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First snow this winter in Korea.

lazymatlab on 27 Nov 2024 (Edited on 27 Nov 2024)

Latest activity Edit by lazymatlab on 27 Nov 2024

So I made this.

clear
close all
clc
% inspired from: https://www.youtube.com/watch?v=3CuUmy7jX6k
%% user parameters
h = 768;
w = 1024;
N_snowflakes = 50;
%% set figure window
figure(NumberTitle="off", ...
    name='Mat-snowfalling-lab (right click to stop)', ...
    MenuBar="none")
ax = gca;
ax.XAxisLocation = 'origin';
ax.YAxisLocation = 'origin';
axis equal
axis([0, w, 0, h])
ax.Color = 'k';
ax.XAxis.Visible = 'off';
ax.YAxis.Visible = 'off';
ax.Position = [0, 0, 1, 1];
%% first snowflake
 
ht = gobjects(1, 1);
for i=1:length(ht)
    ht(i) = hgtransform();
    ht(i).UserData = snowflake_factory(h, w);
    ht(i).Matrix(2, 4) = ht(i).UserData.y;
    ht(i).Matrix(1, 4) = ht(i).UserData.x;
    im = imagesc(ht(i), ht(i).UserData.img);
    im.AlphaData = ht(i).UserData.alpha; 
    colormap gray
end
%% falling snowflake
tic;
while true
    % add a snowflake every 0.3 seconds
    if toc > 0.3
        if length(ht) < N_snowflakes
            ht = [ht; hgtransform()];
            ht(end).UserData = snowflake_factory(h, w);
            ht(end).Matrix(2, 4) = ht(end).UserData.y;
            ht(end).Matrix(1, 4) = ht(end).UserData.x;
            im = imagesc(ht(end), ht(end).UserData.img);
            im.AlphaData = ht(end).UserData.alpha;
            colormap gray
        end
        tic;
    end
    ax.CLim = [0, 0.0005]; % prevent from auto clim
    % move snowflakes
    for i = 1:length(ht)
        ht(i).Matrix(2, 4) = ht(i).Matrix(2, 4) + ht(i).UserData.velocity;
    end
    if strcmp(get(gcf, 'SelectionType'), 'alt')
        set(gcf, 'SelectionType', 'normal')
        break
    end
    drawnow
    % delete the snowflakes outside the window
    for i = length(ht):-1:1
        if ht(i).Matrix(2, 4) < -length(ht(i).Children.CData)
            delete(ht(i))
            ht(i) = [];
        end
    end
end
%% snowflake factory
function snowflake = snowflake_factory(h, w)
radius = round(rand*h/3 + 10);
sigma = radius/6;
snowflake.velocity = -rand*0.5 - 0.1;
snowflake.x = rand*w;
snowflake.y = h - radius/3;
snowflake.img = fspecial('gaussian', [radius, radius], sigma);
snowflake.alpha = snowflake.img/max(max(snowflake.img));
end