diff --git a/doc/classes/PhysicsMaterial.xml b/doc/classes/PhysicsMaterial.xml
index 64106264968..0889c238dc1 100644
--- a/doc/classes/PhysicsMaterial.xml
+++ b/doc/classes/PhysicsMaterial.xml
@@ -12,6 +12,7 @@
 	</methods>
 	<members>
 		<member name="absorbent" type="bool" setter="set_absorbent" getter="is_absorbent" default="false">
+			If [code]true[/code], subtracts the bounciness from the colliding object's bounciness instead of adding it.
 		</member>
 		<member name="bounce" type="float" setter="set_bounce" getter="get_bounce" default="0.0">
 			The body's bounciness. Values range from [code]0[/code] (no bounce) to [code]1[/code] (full bounciness).
@@ -20,6 +21,7 @@
 			The body's friction. Values range from [code]0[/code] (frictionless) to [code]1[/code] (maximum friction).
 		</member>
 		<member name="rough" type="bool" setter="set_rough" getter="is_rough" default="false">
+			If [code]true[/code], the physics engine will use the friction of the object marked as "rough" when two objects collide. If [code]false[/code], the physics engine will use the lowest friction of all colliding objects instead. If [code]true[/code] for both colliding objects, the physics engine will use the highest friction.
 		</member>
 	</members>
 	<constants>