3D Plot to SURF

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Tim Schaller
Tim Schaller on 15 Nov 2022
Answered: Torsten on 15 Nov 2022
Hi there,
my problem is, that i need the 3D Plot from down below as a SURF, but the way I thought i would need to do it, does not work at all.
So i need it to look like my 3D plot, but not just the lines, I also need the "surface".
I hope you get, what my intention is, and that somebody can help me.
Thnaks in advance.
n = 3;
n1 = n-1;
a = 20;
b = 10;
P = [0 b;0 0;a 0];
T = 15;
H = 8;
R = 2;
h = 6;
syms t s(t)
B = bernsteinMatrix(n1,t);
bezierCurve = B*P;
s(t) = int(norm(diff(bezierCurve)),0,t);
snum = linspace(0,s(1),T);
for i = 1:T
tnum(i) = vpasolve(snum(i)==s(t),t);
end
px = double(subs(bezierCurve(:,1),t,tnum)).';
py = zeros(T,1);
pz = double(subs(bezierCurve(:,2),t,tnum)).';
normalToCurve = diff(bezierCurve)*[0 1;-1 0];
normalToCurve = normalToCurve/norm(normalToCurve);
newNormalToCurve = [double(subs(normalToCurve(1),t,tnum))' double(subs(normalToCurve(2),t,tnum))'];
newNormalToCurvex = newNormalToCurve(:,1);
newNormalToCurvez = newNormalToCurve(:,2);
%%%%%%%%%%%Obere Linie
for i = 1:T
S = double(s((i-1)/(T-1)));
d = R*(1-S/double(s(1)))+(H/2)*S/double(s(1));
delta(i) = d;
end
delta = delta';
pxnew1 = px+newNormalToCurvex.*delta;
pznew1 = pz+newNormalToCurvez.*delta;
for i = 1:T
S = double(s((i-1)/(T-1)));
rhilfe = (h/2)*S/double(s(1));
r(i) = rhilfe;
end
r = r';
pynew1a = - r;
pynew1b = r;
%%%%%%%%%%Untere Linie
delta = - delta;
pxnew2 = px+newNormalToCurvex.*delta;
pznew2 = pz+newNormalToCurvez.*delta;
pynew2a = pynew1a;
pynew2b = pynew1b;
%%%%%%%%%%seitliche Linien (schwarz)
for i = 1:T
S = double(s((i-1)/(T-1)));
chilfe = R*(1-S/double(s(1)))+(h/2)*S/double(s(1));
c(i) = chilfe;
end
for i = 1:T
S = double(s((i-1)/(T-1)));
lhilfe = H/2*S/double(s(1));
l(i) = lhilfe;
end
l = l';
c = c';
pynew3 = ones(T,1).*c;
pxnew3a = px-newNormalToCurvex.*l;
pxnew3b = px+newNormalToCurvex.*l;
pznew3a = pz-newNormalToCurvez.*l;
pznew3b = pz+newNormalToCurvez.*l;
pynew3a = pynew3;
pynew3b = -pynew3;
%%%%%%%%%%%%4Ecken
%%%vorne links/rechts (magenta)
Rnewx = R*cos(pi/4);
Rnewy = R*cos(pi/4);
for i = 1:T
S = double(s((i-1)/(T-1)));
jhilfe = Rnewx*(1-S/double(s(1)))+(H/2)*S/double(s(1));
j(i) = jhilfe;
end
for i = 1:T
S = double(s((i-1)/(T-1)));
ehilfe = Rnewy*(1-S/double(s(1)))+(h/2)*S/double(s(1));
e(i) = ehilfe;
end
j = j';
e = e';
pxnew4 = px+newNormalToCurvex.*j;
pznew4 = pz+newNormalToCurvez.*j;
pynew4a = -ones(T,1).*e;
pynew4b = ones(T,1).*e;
%%%%%vorne links/recht(grün)
pxnew5 = px-newNormalToCurvex.*j;
pznew5 = pz-newNormalToCurvez.*j;
pynew5a = pynew4a;
pynew5b = pynew4b;
%%%%%%%%%%PLOTS
plot3(px,py,pz,'b-')
axis equal
axis tight
grid on
hold on
plot3(pxnew1,pynew1a,pznew1,'r-')
plot3(pxnew1,pynew1b,pznew1,'r-')
plot3(pxnew2,pynew1a,pznew2,'r-')
plot3(pxnew2,pynew1b,pznew2,'r-')
plot3(pxnew3a,pynew3a,pznew3a,'k-')
plot3(pxnew3b,pynew3a,pznew3b,'k-')
plot3(pxnew3a,pynew3b,pznew3a,'k-')
plot3(pxnew3b,pynew3b,pznew3b,'k-')
plot3(pxnew4,pynew4a,pznew4,'m-')
plot3(pxnew4,pynew4b,pznew4,'m-')
plot3(pxnew5,pynew5a,pznew5,'g-')
plot3(pxnew5,pynew5b,pznew5,'g-')
hold off
pxgesamt = [px;pxnew1; pxnew1; pxnew2; pxnew2; pxnew3a;pxnew3b;pxnew3a;pxnew3b;pxnew4; pxnew4; pxnew5; pxnew5];
pygesamt = [py;pynew1a;pynew1b;pynew2a;pynew2b;pynew3a;pynew3a;pynew3b;pynew3b;pynew4a;pynew4b;pynew5a;pynew5b];
pzgesamt = [pz;pznew1; pznew1; pznew2; pznew2; pznew3a;pznew3b;pznew3a;pznew3b;pznew4; pznew4; pznew5; pznew5];
pgesamt = [pxgesamt pygesamt pzgesamt];
surf([pxgesamt pygesamt pzgesamt]) %%%% that obviously does not work

Answers (1)

Torsten
Torsten on 15 Nov 2022
Given arrays x,y and z where the x,y values are not on a regular grid, you might want to try ScatteredInterpolant first
followed by surf or mesh.

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