鑽石舞台

close all;clear;clc

% setup

snow=450; % number of snow flakes [0 .. 5000]

% draw tree

h=0:0.2:25; %vertical grid

[X,Y,Z] = cylinder(tree(h)); %produce a tree formed cylinder

Z=Z*25; %scale to the right heigth

%Add some diffusion to the surface of the tree to make it look more real

treeDiffusion=rand(126,21)-0.5;%some horizontal diffusion data

%add diffusion to the grid points

for cnt1=1:21

for cnt2=16:126%starting above the trunk

%get the angle to always diffuse in direction of the radius

angle=atan(Y(cnt2,cnt1)/X(cnt2,cnt1));

%split the diffusion in the two coordinates, depending on the angle

X(cnt2,cnt1)=X(cnt2,cnt1)+cos(angle)*treeDiffusion(cnt2,cnt1);

Y(cnt2,cnt1)=Y(cnt2,cnt1)+sin(angle)*treeDiffusion(cnt2,cnt1);

%some Vertical diffusion for each point

Z(cnt2,cnt1)=Z(cnt2,cnt1)+(rand-0.5)*0.5;

end

end

%draw the tree

h0 = figure('Units','inches');

pos = h0.Position;

pos(1) = 1; pos(2) = 1;

pos(3) = 7; pos(4) = 7;

h0.Position = pos;

surfl(X,Y,Z,'light')

%% View and format

%Use as nice green color map (darker at the bottom, lighter at the top)

r=(0.0430:(0.2061/50):0.2491)';%red component

g=(0.2969:(0.4012/50):0.6981)';%green component

b=(0.0625:(0.2696/50):0.3321)';%blue component

map=[r,g,b];%join in a map

for cnt=1:6

%change the lower part to brown for the trunk

map(cnt,:)=[77,63,5]/265;

end

colormap(map)%set the map

view([-37.5,4])%Change the view to see a little more of the Actual 3D tree

lighting phong %some nice lighting

shading interp %remove grid and smoothen the surface color

axis equal %takes care of display in the right proportion

axis([-10 10 -10 10 0 30]) %give some more axis space (for the snow later)

axis off %but don't show axis

hold on %to draw the rest

title('Merry Christmas','color','w',...

'fontsize',25,...

'fontweight','Bold')%self explaining

set(gcf,'color',[22 32 51]./255)

% Presents

%Draw some presents around the tree (each with random color)

drawPresent(2,-4,0,3,3,2);

drawPresent(-4,3,0,2,3,1.5);

drawPresent(5,3,0,4,3,3);

drawPresent(-14,-5,0,6,3,1);

drawPresent(-9,-10,0,2,2,2);

drawPresent(0,4,0,4,3,3);

drawPresent(-6,-13,0,3,3,3);

%% Snow

%create some random 3D coordinates for the snow (amount as in setup above)

snowX=(rand(snow-100,1)*25-12.5);

snowY=(rand(snow-100,1)*25-12.5);

snowZ=(rand(snow-100,1)*27);

color0 = jet(length(snowX));

%Note:Some flakes will end up IN the tree but just can't be seen then

for ii = 1:length(snowX)

plot3(snowX(ii),snowY(ii),snowZ(ii),'*','color',color0(ii, :),'markersize',randi(15))%plot coordinates as white snow flakes

% plot3(snowX(ii),snowY(ii),snowZ(ii),'*','color',color0(ii, :))%plot coordinates as white snow flakes

end

h=plot3(snowX,snowY,snowZ,'w*');

im = {};

for ii = 1:180

if mod(ii,3) == 0

h.Visible = 'off';

snowX=(rand(snow,1)*25-12.5);

snowY=(rand(snow,1)*25-12.5);

snowZ=(rand(snow,1)*27);

h=plot3(snowX,snowY,snowZ,'w*');

% pause(0.25)

else

view([ii,4])

% pause(0.1)

end

if ii > 85

frame = getframe(gcf);

im{ii} = frame2im(frame);

end

end

hold off%Done

im(cellfun(@isempty,im))=[];

% end % of function

file2write = 'chris.gif';

for ii = 1:length(im)

[A, map] = rgb2ind( im{ii}, 256);

if ii == 1

imwrite(A, map, file2write, 'gif','LoopCount',Inf,'DelayTime', 0.12);

else

imwrite(A, map, file2write, 'gif','WriteMode','append','DelayTime', 0.12);

end

end

%% ============= private functions

function r=tree(h)%Gives a profile for the tree

for cnt=1:length(h)

if(h(cnt)==0)%no Width at the bottom. Ensures a "closed" trunk

r(cnt)=0;

end

%smaller radius for the trunk

if (h(cnt)>0 && h(cnt)<=3)

r(cnt)=1.5;

end

%reduce radius gradually from 8 to 0. Note: will only work with a trunk heigth

%of 3 and a whole tree heigth of 25. Scale the height of the tree in

%the "draw tree" section, since the cylinder command will return a 1

%unit high cylinder anyway

if(h(cnt)>3)

r(cnt)=8-(h(cnt)-3)*0.3636;

end

end

end % of function

%Draws a present with the given coordinate + size in a random color

%Note:Given coordinates apply to the lower front + left corner of the

%present (the one closest to the viewer) as seen in the plot

function drawPresent(dx,dy,dz,scalex,scaley,scalez)

%the standard present coordinates

presentX=[0.5 0.5 0.5 0.5 0.5; 0 1 1 0 0; 0 1 1 0 0; 0 1 1 0 0; 0.5 0.5 0.5 0.5 0.5];

presentY=[0.5 0.5 0.5 0.5 0.5; 0 0 1 1 0; 0 0 1 1 0; 0 0 1 1 0; 0.5 0.5 0.5 0.5 0.5];

presentZ=[0 0 0 0 0; 0 0 0 0 0; 0.5 0.5 0.5 0.5 0.5; 1 1 1 1 1; 1 1 1 1 1];

%draw some presents with random colors

%scale present and move it to the right place and get the plot handle

myHandle=surf((presentX*scalex+dx),(presentY*scaley+dy), (presentZ*scalez+dz));

%some random color map

randColorMap(:,:,1)=repmat(rand,[5,5]);%r component

randColorMap(:,:,2)=repmat(rand,[5,5]);%g component

randColorMap(:,:,3)=repmat(rand,[5,5]);%b component

%Assign colormap just to the plot handle object of the present, so the tree

%does not change color

set(myHandle,'CData',randColorMap)

shading interp %Nice shding + without grid

end % of function