower quality. |
 | **Runtime Debug Display**               | Enable the checkbox to make HDRP display Material and Lighting properties at runtime to help debugging.Disable this checkbox to reduce build time and Shader memory. This disables the following debug modes: All Material debug modes except GBuffer debug. The Lux meter, diffuse lighting only, and specular lighting only debug modes. The overriding option for overriding albedo. |
 | **Dithering Cross-fade**                | Enable the checkbox to make HDRP support dithering cross fade. This allows HDRP to implement smooth transitions between a GameObject’s LOD levels. When disabled, this reduces build time if you are not using LOD fade. |
+| **Terrain Hole**                        | Enable the checkbox to make HDRP support [Terrain Holes](https://docs.unity3d.com/2019.3/Documentation/Manual/terrain-PaintHoles.html). If you do not enable this, Terrain Holes are not visible in your Scene. |
 | **Transparent Backface**                | Enable the checkbox to make HDRP support transparent back-face render passes. If your Unity Project does not need to make a transparent back-face pass, disable this checkbox to reduce build time. |
 | **Transparent Depth Prepass**           | Enable the checkbox to make HDRP support transparent depth render prepasses. If your Unity Project does not need to make a transparent depth prepass, disable this checkbox to reduce build time . |
 | **Transparent Depth Postpass**          | Enable the checkbox to make HDRP support transparent depth render postpasses. If your Unity Project does not make use of a transparent depth postpass. Uncheck this checkbox to reduce build time . |
 | **Custom Pass**                         | Enable the checkbox to make HDRP support custom passes. If your Unity Project does not make use [Custom Passes](Custom-Pass.html), Uncheck this checkbox to save memory . |
-| - **Custom Buffer Format**                | Specify the texture format for the custom buffer. If you experience banding issues due to your custom passes, you can change it to either `R11G11B10` if you don't need alpha or `R16G16B16A16`. |
+| - **Custom Buffer Format**              | Specify the texture format for the custom buffer. If you experience banding issues due to your custom passes, you can change it to either `R11G11B10` if you don't need alpha or `R16G16B16A16`. |
 | **Realtime Raytracing (Preview)**       | Enable the checkbox to enable HDRP realtime ray tracing (Experimental). It requires to have ray tracing compatible hardware. For more information, please refer to the [Ray Tracing Getting Started](Ray-Tracing-Getting-Started.html#HardwareRequirements) page. |
 | **Raytracing Tier**                     | Select the active tier for ray tracing effects. For more information, please refer to the [Ray Tracing Tier Table](Ray-Tracing-Getting-Started.html#TierTable). |
 | - **LOD Bias**                          | Set the value that Cameras use to calculate their LOD bias. The Camera uses this value differently depending on the **LOD Bias Mode** you select. |
diff --git a/com.unity.render-pipelines.high-definition/Documentation~/Physical-Light-Units.md b/com.unity.render-pipelines.high-definition/Documentation~/Physical-Light-Units.md
@@ -14,7 +14,9 @@ The base unit of [luminous intensity](Glossary.html#LuminousIntensity) in the In
 
 #### Lumen:
 
-The unit of [luminous flux](Glossary.html#LuminousFlux). Measures the total quantity of visible light a source emits. A light source emitting 1 [candela](#Candela) of luminous intensity from an area of 1 steradian has a luminous flux of 1 lumen.
+The unit of [luminous flux](Glossary.html#LuminousFlux). Describes the total amount of visible light that a light source emits in all directions. When you use this unit, the amount of visible light is independent of the source's size meaning the illumination level of a Scene does not change depending on the size of a light source. However, highlights that a light source produces dim as the area of the light source increases. This is because the same power is spread across a larger area.
+
+A light source that emits 1 [candela](#Candela) of [luminous intensity](Glossary.html#LuminousIntensity) from an area of 1 steradian has a luminous flux of 1 lumen.
 
 <a name="Lux"></a>
 
@@ -26,7 +28,9 @@ The unit of [illuminance](Glossary.html#Illuminance). A light source that emits
 
 #### Nits (candela per square meter):
 
-Measures the apparent brightness of light either emitted from a light source, or reflected off a surface, to the human eye. A light source that emits 1 candela of [luminous intensity](Glossary.html#LuminousIntensity) onto an area of 1 square meter has a luminance of 1 candela per square meter.
+The unit of luminance. Describes the surface power of a visible light source. When you use this unit, the overall power of a light source depends the size of the light source, meaning the the illumination level of a Scene changes depending on the size of the light source.  Highlights that a light source produces conserve their intensity regardless of the size of the surface.
+
+A light source that emits 1 candela of [luminous intensity](Glossary.html#LuminousIntensity) onto an area of 1 square meter has a luminance of 1 candela per square meter.
 
 <a name="EV"></a>
 
