Find holes and gaps in .stl files
37 visualizaciones (últimos 30 días)
Mostrar comentarios más antiguos
Eduardo
el 2 de Feb. de 2012
Comentada: mahmoud elmesery
el 24 de Mayo de 2021
Hi,
I need to find gaps and holes in a stl file. I don´t know if there´s a function developed that can help me. I started to work with MATLAB recently and i´m finding some dificulties. I found 2 ways of doing this, each triangle should have 3 adjacent triangles or each edge must have 2 triangles in common. Hope someone could give a hand. Thank´s.
Eduardo G.
3 comentarios
agdfg sdgfdg
el 10 de Dic. de 2013
[unqEdges, ~, edgeNos] = unique(edges,'rows'); | Error: Expression or statement is incorrect--possibly unbalanced (, {, or [. this the error i observed.
And i request you to suggest some other algorithms or codes for STL File Correction.
Respuesta aceptada
Sven
el 3 de Feb. de 2012
Hi Eduardo,
Firstly you need to read the .stl file in as faces and vertices. I'll presume you've already got that done (as Anton points out, stlread is available here http://www.mathworks.com/matlabcentral/fileexchange/22409-stl-file-reader).
Next, as you wrote: each edge must have 2 triangles in common... I think this is a good start. Here's some code that will make a test faces/vertices mesh, then determine such a thing:
% MAKE a face/vertices structure
tmpvol = zeros(20,20,20); % Empty voxel volume
tmpvol(8:12,8:12,5:15) = 1; % Turn some voxels on
fv = isosurface(tmpvol, 0.99);
% REMOVE a face
fv.faces(30,:) = []; % Remove a face!
% TEST for gaps or holes
edges = sort(cat(1, fv.faces(:,1:2), fv.faces(:,2:3), fv.faces(:,[3 1])),2);
[unqEdges, ~, edgeNos] = unique(edges,'rows');
if size(edges,1) == size(unqEdges,1)*2
% Every edge is used twice... consistent with a closed manifold mesh
disp('No problem!')
else
badEdgesMask = hist(edgeNos, 1:max(edgeNos))~=2;
badEdgeNos = edgeNos(badEdgesMask);
badNodeNos = edges(badEdgeNos,:);
badFaceNos = find(sum(ismember(fv.faces, badNodeNos),2)>=2);
end
Does this answer the question for you?
2 comentarios
Más respuestas (3)
Eduardo
el 26 de Feb. de 2012
2 comentarios
Sven
el 29 de Feb. de 2012
If you mean that the variable badEdgesMask only contains ones and zeros, then you need to realise that it's using logical indexing... if you're sure there's a problem, make a small example (such as the one I made) and show how it's not working.
Ver también
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!