Error while using Surface Intersection function in a loop "Subscript indices must either be real positive integers or logicals"

Hi everybody, I am struggling with the last part of my Script. I attach here the error and the correlated part of the script.

Script:

 for ind1=1:length(Slicesurf)
   for ind2=1:(ncontour*2)
            [~, intersection] = SurfaceIntersection(Slicesurf(ind1),Htot(ind2));
            Infill(ind1,ind2).faces=intersection.faces;
            Infill(ind1,ind2).vertices=intersection.vertices;
            Infill(ind1,ind2).edges=intersection.edges;
    end
 end

the curious thing is that the loop goes well for a few rounds but then it stops and give me this error. ncontour and lenght(Slicesurf) are both real and positive. Slicesurf contains all surfaces parallel to xy plane and Htot contains 3D parabolas.

Error:

 "Subscript indices must either be real positive integers or logicals.
Error in SurfaceIntersection>TriangleIntersection3D_Moller (line 367)
a2 = lut(sign(du)*[9; 3; 1] + 14); % calculate the key and call the look-up table
Error in SurfaceIntersection (line 218)
      [intMatrix(tMsk), intSurface] = TriangleIntersection3D_Moller(...
Error in SurfaceIntersection_prova13 (line 166)
            [~, intersection] = SurfaceIntersection(Slicesurf(ind1),Htot(ind2));"

can someone help me? I am going crazy with this error!

Thanks a lot!

[Gian Marco Tassi]

https://www.mathworks.com/matlabcentral/fileexchange/48613-surface-intersection

this is the function SurfaceIntersection

[J P]

Hi, I am currently having the same issue, did you ever find a fix?

Answer 1

[James Tursa]

Often this is the result of having a variable with the same name as a MATLAB function you are using, so the variable is shadowing the MATLAB function. E.g., maybe you have inadvertently created a variable named "sign" and "du" is not an integer when you encounter sign(du).

[Gian Marco Tassi]

I don't have any variable called du or sign. I have checked it with whos command