How to remove a 3d-Surface matrix entries outside of a 2D area/Curve?

Hello lovely Mathworks members,

( I tried to find similar question but could not find any, so excuse me if there is already existing answer please share the link)

There is a 3D surface matrix which has some entries outside of a curve area and I want to remove the 3D matrix entries outside of a 2D curve. Can someone please help to understand how to remove the outside of curve entries of the 3D matrix. In attachmnet you will find both 2D and 3D matrices.

Best Regards!

Answer 1

[KSSV]

You hvae to use inpolygon. Read about it.

load('3D_XYZ_Data.mat') ;
load('2D_RestrictedArea.mat') ;

X = XYZ_Data(:,1) ; 
Y = XYZ_Data(:,2) ; 
Z = XYZ_Data(:,3) ; 

x = Restricted_Area(:,1) ; 
y = Restricted_Area(:,2) ; 

idx = inpolygon(X,Y,x,y) ; % get points lying inside the restricted points 
plot3(X(idx),Y(idx),Z(idx),'.r')
hold on
plot(x,y,'.b')
view(2)

[Garvit Amipara]

Thank you so much @KSSV , I didn't know this before. The 'inpolygon' function is exactly what I needed!

There is a small issue. As in the image below, when I used the code you wrote, it worked for the entries on the top-side of the curve but on the bottom side there are still some entries which are not being removed by inpolygon. Could you please help?

[KSSV]

Hey actually code works fine. You need not to use boundary. I am edititng the code. You should get fine result now.

[Garvit Amipara]

Amazing!! Works perfectly. Thank you so much<3