主要學習了畫空間圓柱體和空間長方形的繪製方法。
有兩個surface property：'FaceColor'和‘EdgeColor’;
先講‘FaceColor’，它指定了surface畫出曲面的顏色，可以是[r,g,b]的一個向量，分別表示了紅綠藍的顏色配比；
也可以是‘interp’，畫出來是由z的值決定的漸變色，可以使用colormapeditor來調節顏色（在代碼中寫上colormapeditor即可喚出調色板）；
然後是‘EdgeColor’，它會在曲面的表面畫出網格，指定顏色的方法同上。
但是有一個疑問沒有解決：就是如何只顯示各個棱的網格線，而不是整個面的網格線？？這個留待後面繼續摸索吧。
surface(x,y,z)函數畫出來的圖像如果想要平移，可以直接在帶入參數時修改。比如，沿z軸正方向平移10，就是surface(x,y,z+10);
最後有一個實現視角自動旋轉的小功能：
view（az,el）中，az可以調節物體旋轉的角度，el調節攝像機的俯仰角度
for i=1:120
view(i*1, 30);
pause(0.01);
end代碼如下:
function test()
%%
clear;
clc;
clf;
z_delta = 6;
%% draw head
A = imread('head.jpg');
[x,y,z]=sphere(30);
h0=surface(x,y,z + z_delta,'EdgeColor','none');
rotate(h0, [0,0,1], 90);
set(h0,'CData',A,'FaceColor','texturemap');%texturemap紋理貼圖
%% draw body
% FaceColor (orange)
face_color = 'interp'; %[1, 0.6, 0];
edge_color = 'b';
<pre name="code" class="plain">colormapeditor; function [Cylinder, EndPlate1, EndPlate2] = cylinder3(X1,X2,r,n,cyl_color,closed,lines)
%
% This function constructs a cylinder connecting two center points
%
% Usage :
% [Cylinder EndPlate1 EndPlate2] = cylinder3(X1+20,X2,r,n,'r',closed,lines)
%
% Cylinder-------Handle of the cylinder
% EndPlate1------Handle of the Starting End plate
% EndPlate2------Handle of the Ending End plate
% X1 and X2 are the 3x1 vectors of the two points
% r is the radius of the cylinder
% n is the no. of elements on the cylinder circumference (more--> refined)
% cyl_color is the color definition like 'r','b',[0.52 0.52 0.52]
% closed=1 for closed cylinder or 0 for hollow open cylinder
% lines=1 for displaying the line segments on the cylinder 0 for only
% surface
%
% Typical Inputs
% X1=[10 10 10];
% X2=[35 20 40];
% r=1;
% n=20;
% cyl_color='b';
% closed=1;
%
% NOTE: There is a MATLAB function "cylinder" to revolve a curve about an
% axis. This "Cylinder" provides more customization like direction and etc
%%%%%%%%%%
if (X1(1) > X2(1))
tmpX = X1; X1 = X2; X2 = tmpX;
end
% Calculating the length of the cylinder
length_cyl=norm(X2-X1);
% Creating a circle in the YZ plane
t=linspace(0,2*pi,n)';
x2=r*cos(t);
x3=r*sin(t);
% Creating the points in the X-Direction
x1=[0 length_cyl];
% Creating (Extruding) the cylinder points in the X-Directions
xx1=repmat(x1,length(x2),1);
xx2=repmat(x2,1,2);
xx3=repmat(x3,1,2);
% Drawing two filled cirlces to close the cylinder
if closed==1
hold on
EndPlate1=fill3(xx1(:,1),xx2(:,1),xx3(:,1),'r');
EndPlate2=fill3(xx1(:,2),xx2(:,2),xx3(:,2),'r');
end
% Plotting the cylinder along the X-Direction with required length starting
% from Origin
Cylinder=mesh(xx1,xx2,xx3);
% Defining Unit vector along the X-direction
unit_Vx=[1 0 0];
% Calulating the angle between the x direction and the required direction
% of cylinder through dot product
angle_X1X2=acos( dot( unit_Vx,(X2-X1) )/( norm(unit_Vx)*norm(X2-X1)) )*180/pi;
% Finding the axis of rotation (single rotation) to roate the cylinder in
% X-direction to the required arbitrary direction through cross product
axis_rot=cross([1 0 0],(X2-X1) );
% Rotating the plotted cylinder and the end plate circles to the required
% angles
if angle_X1X2~=0 % Rotation is not needed if required direction is along X
rotate(Cylinder,axis_rot,angle_X1X2,[0 0 0])
if closed==1
rotate(EndPlate1,axis_rot,angle_X1X2,[0 0 0])
rotate(EndPlate2,axis_rot,angle_X1X2,[0 0 0])
end
end
% Till now cylinder has only been aligned with the required direction, but
% position starts from the origin. so it will now be shifted to the right
% position
if closed==1
set(EndPlate1,'XData',get(EndPlate1,'XData')+X1(1))
set(EndPlate1,'YData',get(EndPlate1,'YData')+X1(2))
set(EndPlate1,'ZData',get(EndPlate1,'ZData')+X1(3))
set(EndPlate2,'XData',get(EndPlate2,'XData')+X1(1))
set(EndPlate2,'YData',get(EndPlate2,'YData')+X1(2))
set(EndPlate2,'ZData',get(EndPlate2,'ZData')+X1(3))
end
set(Cylinder,'XData',get(Cylinder,'XData')+X1(1))
set(Cylinder,'YData',get(Cylinder,'YData')+X1(2))
set(Cylinder,'ZData',get(Cylinder,'ZData')+X1(3))
% Setting the color to the cylinder and the end plates
set(Cylinder,'FaceColor',cyl_color)
if closed==1
set([EndPlate1 EndPlate2],'FaceColor',cyl_color)
else
EndPlate1=[];
EndPlate2=[];
end
% If lines are not needed making it disapear
if lines==0
set(Cylinder,'EdgeAlpha',0)
end
