Mesh to brep results: sometimes solid body, sometimes mesh body. Why?

[JayLoomis]

Hello,

I have imported 2 OBJ files that I want to modify as solid bodies.

I'm using "convert mesh to brep" and I get different results for each OBJ: for one I get a "solid body" (yay!), and for the other I get a "mesh body" (now what do I do?!).

Why does this happen? How can I convert the mesh body to a solid body?

See attached screenshots. The first "mesh to brep" shows the resulting "mesh body," and the second "mesh to brep" shows the resulting "solid body."

Thank you for your time and consideration!

Jay

[TrippyLighting · Accepted solution]

Importing triangulated meshes for modifications is generally not such a great idea but to answer your question,

not all meshes are created equally. If they don't enclose a volume watertight, then they convert into a surface body.

So you'll have to find he hole, patch it and then stitch it into a solid body.

[JayLoomis · Accepted solution]

Hi Peter,

Thank you! Got it.

"Importing triangulated meshes for modifications is generally not such a great idea..."

In general, if I have an OBJ file, what's the best workflow to import it and make modifications to it as a solid body?

Thank you for your time and help!

Regards,

Jay

[TrippyLighting · Accepted solution]

That depends on what form of mesh is contained in the .obj file.

A quad mesh can be converted into a T-Spline and then into a BRep (Solid Body, or surface).

A triangulated mesh is not so easy to work with and depending on the size  and nature of the mesh, whether it is more mechanical and prismatic, or more organic and irregular. The latter can in many cases be addressed with tools outside of Fusion 360 (and then be brought back into Fusion 360).  Mechanical stuff is often better re-designed from scratch with the Fusion 360 native tools using the mesh as a visual guide and for measurements.