STL to solid

[Anonymous]

We have talked before... let me give you all the details and please let me know if this can be done.... I have fusion 360.. mesh mixer and remake.. also Modo (not your product but)... I am reverse engineering a part.. I have scanned it into a file with a 3D scanner.. it has 3,300,000 approx. faces or triangles the part is about 18 X 12 X 2 inches.. I can send you the file if needed... what I would like to do is turn this into a solid so I can reengineer it... the main body is complex so to redesign it would be  difficult.. I would like to cut a couple of protrusions off...then add different protrusions onto the main body .. I will also need to drill some new holes in the main body.. this cannot be done as a mesh.. (or am I missing something)... I have tried cutting off the protrusions in remake but I'm left with a hollow hole in the part... I have tried  to retropologize it to 700,000 triangles but no luck either.. . this would be so easy if I could convert it into a solid and then slice the unwanted parts off and slide on a new part and join it to the existing body.. I have done this with existing solid parts but this scanned mesh is throwing me for a loop... its the first time that I've used the scanner for this purpose.. am I barking up the wrong tree.. is there another program that will accomplish this... I've tried converting the STL file into OBJ. I can get them both it into fusion but can't do nothing with them.. I tried converting the STL to a DXF file but it won't load into fusion as a DXF.(even through the data door)  and its just to large or not right for fusion..  if you have any suggestions they will be appreciated immensely   Thanks  Tom..  

[paul.clauss]

Hi @Anonymous

Thanks for posting! It looks like you are running into some difficulties while trying to convert an imported mesh to a solid body in Fusion 360.

Fusion 360 does not yet support the import of point cloud data, so ReMake is a good place to start here. Once you generate a quad mesh out of ReMake, you should be able to bring it into Fusion and convert it to either a t-spline or b-rep body (by inserting the mesh as a base feature or working in direct modeling and using the Modify > Mesh to Brep tool). It sounds, however, like your mesh is a very large file, which will cause difficulties during the conversion from mesh to solid in Fusion.

A good rule of thumb in Fusion is to keep meshes under 10,000 facets - a lot fewer than you have in your mesh. There are some ways to reduce the facet count - I have shown some in the screencast linked here, and you could also try resetting the default quad engine in ReMake to reduce the mesh count while maintaining dimensional accuracy, as @innovatenate has shown in the screencast linked here. You will be looking for the block of text below in the remake.cfg file;

     <!-- export -->
                  <!-- 0 = InstandMeshes, 1 = ReForm(Windows only), 2 = Mudbox ->
                  <quadengine>2</quadengine>

Changing the "2" in the last line to a "1" will allow you to use the ReForm quads engine, which will help maintain the form of the mesh when exporting it in the Fusion Quads - OBJ format from ReMake.

With that said, reducing your very large mesh file to under 10,000 faces will undoubtedly lose quite a bit of mesh detail, so this may not be the best workflow for this part. I think that you are correct - the mesh model for this part may simply be too large to efficiently edit in Fusion.

To remove areas of the mesh body within Fusion, you may be able to use the Separate tool to split off parts of the mesh into separate mesh bodies, which could then be removed. You could then use the Make Closed Mesh tool to repair the hole in the original mesh body. I have shown a short example of this in the screencast below. This technique may help you de-feature the mesh body, but you would still need to convert to a solid body to add the new holes. Using the Separate tool to de-feature the mesh may help you reduce the number of mesh elements in the body, but it will be hard to reduce the mesh enough to convert it to a solid without losing model details due to the very large size of the original mesh.

If you'd like to attach the mesh file I am happy to have a look! Please let me know if you have any questions.