How to rotate an Alpha Shape, or points that defines the edge of a 3D shape?

Hello,

I am trying to rotate a 3-D surface which composed of 1000 points defined in space. I turned these points to a surface by using alphashape function.

I tried to rotate with "rotate" function but, I got type error;

Error in rotate (line 59)
t = get(h(i),'type');

Can you suggest me a solution?

For additional information, please ask it.

Thanks in advance, Mücahit

Answer 1

[Mike Garrity]

Could you post your code?

Here's a modified version of one of the examples:

[x1, y1, z1] = sphere(24);
x1 = x1(:);
y1 = y1(:);
z1 = z1(:);
x2 = x1+5;
P = [x1 y1 z1; x2 y1 z1];
P = unique(P,'rows');
shp = alphaShape(P,1)
h = plot(shp);
axis vis3d

for i=1:12
  rotate(h,[1 1 1],30)
  pause(.25)
end

[Mücahit Gürbüz]

Thank you Mike,

My code as follows;

    clc
    clear all

    [P]=Rock1(15);

    as_rock = alphaShape(P(:,1),P(:,2),P(:,3),4);
    plot(as_rock,'FaceColor',[218 136 86]./255,'EdgeAlpha',0)  %plot the rock
    title('Simulated Figure') %create a title 
    lighting gouraud %lighting
    light('Position',[100 -200 50],'Style','local') %light position
    axis equal  % realistic axes

    direction = [1 0 0];
    origin = [P(1,1) P(1,2) P(1,3)];
    rotate(as_rock,direction,25,origin);

And the Rock1 function as follows;

    function [ P ] = Rock1( D )  %input arguments Diameter and returns a defined Rock points with diameter D 
x=randn(1000,1); %assign normally distributed random numbers 
multi_x1=D/(max(x)-min(x)); %to make its diameter, find its current diameter with max-min function and find its multiplyer
x11= (multi_x1*x); %final x coordinates assigned here
y=randn(1000,1);
multi_y1=D/(max(y)-min(y));
y11=(multi_y1*y);
z=randn(1000,1);
multi_z1=D/(max(z)-min(z));
z11=multi_z1*z;
P = [x11 y11 z11]; %output argument like points on space that defines our rocks
end

Thank you!

[Mike Garrity]

Ah, the rotate function wants the handle of the graphics object, not the alphaShape. The graphics object is created by the plot function. So you need something like:

h = plot(as_rock,'FaceColor', ...
...
rotate(h,direction,25,origin)

[Mücahit Gürbüz]

Thank you my friend :) it worked as I wanted.