I am facing an issue while combining two stl.

I have two 3D geometries along with their associated nodes and faces. I want to combine these two STL geometries by merging their nodes and faces into single geometry.

Answer 1

[Gayatri]

Hi Vijay,

Below is a MATLAB script that demonstrates how to combine two STL into one single geometry:

% Read the STL files
shape1 = stlread('file1.stl');
shape2 = stlread('file2.stl'); 

% Extract nodes and faces from both geometries
vertices1 = shape1.Points; 
faces1 = shape1.ConnectivityList;

vertices2 = shape2.Points; 
faces2 = shape2.ConnectivityList; 

% Adjust face indices for the second geometry by adding the number of vertices from the first geometry to the second's face indices
updatedFaces2 = faces2 + size(vertices1, 1);

% Combine the vertices and faces
mergedVertices = [vertices1; vertices2];
mergedFaces = [faces1; updatedFaces2]; 

% Create a new triangulation object for the merged geometry
mergedGeometry = triangulation(mergedFaces, mergedVertices);

% Write the merged geometry to a new STL file
stlwrite(mergedGeometry, 'merged_geometry.stl');

Please refer the below documentations for 'stlread' and 'stlwrite' functions:

• https://www.mathworks.com/help/matlab/ref/stlread.html
• https://www.mathworks.com/help/matlab/ref/stlwrite.html

Answer 2

[DGM]

See also:

https://www.mathworks.com/matlabcentral/answers/2131056-combine-two-stl-into-one#answer_1568109

This answer uses convenience funtions to do the concatenation, and it will automatically clean up redundant vertices. It works with triangulation objects and other formats.