how i find intersection point between 3d stl object and a line

i have a face uploaded as an stl file which is made up of faces and matrices i have a line passing through the surface i want to find the point where the line and surface intersects

[jabrie]

Did you find an efficient approach to solve this problem? I am also working with stl files (triangle meshes). But testing millions of 3D triangles for intersection with a line would not be efficient enough.

[Muhamad Amirulfaris Abdullah]

may i know how you create the stl file?

[Joseph]

In case anyone comes across this in the future. You can download stl and other model files from GrabCAD, and then importing STL files into MATLAB can be done through:

https://www.mathworks.com/matlabcentral/fileexchange/22409-stl-file-reader

https://www.mathworks.com/matlabcentral/fileexchange/51200-stltools

https://www.mathworks.com/matlabcentral/fileexchange/30923-fast-stl-import-function

https://www.mathworks.com/matlabcentral/fileexchange/29906-binary-stl-file-reader

[DGM]

Since R2018b, MATLAB has built-in STL tools. You don't need to download anything.

stlread

stlwrite

For legacy versions needing third-party tools, I'd strongly recommend these tools over other FEX tools. This explains why.

If you use #22409 or #29906 in a modern installation, you will shadow the inbuilt tools and likely cause problems for yourself unless you rename them. FEX #30923 has significant bugs. #51200 is good, but is superceded completely by #182013.

Answer 1

[deru jian]

STL approximate the outer surface of the 3D model by a number of connected triangles, so you could take a look at the ray/triangle intersection algorithms, that may help you.

Following are some ray/triangle Intersection functions:

https://www.mathworks.com/matlabcentral/fileexchange/25058-ray-triangle-intersection

https://www.mathworks.com/matlabcentral/fileexchange/33073-triangle-ray-intersection