How to write axes on an imported mesh

Hello everyone,

I need help on a specific topic on Matlab.

I need to import on Matlab a meshed sphera created in Rhino7 and to insert in Matlab an axis passing through that sphera.

How can I insert the axis?

Thank you in advance

[dpb]

Can you show/attach illustration/code/datafiles that we can see and touch what you're dealing with?

In MATLAB, the axes is an object into which objects are placed and are children of; not the other way 'round; you don't place an axes onto an object; there are no graphics that aren't an axes in a figure.

So, to display this external object in the beginning it would have to have displayed in an axes already -- unless, of course, it's some external object of its own that MATLAB has no way to import and so you're stuck at that point.

Anyways, need to start off with showing us what this thing is and from whence it came...

[Geraldina Berti]

[Geraldina Berti]

[dpb]

But we need code as text (paste and format with the "CODE" button (the LH icon in section that's to represent indented code lines) and then attach the image file with the paperclip in "INSERT" section.

[Geraldina Berti]

to make you understand my statement, I have to put this meshed object on matlab and I need to define and axis passing through its center and another axis (parallel to the first one) at a certain distance; later on I'll have to give the nodes a certain angular velocity with respect to those axis in order to make the body rotate.

[Geraldina Berti]

Sfera=fullfile(toolboxdir('lidar'),'lidardata', ...
    'surfaceMesh','Sfera.stl');
mesh=readSurfaceMesh(Sfera)
surfaceMeshShow(mesh)

It's not possible to attach a .stl file

[dpb]

You can zip it first...or save the resulting mesh object you read as a .mat file and attach it. "More than one way to skin a cat..." :)

[Geraldina Berti]

Here it is!

[dpb]

unzip('Analisi Matlab.zip')
mesh=readSurfaceMesh('Analisi Matlab')

readSurfaceMesh requires Lidar Toolbox.

surfaceMeshShow(mesh)

Looks as though the Lidar TB isn't available to the Answers forum interactive session....

[Geraldina Berti]

Maybe you need this folder too

Answer 1

[Fabio Freschi]

You can use quiver3. In the example below I plot the 3 coordinate axes, you can modify accoridng to your vectors

clear variables, close all

% unzip
unzip('Sfera.zip');

% load stl file
tri = stlread('Sfera.stl');

% plot triangulation
figure, axis equal, hold on
view([1 1 1])
trisurf(tri,'FaceAlpha',0.5);

% plot three coordinate axes
vx = [1 0 0];
vy = [0 1 0];
vz = [0 0 1];
quiver3([0 0 0],[0 0 0],[0 0 0],...   % starting points
    [vx(1) vy(1) vz(1)],[vx(2) vy(2) vz(2)],[vx(3) vy(3) vz(3)],...  % vectors
    10,...      % scaling
    'filled','LineWidth',3);  % appearance params