manual/render/shader_nodes/shader/ray_portal.rst

@@ -14,14 +14,15 @@ It acts much like a :doc:`Transparent BSDF </render/shader_nodes/shader/transpar
 render passes are passed through,
 and it is affected by light path max transparent bounces.
 
-
 .. note::
 
-   - The portal only allows rays to pass through in one direction.
+   - The Ray Portal BSDF only allows rays to pass through it in one direction. Add a
+     second portal at the target location to make rays go in the other direction as well.
+
+   - Light sampling does not work efficiently through portals. This can lead to increased
+     noised from lights on the other side of portals. Particularly small lights may be very
+     noisy, or not pass through at all.
 
-   - Some of the techniques Cycles uses to reduce noise does not work through portals.
-     This leads to issues like increased noise from lights passing through portals,
-     or if the light is small, it's light may not pass through the portal.
 
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