What does in the stlwrite command the optional argument SolidIndex exactly do?

Can anyone explain me how the SolidIndex argument works in the stlwrite command. I don't really understand the explanation for this issue in the respective documentation and still even don't have a rudimental clue for what it's good for...

Answer 1

[Chidvi Modala]

stlwrite(TR, filename) writes a triangulation TR to a binary STL file 'filename' in the order left to right. For example

P = [2.5 8.0; 6.5 8.0; 2.5 5.0; 6.5 5.0; 1.0 6.5; 8.0 6.5];
T = [5 3 1; 3 2 1; 3 4 2; 4 6 2];
TR = triangulation(T,P);
triplot(TR)
stlwrite(TR,'tritext.stl','text')

You can execute the above code, and open tritext.stl file. You can see that the order in which the triangles are defined in tritext.stl is from left to right as shown below

You can use 'SolidIndex' name-value pair to include a vector of identification.

stlwrite(TR,'tritext.stl','text','SolidIndex',[1 4 3 2])

You can replace the last line of previous example code with the above piece of code, and open tritext.stl file. You can see that the order in which the triangles are defined, is based on the 'SolidIndex' as shown below

[Hikmet Eren]

Thank you very much for the clear answer!