1, Introduction

Matlab has powerful visual function, and it can also be used to make animation. The simplest way to realize animation is to set the action route of the target primitive, and then use the circular statement and pause command to update the position of the primitive, so that the animation is completed.

This article takes three swallows (which can be understood as a family of three, haha) flying in a certain area as an example, and takes you step by step to learn the production of simple animation.

2, Simple animation steps

1. Draw animated target graphics

1) To draw a swallow, you can use the sine curve splicing method (a little simple, like a simple hard stroke). The specific methods are as follows:

Take the sine curve between 0 and PI as the wing of a swallow

The curve between 0~pi/2 is regarded as the right wing

The curve between pi/2 and PI is regarded as the left wing

The code is as follows:

x1 = [ 0:0.01:1/2 ] * pi;%Abscissa of right wing y1 = sin( x1 ); %Right wing ordinate x2 = [ 1/2:0.001:1 ] * pi;%Abscissa of left wing y2 = sin( x2 ); %Left wing ordinate p1 = plot( (x1+pi)/2, (y1+3)/2, 'k' );%The right wing is on the right, so it needs“+pi" hold on p2 = plot( x2/2, (y2+3)/2, 'k' ); axis( [ -8, 10, 0, 10 ] )

Drawing result: (a little lonely)

2) Draw another two swallows and follow the above practice. The code is as follows:

p3 = plot( (x1+pi)/2+2, (y1+3)/3, 'k' ); p4 = plot( x2/2+2, (y2+3)/3 , 'k' ); p5 = plot( (x1+pi)/3-2, (y1+3)/3, 'k' ); p6 = plot( x2/3-2, (y2+3)/3, 'k' );

The results are shown in the following figure:

Did you find it so easy to draw a swallow here. Of course, it's more like a goose.

2. Set the scene

1) Add a background color to the rectangular area

%Add a background color to the rectangular area

axis( [ -8, 10, 0, 10 ] ) set( gca, 'color', [ 1, 1, 0.9 ] );%gca Represents the current drawing area

2) Draw another red sun

%Draw red sun t = (0:0.1:2) * pi; x = 0.5 * cos(t) + 8; y = 0.5 * sin(t) + 9; fill( x, y, 'r' ) axis equal axis( [ -8, 10, 0, 10 ] )%This sentence is used to readjust the drawing area

The image window obtained at this time is shown in the following figure:

3) Draw two more (see if the background is richer in this way)

%Draw two mountains

xh = [ -8 : 0.2 : 8 ]; yh1 = 2 * exp( -(xh + 5).^2 / 2 ); fill( xh, yh1, 'b' ) hold on yh2 = 1.5 * exp( -xh.^2 / 4 ); area( xh, yh2, 'FaceColor', [ 0.1, 0.1, 0.9 ] );

At this point, the background of the animation becomes as shown in the figure below. Does it look a little better than the figure in the previous step. Of course, you can also design more beautiful.

3. Plan your route

Suppose the swallow moves along a sine curve or cosine curve

path_x = [-2 : 0.01 : 2] *pi;%Abscissa path_y1 = sin( dir ); %The flight path of the first swallow path_y2 = cos( dir ); %The flight path of the second swallow path_y3 = cos( fliplr(dir) );%The flight path of the third swallow

4. Sports design

Put the three swallows into the specified initial position, and then use the set command to modify the position coordinates of the image handles (p1,p2), (p3,p4) and (p5,p6) corresponding to each swallow to realize the position change of the swallows. Coupled with the loop statement and pause command, the flying animation of the swallow can be realized. The code is as follows (taking five flight cycles as an example, the value of the cycle can also be modified, or it can be directly changed to an endless cycle):

hight = 2;%Set the initial height of the swallow period = 5; %Motor cycle k = 0; len = length( path_x ); while k < period for i = 1 : len set( p1, 'Xdata', path_x(i) +(x1+pi)/2, 'Ydata', path_y1(i)+2 + (y1+3)/2 + hight ); set( p2, 'Xdata', path_x(i) + x2/2, 'Ydata', path_y1(i) + 2 + (y2+3)/2 + hight ); set( p3, 'Xdata', path_x(i)-2 + (x1+pi)/2, 'Ydata', path_y2(i)+2 + (y1+3)/3 + hight ); set( p4, 'Xdata', path_x(i)-2 + x2/2, 'Ydata', path_y2(i) + 2 + (y2+3)/3 + hight ); set( p5, 'Xdata', path_x(len-i+1) + (x1+pi)/3, 'Ydata', path_y3(i) + 2 + (y1+3)/3 + hight ); set( p6, 'Xdata', path_x(len-i+1) + x2/3, 'Ydata', path_y3(i) + 2 + (y2+3)/3 + hight ); pause(0.02); end path_x = fliplr( path_x );%Reverse return flight k = k + 1; end

At this point, the simple animation of the swallow flying in a scene is completed.

Two scenes in flight are as follows:

3, Complete code

%Take 0~pi The sine curve between the wings of swallows %0~pi/2 Between the curves as the right wing %pi/2~pi Between the curves as the left wing clear all clc x1 = [ 0:0.01:1/2 ] * pi;%Abscissa of right wing y1 = sin( x1 ); %Right wing ordinate x2 = [ 1/2:0.001:1 ] * pi;%Abscissa of left wing y2 = sin( x2 ); %Left wing ordinate p1 = plot( (x1+pi)/2, (y1+3)/2, 'k' );%The right wing is on the right, so it needs“+pi" hold on p2 = plot( x2/2, (y2+3)/2, 'k' ); axis( [ -8, 10, 0, 10 ] ) %Rectangular area in the planning area p3 = plot( (x1+pi)/2+2, (y1+3)/3 + 3, 'k' ); p4 = plot( x2/2+2, (y2+3)/3 + 3 , 'k' ); p5 = plot( (x1+pi)/3-2, (y1+3)/3 + 1, 'k' ); p6 = plot( x2/3-2, (y2+3)/3 + 1, 'k' ); %Add a background color to the rectangular area axis( [ -8, 10, 0, 10 ] ) %set( gcf, 'doublebuffer', 'on'); set( gca, 'color', [ 1, 1, 0.9 ] );%gca Represents the current drawing area %Draw red sun t = (0:0.1:2) * pi; x = 0.5 * cos(t) + 8; y = 0.5 * sin(t) + 9; fill( x, y, 'r' ) axis equal axis( [ -8, 10, 0, 10 ] ) %Draw two mountains xh = [ -8 : 0.2 : 8 ]; yh1 = 2 * exp( -(xh + 5).^2 / 2 ); fill( xh, yh1, 'b' ) hold on yh2 = 1.5 * exp( -xh.^2 / 4 ); area( xh, yh2, 'FaceColor', [ 0.1, 0.1, 0.9 ] ); %Movement route path_x = [-2 : 0.01 : 2] *pi;%Abscissa path_y1 = sin( path_x ); %The flight path of the first swallow path_y2 = cos( path_x ); %The flight path of the second swallow path_y3 = cos( fliplr(path_x) );%The flight path of the third swallow set( gcf, 'doublebuffer', 'on'); hight = 2;%Set the initial height of the swallow period = 5; %Motor cycle k = 0; len = length( path_x ); while k < period for i = 1 : len set( p1, 'Xdata', path_x(i) +(x1+pi)/2, 'Ydata', path_y1(i)+2 + (y1+3)/2 + hight ); set( p2, 'Xdata', path_x(i) + x2/2, 'Ydata', path_y1(i) + 2 + (y2+3)/2 + hight ); set( p3, 'Xdata', path_x(i)-2 + (x1+pi)/2, 'Ydata', path_y2(i)+2 + (y1+3)/3 + hight ); set( p4, 'Xdata', path_x(i)-2 + x2/2, 'Ydata', path_y2(i) + 2 + (y2+3)/3 + hight ); set( p5, 'Xdata', path_x(len-i+1) + (x1+pi)/3, 'Ydata', path_y3(i) + 2 + (y1+3)/3 + hight ); set( p6, 'Xdata', path_x(len-i+1) + x2/3, 'Ydata', path_y3(i) + 2 + (y2+3)/3 + hight ); pause(0.02); end path_x = fliplr( path_x );%Reverse return flight k = k + 1; end