MATLAB: How to use a dynamic name as a node in VRML

Question

Hello everybody!

The situation: I would like to create several nodes part_1, part_2,…, part_n with shape_1, shape_2,…, shape_n within a root in VRML. To do so, I could simply write:

pipe=vrworld('');
open(pipe);
vrnode(pipe,'part_1','Transform');
vrnode(pipe.part_1,'children','shape_1','Shape');
vrnode(pipe,'part_2','Transform');
vrnode(pipe.part_2,'children','shape_2','Shape');
...
vrnode(pipe,'part_n','Transform');
vrnode(pipe.part_n,'children','shape_n','Shape');

As you see, this requires me to type the commands manually n times 🙁

Is it possible create a loop that keeps doing this for me?

Something like this?

for i=1:n
a=['part_' num2str(i)];
b=['shape_' num2str(i)];
vrnode(pipe,a,'Transform');
vrnode(pipe.a,'children',b,'Shape');
end

Unfortunately the last command before the end causes problems

Error using vrnode (line 92)
Node 'a' not found.

Any suggestions?

Thanks a lot!

Regards Fred

Answer 1

Hello everybody! I figured out how to solve the problem :)

It was explained here :

http://blogs.mathworks.com/pick/2008/08/20/advanced-matlab-dynamic-field-names/

If someone is having the same problem, here comes the solution:

for i=1:n
a=['part_' num2str(i)];
b=['shape_' num2str(i)];
vrnode(pipe,a,'Transform');
vrnode(pipe.(a),'children',b,'Shape');
end

The brackets are needed to read the variable a :)

Regards Fred