Merge pull request #1013 from skyace65/Reorganize_particle_systems(2D)

Underline fixes

learning/features/2d/particle_systems_2d.rst

@@ -50,10 +50,10 @@ the relevant texture property:
 .. image:: img/particles2.png
 
 Time Parameters
-===============
+---------------
 
 Lifetime
---------
+~~~~~~~~
 
 The time in seconds that every particle will stay alive. When lifetime
 ends, a new particle is created to replace it.
@@ -67,13 +67,13 @@ Lifetime: 4.0
 .. image:: img/paranim15.gif
 
 One Shot
---------
+~~~~~~~~
 
 When enabled, a Particles2D node will emit all of its particles once
 and then never again.
 
 Preprocess
-----------
+~~~~~~~~~~
 
 Particle systems begin with zero particles emitted, then start emitting.
 This can be an inconvenience when just loading a scene and systems like
@@ -82,14 +82,14 @@ used to let the system process a given number of seconds before it is
 actually drawn the first time.
 
 Speed Scale
------------
+~~~~~~~~~~~
 
 The speed scale has a default value of ``1``, and is used to adjust the
 speed of a particle system. Lowering the value will make the particles 
 slower, increasing the value will make the particles much faster.
 
 Explosiveness
--------------
+~~~~~~~~~~~~~
 
 If lifetime is ``1`` and there are ten particles, it means a particle
 will be emitted every 0.1 seconds. The explosiveness parameter changes
@@ -104,7 +104,7 @@ creating explosions or sudden bursts of particles:
 .. image:: img/paranim18.gif
 
 Randomness
-----------
+~~~~~~~~~~
 
 All physics parameters can be randomized. Random values range from ``0`` to
 ``1``. The formula to randomize a parameter is:
@@ -114,29 +114,29 @@ All physics parameters can be randomized. Random values range from ``0`` to
     initial_value = param_value + param_value * randomness
 
 Fixed FPS
----------
+~~~~~~~~~
 
 This setting can be used to set the particle system to render at a fixed 
 FPS. For instance, changing the value to ``2`` will make the particles render
 at 2 frames per second. Note this does not slow down the particle system itself.
 
 Fract Delta
------------
+~~~~~~~~~~~
 
 This can be used to turn Fract Delta on or off.
 
 Drawing Parameters 
-==================
+------------------
 
 Visability Rect
----------------
+~~~~~~~~~~~~~~~
  
 The ``W`` and ``H`` values control width and height of the visibility
 rectangle. The ``X`` and ``Y`` values control the position of the upper-left
 corner of the visibility rectangle relative to the particle emitter.
 
 Local Coords
-------------
+~~~~~~~~~~~~
 
 By default this option is on, and it means that the space that particles
 are emitted to is relative to the node. If the node is moved, all
@@ -150,17 +150,17 @@ node is moved, already emitted particles are not affected:
 .. image:: img/paranim21.gif
 
 Draw Order
-----------
+~~~~~~~~~~
 
 This controls the order in which individual particles are drawn. ``Index``
 means particles are drawn according to their emission order (default).
 ``Lifetime`` means they are drawn in order of remaining lifetime.
 
 ParticlesMaterial settings
-==========================
+--------------------------
 
 Direction
----------
+~~~~~~~~~
 
 This is the base angle at which particles emit. Default is ``0`` (down):
 
@@ -175,7 +175,7 @@ This parameter is useful because, by rotating the node, gravity will
 also be rotated. Changing direction allows them to be separated.
 
 Spread
-------
+~~~~~~
 
 This parameter is the angle in degrees which will be randomly added in
 either direction to the base ``Direction``. A spread of ``180`` will emit
@@ -184,14 +184,14 @@ in all directions (+/- 180).
 .. image:: img/paranim3.gif
 
 Gravity
--------
+~~~~~~~
 
 The gravity applied to every particle. 
 
 .. image:: img/paranim7.gif
 
 Initial Velocity
-----------------
+~~~~~~~~~~~~~~~~
 
 Linear velocity is the speed at which particles will be emitted (in
 pixels/sec). Speed might later be modified by gravity or other
@@ -200,12 +200,12 @@ accelerations (as described further below).
 .. image:: img/paranim4.gif
 
 Angular Velocity
-----------------
+~~~~~~~~~~~~~~~~
 
 Angular velocity is the inital angular velocity applied to particles.
 
 Spin Velocity
--------------
+~~~~~~~~~~~~~
 
 Spin velocity is the speed at which particles turn around their center
 (in degrees/sec).
@@ -213,19 +213,19 @@ Spin velocity is the speed at which particles turn around their center
 .. image:: img/paranim5.gif
 
 Orbit Velocity
---------------
+~~~~~~~~~~~~~~
 
 Orbit velocity is used to make particles turn around their center.
 
 .. image:: img/paranim6.gif
 
 Linear Acceleration
--------------------
+~~~~~~~~~~~~~~~~~~~
 
 The linear acceleration applied to each particle.
 
 Radial Acceleration
--------------------
+~~~~~~~~~~~~~~~~~~~
 
 If this acceleration is positive, particles are accelerated away from
 the center. If negative, they are absorbed towards it.
@@ -233,7 +233,7 @@ the center. If negative, they are absorbed towards it.
 .. image:: img/paranim8.gif
 
 Tangential Acceleration
------------------------
+~~~~~~~~~~~~~~~~~~~~~~~
 
 This acceleration will use the tangent vector to the center. Combining
 with radial acceleration can do nice effects.
@@ -241,7 +241,7 @@ with radial acceleration can do nice effects.
 .. image:: img/paranim9.gif
 
 Damping
--------
+~~~~~~~
 
 Damping applies friction to the particles, forcing them to stop. It is
 especially useful for sparks or explosions, which usually begin with a
@@ -250,7 +250,7 @@ high linear velocity and then stop as they fade.
 .. image:: img/paranim10.gif
 
 Angle
------
+~~~~~
 
 Determines the initial angle of the particle (in degress). This parameter
 is mostly useful randomized.
@@ -258,19 +258,19 @@ is mostly useful randomized.
 .. image:: img/paranim11.gif
 
 Scale
------
+~~~~~
 
 Determines the initial scale of the particles.
 
 .. image:: img/paranim12.gif
 
 Color
------
+~~~~~
 
 Used to change the color of the particles being emitted.
 
 Hue variation
--------------
+~~~~~~~~~~~~~
 
 The variation value sets the inital hue variation applied to each 
 particle. The Variation rand value controls the hue variation