FuMesh is the mesh editor I made for fixing 3D models and getting them ready to print. Version 0.3.0 is out for Mac, Windows and Linux, still as early access, and this one is about new tools rather than fixes: fifteen of them, each with a preview, one undo step and its own paragraph in the user guide.
The list came out of asking a simple question: when I’m working on a scan, what sends me to another program? Cutting along a line instead of a flat plane. A scanned mug handle that came back as two holes. Lining up two scans by hand when the automatic fit isn’t sure. Putting a logo on a part. Those gaps are what this version fills.
Early access. It works on my models and prints, but expect rough edges, and things may change between versions. Keep a copy of your original files, and don’t rely on it for anything important yet.
Cut along a line you draw
The Cut tool has a new Freehand mode. Drag a line over the model and the cut follows it straight through, exactly as you see it on screen. An open line is extended to the edges of the view and you keep its left or right side; end the line near its start and it becomes a loop, so you can cut out just the piece inside it. A jagged scan edge, or a part that has to come off along a curve, is one stroke now instead of a series of plane cuts. The cut is left open on purpose, and Find holes closes it when you want it closed.
Repairs a scan actually needs
Bridge two holes is for handles, cables and rings: a scan often gives you two openings where there used to be a tunnel, and filling them would close the wrong thing. Choose the two holes and FuMesh builds a tube between them, running through the part or round the outside, whichever doesn’t cut through the surface. The tube follows the two rims’ shapes and blends from one to the other, so a round hole and a slot still meet cleanly.
Remove spikes deals with the lone points that scanners leave sticking out of a surface. Smooth would blur the whole area; this finds the vertices that stick out alone and pulls just those back, so edges and corners stay sharp. The spikes are shown in red before anything changes, and a sensitivity slider decides how far a point has to stick out to count.
Two smaller ones in the same spirit: with triangles selected, Find holes can list only the holes that selection touches, which matters on a scan with hundreds of them, and Clip view hides one side of a plane so you can look inside a hollowed part or check a seam from within without cutting anything.
Sculpting, symmetric and sharper
Mirror across applies every stroke on both sides of a plane, so a face or a figure stays symmetric while you work. The mesh itself doesn’t have to be symmetric; the brush simply works twice.
Three new brushes join Smooth, Move, Flatten and Inflate. Pinch pulls the surface together along itself, which sharpens an edge a scan rounded off. Crease pinches and sinks a groove at the same time. Clay builds material up in layers: each stroke raises the surface by a set amount under the brush, with a soft rim, and never more within the stroke, so you can shape something stroke by stroke, or take a layer away with Subtract.
And there is a painted Mask: brush over the places you want left alone and the other brushes stop there, fading in at the mask’s edge. The mask belongs to the object and survives a saved project.
Several objects at once
You can now select several objects in the Scene panel, with Ctrl-click (⌘-click on a Mac) or Shift-click, or by clicking them in the view with the same keys. The active one is drawn brighter and is what the single-object tools work on; the rest come along for the new multi-object commands.
Merge selected objects joins them into one without a Boolean, which is right for parts that don’t touch, or when a Boolean refuses an open mesh. Nothing is welded, so Split into parts takes them apart again exactly. Align objects lines them up with the active one along an axis, spaces three or more evenly, or arranges them on the bed in a grid with the gap you set, which is a nice thing to have before exporting a whole plate as 3MF.
Lining up two scans by hand
Auto-Fit lines up two overlapping scans on its own, and says so honestly when it isn’t sure, for example when the shape is symmetric and another position fits just as well. Align by points is the manual way for those cases: click a point on the fixed object, then the matching point on the moving one, three or more pairs, and one moves onto the other. The pairs are numbered in the view, and afterwards a table shows how far each pair still is apart, so a mis-click stands out and can be removed. From there you can hand the pair to Auto-Fit to polish the result.
Labels that land on the surface
Text as a solid was already there; now it can be placed where you click. Choose Place on a surface in the Add text dialog, click the model, and the text lands there standing along the surface and reading the way you look at it, sunk in a little. Choose Emboss or Engrave and the Combine panel opens with the union or difference already set up and previewed, so a label is one click plus Apply. If the model isn’t a closed solid yet, the label stays placed and the panel says what to fix first.
The same works for drawings: Add outline takes an SVG file, a logo or a symbol made of closed shapes, and extrudes it the same way. Rings keep their holes, and Mirror flips it for engraving into an underside.
And Subdivide
A coarse STL can’t be sculpted smoothly because there are too few triangles to move. Subdivide adds them, four of every one per level, either keeping the shape exactly or rounding it. With triangles selected it subdivides only those and splits the neighbouring triangles to match, so the mesh stays watertight.
How it was built
As before, the code was written with Claude, this time from a written design that I approved before anything was built, one tool at a time with the tests written first. The packages passed the built-in self-test on each platform, including all 23 tool panels, and the Mac version is signed and notarized. The Windows builds are still unsigned, so Windows asks once before the first start.
It works offline, needs no account and sends nothing anywhere. It’s free and open source under the GPL. No warranty, no support promise; if it’s useful to you too, good.
For the Mac, Windows and Linux. Get it here!