Improve the PrimitiveMesh-derived class documentations

(cherry picked from commit 30474b82158af40057febb689a860f04d207f4cb)

doc/classes/CubeMesh.xml

@@ -5,6 +5,7 @@
 	</brief_description>
 	<description>
 		Generate an axis-aligned cuboid [PrimitiveMesh].
+		The cube's UV layout is arranged in a 3×2 layout that allows texturing each face individually. To apply the same texture on all faces, change the material's UV property to [code]Vector3(3, 2, 1)[/code].
 	</description>
 	<tutorials>
 	</tutorials>

doc/classes/CylinderMesh.xml

@@ -4,7 +4,7 @@
 		Class representing a cylindrical [PrimitiveMesh].
 	</brief_description>
 	<description>
-		Class representing a cylindrical [PrimitiveMesh].
+		Class representing a cylindrical [PrimitiveMesh]. This class can be used to create cones by setting either the [member top_radius] or [member bottom_radius] properties to 0.0.
 	</description>
 	<tutorials>
 	</tutorials>

doc/classes/PlaneMesh.xml

@@ -4,7 +4,7 @@
 		Class representing a planar [PrimitiveMesh].
 	</brief_description>
 	<description>
-		Class representing a planar [PrimitiveMesh]. This flat mesh does not have a thickness.
+		Class representing a planar [PrimitiveMesh]. This flat mesh does not have a thickness. By default, this mesh is aligned on the X and Z axes; this default rotation isn't suited for use with billboarded materials. For billboarded materials, use [QuadMesh] instead.
 	</description>
 	<tutorials>
 	</tutorials>
@@ -15,10 +15,10 @@
 			Size of the generated plane. Defaults to (2.0, 2.0).
 		</member>
 		<member name="subdivide_depth" type="int" setter="set_subdivide_depth" getter="get_subdivide_depth">
-			Number of subdivision along the z-axis. Defaults to 0.
+			Number of subdivision along the Z axis. Defaults to 0.
 		</member>
 		<member name="subdivide_width" type="int" setter="set_subdivide_width" getter="get_subdivide_width">
-			Number of subdivision along the x-axis. Defaults to 0.
+			Number of subdivision along the X axis. Defaults to 0.
 		</member>
 	</members>
 	<constants>

doc/classes/PrismMesh.xml

@@ -12,19 +12,19 @@
 	</methods>
 	<members>
 		<member name="left_to_right" type="float" setter="set_left_to_right" getter="get_left_to_right">
-			Displacement of the upper edge along the x-axis. 0.0 positions edge straight above the bottome left edge. Defaults to 0.5 (positioned on the midpoint).
+			Displacement of the upper edge along the X axis. 0.0 positions edge straight above the bottom-left edge. Defaults to 0.5 (positioned on the midpoint).
 		</member>
 		<member name="size" type="Vector3" setter="set_size" getter="get_size">
 			Size of the prism. Defaults to (2.0, 2.0, 2.0).
 		</member>
 		<member name="subdivide_depth" type="int" setter="set_subdivide_depth" getter="get_subdivide_depth">
-			Number of added edge loops along the z-axis. Defaults to 0.
+			Number of added edge loops along the Z axis. Defaults to 0.
 		</member>
 		<member name="subdivide_height" type="int" setter="set_subdivide_height" getter="get_subdivide_height">
-			Number of added edge loops along the y-axis. Defaults to 0.
+			Number of added edge loops along the Y axis. Defaults to 0.
 		</member>
 		<member name="subdivide_width" type="int" setter="set_subdivide_width" getter="get_subdivide_width">
-			Number of added edge loops along the x-axis. Defaults to 0.
+			Number of added edge loops along the X axis. Defaults to 0.
 		</member>
 	</members>
 	<constants>

doc/classes/QuadMesh.xml

@@ -4,7 +4,7 @@
 		Class representing a square mesh.
 	</brief_description>
 	<description>
-		Class representing a square mesh with size (2,2,0). Consider using a [PlaneMesh] if you require a differently sized plane.
+		Class representing a square [PrimitiveMesh]. This flat mesh does not have a thickness. By default, this mesh is aligned on the X and Y axes; this default rotation is more suited for use with billboarded materials. Unlike [PlaneMesh], this mesh doesn't provide subdivision options.
 	</description>
 	<tutorials>
 	</tutorials>

doc/classes/SphereMesh.xml

@@ -15,7 +15,7 @@
 			Full height of the sphere. Defaults to 2.0.
 		</member>
 		<member name="is_hemisphere" type="bool" setter="set_is_hemisphere" getter="get_is_hemisphere">
-			Determines whether a full sphere or a hemisphere is created. Attention: To get a regular hemisphere the height and radius of the sphere have to equal. Defaults to [code]false[/code].
+			Determines whether a full sphere or a hemisphere is created. Attention: To get a regular hemisphere, the height and radius of the sphere have to equal. Defaults to [code]false[/code].
 		</member>
 		<member name="radial_segments" type="int" setter="set_radial_segments" getter="get_radial_segments">
 			Number of radial segments on the sphere. Defaults to 64.