Project the areas on the 3d model(car)

Hello everyone,

I need help about some coding. I have the 3d model of a car and some areas around the car(actually at the side doors in the photo). I want that areas to be in the shape of 3d model. It is actually ok for the side door but imagine plotting it for the front, it would not be as same curvature as the front of the car has. How can I do it? Any ideas? It may be the projection of the areas on 3d model or something? If it even exist.

I use stlRead to read the 3d model and fill3 to plot the areas(as I have x y z coordinates).

[darova]

Can you be more specific? What do you mean by 'projection'?

[Umut Ege Ulucay]

Hello, if you see the side door for example in the second photo, I want my areas to be same shape as the 3d model. I have an area rectengle area in the side door of the car but as you can see in the second picture, It does not have the same shape as the door. I actually mean my areas to take the shape of a door like in the same picture. I want to have my areas colored like second picture but in the shape of first picture. sorry if its too complicated to tell, thank you again.

[darova]

Did you try to cut out the door only? something like inpolygon

clc,clear
cla
d1 = [0.4104    0.6557
    0.2142    0.4443
    0.2160    0.1739
    0.7047    0.1807
    0.6934    0.6489
    0.4104    0.6557];
xd = d1(:,1);
yd = d1(:,2);
x = rand(100,1);
y = rand(100,1);
in = inpolygon(x,y,xd,yd);
plot(x,y,'.r')
hold on
plot(xd,yd)
plot(x(in),y(in),'or')
hold off
legend('all points','door','points inside')

You can draw the door manually using impoly

p = impoly;
p.getPosition

[Umut Ege Ulucay]

Yes, you actually gave me a good idea to change my point of view. I can work with inpolygon but I need to make it in 3d. I will look for it thanks a lot but, you can give me idea if you still have so. Thank you

Answer 1

[darova]

Here is a simple example. Should be heplfull

clc,clear

[x,y,z] = sphere(30);
ix = x > 0;                 % select half of the sphere only
    % door coordinates
d1 = [0.4104    0.6557      
    0.2142    0.4443
    0.2160    0.1739
    0.7047    0.1807
    0.6934    0.6489
    0.4104    0.6557];
yd = d1(:,1)-0.5;
zd = d1(:,2);
gd = [2; length(yd); yd(:); zd(:)];     % door geometry
dl = decsg(gd);                         % decomposition of geometry
[p,e,t] = initmesh(dl);                 % create mesh
ydt = p(1,:)';                          % Y coord of the door
zdt = p(2,:)';                          % Z coord of the door
xdt = griddata(y(ix),z(ix),x(ix),ydt,zdt);  % interpolate X coord

ff.vertices = [xdt ydt zdt];
ff.faces    = t(1:3,:)';
ff.facecolor= 'yellow';
surf(x,y,z,'facecolor','none','edgecolor',[1 1 1]*0.8)
line(yd*0+1.2,yd,zd,'linew',2)
patch(ff)

axis vis3d equal