Hdrp/docs/fix 1305538 (#3112)

* Added information about using recursive rendering and other effects

* Fixed formatting

Author: JordanL8

com.unity.render-pipelines.high-definition/Documentation~/Ray-Traced-Shadows.md

@@ -131,5 +131,11 @@ Ray-traced shadows offer an alternative to the [exponential variance shadow map]
 | - **Denoiser Radius** | Controls the radius of the spatio-temporal filter.           |
 
 
-## Notes
-Ray-traced shadows do not support the **Two Sided** option for the Mesh Renderer's **Cast Shadows** property. To use double-sided shadows for a mesh, open the Mesh Renderer's Material in the Inspector and, in the **Surface Options** section, enable the **Double-Sided** property.
+## Limitations
+
+#### Double-sided shadows
+Ray-traced shadows do not support the **Two Sided** option for the Mesh Renderer's **Cast Shadows** property. To use double-sided shadows for a mesh, open the Mesh Renderer's Material in the Inspector and, in the **Surface Options** section, enable the **Double-Sided** property.
+
+#### Recursive rendering
+
+GameObjects HDRP renders using [recursive rendering](Ray-Tracing-Recursive-Rendering.md) cannot receive ray-traced shadows. If you enable both effects, HDRP renders rasterized [shadows](Shadows-in-HDRP.md) on recursively rendered GameObjects.

com.unity.render-pipelines.high-definition/Documentation~/Ray-Tracing-Recursive-Rendering.md

@@ -27,6 +27,10 @@ You can also do this for Shader Graph master nodes:
 1. In the Project window, double-click on the Shader to open it in Shader Graph.
 2. In the **Graph Settings** tab of the **Graph Inspector**, go to **Surface Options** and enable **Recursive Rendering (Preview)**.
 
+It is best practice to use recursive rendering in situations that require multi-bounced reflection and refraction, for example car headlights. Although recursive rendering also produces ray-traced reflections in more simple scenarios, like for a mirror or a puddle, it is best practice to use [ray-traced reflections](Ray-Traced-Reflections.md) here for performance reasons.
+
+Since recursive rendering uses an independent render pass, HDRP cannot render any other ray-traced effects on recursively rendered GameObjects. For example, it cannot render effects such as ray-traced subsurface scattering or ray-traced shadows.
+
 ## Properties
 
 | Property       | Description                                                  |