What's the best way to interpolate the vertices of a polygon?

What's the best way to interpolate the vertices of a polygon?

Take a triangle with vertices

pKL = [429 92; 326 334; 459 98];
interpp = 5;

interp2(pKL,interpp) % NO!
resample(pKL,interpp,1)) % NO!

How can I get interpp=5 points between 429 and 326, then 326 and 459, then 459 back to 429 in the x direction, and the same idea in the y direction, and combine it all in a single 2D array? I tried interp2d and resample, but it doesn't work. I can do it with a loop, but that feels like too many lines of code.

Answer 1

[darova]

The best way is described here: Interpolation of 3D point data

[mark palmer]

THANKS! I got the following code to work

pKL = [429 92; 326 334; 459 98]; % TEST ONLY
% X AND Y ARE SWAPPED FOR EXTERNAL REASONS
rx = pKL(:,2)';
ry = pKL(:,1)';
rx = [rx rx(1)];
ry = [ry ry(1)];
inD = 5;
pt = interparc(inD, rx(1:2), ry(1:2), 'spline')

ANS:
pt =
   92.0000  429.0000
  152.5000  403.2500
  213.0000  377.5000
  273.5000  351.7500
  334.0000  326.0000

but not the example that doesn't use the special function interparc:

t = [0;cumsum(sqrt(diff(rx).^2+diff(ry).^2))];
t = t/t(end);
ti = linspace(0,1,5);
xx = spline(t,x,ti);
yy = spline(t,y,ti);

Anyway, thanks again!

[darova]

im just doing my job