First day to learn Manim...
(To prepare my GRE, decide to record it in English)
Start from scratch!
A quick start!
Make a directory called learn and then make a python file scene.py
Write the code below in scene,py
from manim import *
class SquareToCircle(Scene):#define a scene named SquareToCircle
def construct(self):
circle = Circle() # create a circle
circle.set_fill(PINK, opacity=0.5) # set color and transparency
square = Square() # create a square
square.rotate(PI / 4) # rotate a certain amount
self.play(Create(square)) # animate the creation of the square
self.play(Transform(square, circle)) # interpolate the square into the circle
self.play(FadeOut(square)) # fade out animationThen play it with command line(for mac)
manim -pql scene.py SquareToCircle-p means play it
-ql means the vedio quality is low, can be substituded by -qm(mediem) -qh(high) -qk(4k)
Then it will generate several files and directories automatically.
Here is the folder structure
project/
├─scene.py
└─media
├─videos
| └─scene
| ├─480p15
| | ├─SquareToCircle.mp4
| | └─partial_movie_files
| └─1080p60
| ├─SquareToCircle.mp4
| └─partial_movie_files
├─text
└─TexThe vedio will be save as mp4 file, we can export it as gif file with the flag -i
Have a look at the animation!
squareToCircle.gif（quality medium 720p60）
Three important classes
In manim, we have 3 different concepts that you can orchestrate together to produce mathematical animations: the mathematical object (or mobject for short) the animation, and the scene.
Each of these three concepts is implemented in manim as a separate class: the , , and classes.
Mobjects
How to create
Mobjects is a very basic concept for manim animation.
Each class that derives from represents an object that can be displayed on the screen. For example, simple shapes such as , , and are all mobjects. More complicated constructs such as , , or are mobjects as well.
We cannot directly play a on the scene for the class is an abstract base class of all other mobjects. It doesn't has a pre-determined visual shape.
So, mobjects is just a general concept. When it comes to the real case, we often use its derived class, for example the VMobjects, which V represents vector.
If we want a mobjects to be displayed, skills below can be useful
from manim import *
class CreatingMobjects(Scene):
def construct(self):
circle = Circle()
self.add(circle)
self.wait(1)
self.remove(circle)
self.wait(1)We use the methods add() and remove() to display a single mobject Circle.
Here is the output GIF:
CreatingMobjects.gif(quality low 480p15)
How to place
we have several method for position
For example shift()
from manim import *
class PlaceShapesWithShift(Scene):
def construct(self):
circle = Circle()
square = Square()
triangle = Triangle()
circle.shift(LEFT)
square.shift(UP)
triangle.shift(RIGHT)
self.add(circle, square, triangle)
self.wait(1)output
PlaceShapesWithShift.gif
also we have other methods like next_to( ) move_to( ) align_to( )
Example
from manim import *
class MobjectPlacement(Scene):
def construct(self):
circle = Circle()
square = Square()
triangle = Triangle()
# place the circle two units left from the origin
circle.move_to(LEFT * 2)
# place the square to the left of the circle
square.next_to(circle, LEFT)
# align the left border of the triangle to the left border of the circle
triangle.align_to(circle, LEFT)
self.add(circle, square, triangle)
self.wait(1)and the output
MobjectPlacement.gif
Add Style
We can apply different styles on the mobjects with many methods.
set_stroke( ) set_fill( ) ......
from manim import *
class MobjectZOrder(Scene):
def construct(self):
circle = Circle().shift(LEFT)
square = Square().shift(UP)
triangle = Triangle().shift(RIGHT)
circle.set_stroke(color=GREEN, width=20)
square.set_fill(YELLOW, opacity=1.0)
triangle.set_fill(PINK, opacity=0.5)
self.add(triangle, square, circle)
self.wait(1)Notice here the add(triangle, square, circle) has sequence.
Animation
At the heart of manim is animation. Generally, we can add an animation to our scene by calling the method.
from manim import *
class SomeAnimations(Scene):
def construct(self):
square = Square()
self.add(square)
# some animations display mobjects, ...
self.play(FadeIn(square))
# ... some move or rotate mobjects around...
self.play(Rotate(square, PI/4))
# some animations remove mobjects from the screen
self.play(FadeOut(square))
self.wait(1)
Animating methods
Any property of a mobject that can be changed can be animated. In fact, any method that changes a mobject’s property can be used as an animation, through the use of .
from manim import *
class AnimateExample(Scene):
def construct(self):
square = Square().set_fill(RED, opacity=1.0)
self.add(square)
# animate the change of color
self.play(square.animate.set_fill(WHITE))
self.wait(1)
# animate the change of position and the rotation at the same time
self.play(square.animate.shift(UP).rotate(PI / 3))
self.wait(1)
is a property of all mobjects that animates the methods that come afterward. For example, sets the fill color of the square, while animates this action.
That's all for taday's record. Actually I learned more than what I post here, but it's too much and I have to learn something else today Leave it to next share!
By the way, the progress of my learning is a little bit fast. I draftly know how to display euler's angles by Manim. But of course, still too many details not known.
