6 files changed, 36 insertions, 23 deletions
diff --git a/doc/classes/ARVRController.xml b/doc/classes/ARVRController.xml
index 47a9341643..2adc073ebe 100644
--- a/doc/classes/ARVRController.xml
+++ b/doc/classes/ARVRController.xml
@@ -62,7 +62,10 @@
 	</methods>
 	<members>
 		<member name="controller_id" type="int" setter="set_controller_id" getter="get_controller_id">
-			The controller's id. The first controller that the [ARVRServer] detects will have id 1, the second id 2, the third id 3, etc. When a controller is turned off, it's slot is freed. This ensures controllers will keep the same id even when controllers with lower ids are turned off.
+			The controller's id.
+			A controller id of 0 is unbound and will always result in an inactive node. Controller id 1 is reserved for the first controller that identifies itself as the left hand controller and id 2 is reserved for the first controller that identifies itself as the right hand controller.
+			For any other controller that the [ARVRServer] detects we continue with controller id 3.
+			When a controller is turned off, its slot is freed. This ensures controllers will keep the same id even when controllers with lower ids are turned off.
 		</member>
 		<member name="rumble" type="float" setter="set_rumble" getter="get_rumble">
 			The degree to which the tracker rumbles. Ranges from [code]0.0[/code] to [code]1.0[/code] with precision [code].01[/code]. If changed, updates [member ARVRPositionalTracker.rumble] accordingly.
diff --git a/doc/classes/ARVRServer.xml b/doc/classes/ARVRServer.xml
index 17202c8c2c..ffe6c35240 100644
--- a/doc/classes/ARVRServer.xml
+++ b/doc/classes/ARVRServer.xml
@@ -14,7 +14,7 @@
 		<method name="center_on_hmd">
 			<return type="void">
 			</return>
-			<argument index="0" name="ignore_tilt" type="bool">
+			<argument index="0" name="rotation_mode" type="bool">
 			</argument>
 			<argument index="1" name="keep_height" type="bool">
 			</argument>
@@ -154,5 +154,14 @@
 		<constant name="TRACKER_ANY" value="255" enum="TrackerType">
 			Used internally to select all trackers.
 		</constant>
+		<constant name="RESET_FULL_ROTATION" value="0" enum="RotationMode">
+			Fully reset the orientation of the HMD. Regardless of what direction the user is looking to in the real world. The user will look dead ahead in the virtual world.
+		</constant>
+		<constant name="RESET_BUT_KEEP_TILT" value="1" enum="RotationMode">
+			Resets the orientation but keeps the tilt of the device. So if we're looking down, we keep looking down but heading will be reset.
+		</constant>
+		<constant name="DONT_RESET_ROTATION" value="2" enum="RotationMode">
+			Does not reset the orientation of the HMD, only the position of the player gets centered.
+		</constant>
 	</constants>
 </class>
diff --git a/doc/classes/AnimationPlayer.xml b/doc/classes/AnimationPlayer.xml
index 570f5e9741..a244788020 100644
--- a/doc/classes/AnimationPlayer.xml
+++ b/doc/classes/AnimationPlayer.xml
@@ -133,6 +133,7 @@
 			<return type="float">
 			</return>
 			<description>
+				Returns the speed scaling ratio of the current animation channel. For instance, if this value is 1 then the animation plays at normal speed. If it's 0.5 then it plays at half speed. If it's 2 then it plays at double speed.
 			</description>
 		</method>
 		<method name="has_animation" qualifiers="const">
diff --git a/doc/classes/Mutex.xml b/doc/classes/Mutex.xml
index 4b845c05ad..74d59b2dd3 100644
--- a/doc/classes/Mutex.xml
+++ b/doc/classes/Mutex.xml
@@ -4,7 +4,7 @@
 		A synchronization Mutex.
 	</brief_description>
 	<description>
-		A synchronization Mutex. Element used in multi-threadding. Basically a binary [Semaphore]. Guarantees that only one thread has this lock, can be used to protect a critical section.
+		A synchronization Mutex. Element used to synchronize multiple [Thread]s. Basically a binary [Semaphore]. Guarantees that only one thread can ever acquire this lock at a time. Can be used to protect a critical section. Be careful to avoid deadlocks.
 	</description>
 	<tutorials>
 	</tutorials>
@@ -22,14 +22,14 @@
 			<return type="int" enum="Error">
 			</return>
 			<description>
-				Try locking this [code]Mutex[/code], does not block. Returns [OK] on success else [ERR_BUSY].
+				Try locking this [code]Mutex[/code], does not block. Returns [OK] on success, [ERR_BUSY] otherwise.
 			</description>
 		</method>
 		<method name="unlock">
 			<return type="void">
 			</return>
 			<description>
-				Unlock this [code]Mutex[/code], leaving it to others threads.
+				Unlock this [code]Mutex[/code], leaving it to other threads.
 			</description>
 		</method>
 	</methods>
diff --git a/doc/classes/Semaphore.xml b/doc/classes/Semaphore.xml
index d8deb9651a..c8206ff2c2 100644
--- a/doc/classes/Semaphore.xml
+++ b/doc/classes/Semaphore.xml
@@ -4,7 +4,7 @@
 		A synchronization Semaphore.
 	</brief_description>
 	<description>
-		A synchronization Semaphore. Element used in multi-threadding. Initialized to zero on creation.
+		A synchronization Semaphore. Element used to synchronize multiple [Thread]s. Initialized to zero on creation. Be careful to avoid deadlocks. For a binary version, see [Mutex].
 	</description>
 	<tutorials>
 	</tutorials>
@@ -15,14 +15,14 @@
 			<return type="int" enum="Error">
 			</return>
 			<description>
-				Lowers the [code]Semaphore[/code], allowing one more thread in.
+				Lowers the [code]Semaphore[/code], allowing one more thread in. Returns [OK] on success, [ERR_BUSY] otherwise.
 			</description>
 		</method>
 		<method name="wait">
 			<return type="int" enum="Error">
 			</return>
 			<description>
-				Tries to wait for the [code]Semaphore[/code], if its value is zero, blocks until non-zero.
+				Tries to wait for the [code]Semaphore[/code], if its value is zero, blocks until non-zero. Returns [OK] on success, [ERR_BUSY] otherwise.
 			</description>
 		</method>
 	</methods>
diff --git a/doc/classes/Transform2D.xml b/doc/classes/Transform2D.xml
index 17576f33ed..f4717aa995 100644
--- a/doc/classes/Transform2D.xml
+++ b/doc/classes/Transform2D.xml
@@ -4,7 +4,7 @@
 		2D Transformation. 3x2 matrix.
 	</brief_description>
 	<description>
-		Represents one or many transformations in 3D space such as translation, rotation, or scaling. It consists of a two [Vector2] x, y and [Vector2] "origin". It is similar to a 3x2 matrix.
+		Represents one or many transformations in 2D space such as translation, rotation, or scaling. It consists of a two [Vector2] x, y and [Vector2] "origin". It is similar to a 3x2 matrix.
 	</description>
 	<tutorials>
 	</tutorials>
@@ -17,7 +17,7 @@
 			<argument index="0" name="from" type="Transform">
 			</argument>
 			<description>
-				Constructs the [code]Transform2D[/code] from a 3D [Transform].
+				Constructs the transform from a 3D [Transform].
 			</description>
 		</method>
 		<method name="Transform2D">
@@ -30,7 +30,7 @@
 			<argument index="2" name="origin" type="Vector2">
 			</argument>
 			<description>
-				Constructs the [code]Transform2D[/code] from 3 [Vector2] consisting of rows x, y and origin.
+				Constructs the transform from 3 [Vector2]s representing x, y, and origin.
 			</description>
 		</method>
 		<method name="Transform2D">
@@ -41,7 +41,7 @@
 			<argument index="1" name="position" type="Vector2">
 			</argument>
 			<description>
-				Constructs the [code]Transform2D[/code] from rotation angle in radians and position [Vector2].
+				Constructs the transform from a given angle (in radians) and position.
 			</description>
 		</method>
 		<method name="affine_inverse">
@@ -57,7 +57,7 @@
 			<argument index="0" name="v" type="var">
 			</argument>
 			<description>
-				Transforms the given vector "v" by this transform basis (no translation).
+				Transforms the given vector by this transform's basis (no translation).
 			</description>
 		</method>
 		<method name="basis_xform_inv">
@@ -66,21 +66,21 @@
 			<argument index="0" name="v" type="var">
 			</argument>
 			<description>
-				Inverse-transforms the given vector "v" by this transform basis (no translation).
+				Inverse-transforms the given vector by this transform's basis (no translation).
 			</description>
 		</method>
 		<method name="get_origin">
 			<return type="Vector2">
 			</return>
 			<description>
-				Returns the origin [Vector2] (translation).
+				Returns the transform's origin (translation).
 			</description>
 		</method>
 		<method name="get_rotation">
 			<return type="float">
 			</return>
 			<description>
-				Returns the rotation (in radians).
+				Returns the transform's rotation (in radians).
 			</description>
 		</method>
 		<method name="get_scale">
@@ -98,7 +98,7 @@
 			<argument index="1" name="weight" type="float">
 			</argument>
 			<description>
-				Interpolates the transform to other Transform2D by weight amount (0-1).
+				Returns a transform interpolated between this transform and another by a given weight (0-1).
 			</description>
 		</method>
 		<method name="inverse">
@@ -121,7 +121,7 @@
 			<argument index="0" name="phi" type="float">
 			</argument>
 			<description>
-				Rotates the transform by phi.
+				Rotates the transform by the given angle (in radians).
 			</description>
 		</method>
 		<method name="scaled">
@@ -130,7 +130,7 @@
 			<argument index="0" name="scale" type="Vector2">
 			</argument>
 			<description>
-				Scales the transform by the specified 2D scaling factors.
+				Scales the transform by the given factor.
 			</description>
 		</method>
 		<method name="translated">
@@ -139,7 +139,7 @@
 			<argument index="0" name="offset" type="Vector2">
 			</argument>
 			<description>
-				Translates the transform by the specified offset.
+				Translates the transform by the given offset.
 			</description>
 		</method>
 		<method name="xform">
@@ -163,13 +163,13 @@
 	</methods>
 	<members>
 		<member name="origin" type="Vector2" setter="" getter="">
-			The translation offset of the transform.
+			The transform's translation offset.
 		</member>
 		<member name="x" type="Vector2" setter="" getter="">
-			The X axis of 2x2 basis matrix containing 2 [Vector2] as its columns: X axis and Y axis. These vectors can be interpreted as the basis vectors of local coordinate system traveling with the object.
+			The X axis of 2x2 basis matrix containing 2 [Vector2]s as its columns: X axis and Y axis. These vectors can be interpreted as the basis vectors of local coordinate system traveling with the object.
 		</member>
 		<member name="y" type="Vector2" setter="" getter="">
-			The Y axis of 2x2 basis matrix containing 2 [Vector2] as its columns: X axis and Y axis. These vectors can be interpreted as the basis vectors of local coordinate system traveling with the object.
+			The Y axis of 2x2 basis matrix containing 2 [Vector2]s as its columns: X axis and Y axis. These vectors can be interpreted as the basis vectors of local coordinate system traveling with the object.
 		</member>
 	</members>
 	<constants>