# Interpolate Points of a 3D Point Cloud?

조회 수: 114(최근 30일)
newbie 2020년 2월 21일
댓글: Diego Hens 2020년 8월 25일
I am trying to interpolate data points (x, y, z) to get a point cloud with higher density.
I have triangulation points (x-y-z coordinates) and faces from a .stl-file (imported with stlread()) that I can work with. (DATA is attached).
In the attached image you can see the given data points (BLUE) and indicated the points I want to create (RED) - but for the whole geometry and in larger numbers.
Any ideas? ##### 댓글 수: 2표시숨기기 이전 댓글 수: 1
newbie 2020년 2월 21일
I´m sorry, attached as file.

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### 채택된 답변

darova 2020년 2월 21일
• Use griddata to create surface
• Use contour3 to create crossection
clc,clear
x = data(:,1);
y = data(:,2);
z = data(:,3);
[t,r] = cart2pol(x,y);
rr = linspace(min(r),max(r),20);
tt = linspace(0,2*pi,20);
[T,R] = meshgrid(tt,rr); % new mesh
[X,Y] = pol2cart(T,R); % convert new mesh to cartesian
Z = griddata(x,y,z,X,Y); % according Z coordinates
plot3(x,y,z,'.b')
hold on
surf(X,Y,Z,'faceColor','none','edgecolor',[1 1 1]*0.8)
contour3(X,Y,Z,[34 38])
hold off
axis equal
Result ##### 댓글 수: 2표시숨기기 이전 댓글 수: 1
Diego Hens 2020년 8월 25일
Thanks, this is going to be useful. I don't know how exactly, but it will :D

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### 추가 답변(1개)

Daniel Vieira 2020년 2월 21일
try the scatteredInterpolant, should work fine with these points (not so much if you had a closed surface)
##### 댓글 수: 2표시숨기기 이전 댓글 수: 1
Daniel Vieira 2020년 2월 26일
Actually it doesn't need any function, it does exactly the same thing as griddata (others posted solutions above using it). The difference is griddata creates the interpolation over the given points and that's it, while scatteredInterpolant creates a reusable interpolator for you to use in any points you want how many times you need.

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