Getting started

From download to a repaired, remeshed and verified part in a few commands.

1. Download and install

Get the archive for your system from the download page, check it against SHA256SUMS, unpack it and put betti on your PATH:

sha256sum -c SHA256SUMS --ignore-missing
tar xzf betti-v0.20.0-linux-amd64.tar.gz
install -m 755 betti-v0.20.0-linux-amd64/betti ~/.local/bin/betti
betti version

On Windows, unzip the archive and put betti.exe in a folder listed in PATH. On macOS, if the system refuses to open a downloaded program, allow it under System Settings, Privacy & Security.

2. Find your way

betti help              # every command, by module
betti fix               # a module's commands
betti help fix repair   # a command's usage, flags and examples

Core commands are at the top level, as in betti info; every other module's commands are under its name, as in betti mesh remesh. The docs carry the same text as the built-in help.

3. Sign in

Core commands (info, box, verify, convert, run) are free and need no sign-in. For the other modules, sign in and ask for the ones you need:

betti access login
betti access
betti access request fix mesh -note "preparing parts for CFD"

See access and licensing for more.

4. First commands

See what a file is: its size, parts, holes, crossings and element quality.

betti info part.stl

Repair it into closed, outward-facing solids, then remesh it into even triangles of 1% of its size:

betti fix repair part.stl fixed.obj
betti mesh remesh -size 1% fixed.obj even.obj

Check the result against the input: distances between them, sharp edges kept, and the same topology.

betti verify part.stl even.obj

Have a STEP model? Check it, heal it, or mesh it watertight with each triangle tagged by its CAD face:

betti cad check part.step
betti cad heal part.step healed.step
betti cad mesh part.step part.vtu -size 2

Every command takes -json to print its result as JSON, -q to print nothing but errors, and -v to show its stages and their times. Ctrl-C stops a command within moments, and a file is written whole or not at all.

5. Chain steps with run

betti run runs steps one after another on a mesh kept in memory and writes the last one's mesh. Steps are commands with their flags, separated by +:

betti run part.stl out.obj fix repair + mesh remesh -size 1% + shape defeature -size 2

Put steps in a recipe file, one to a line, with # starting a comment, and run it with -recipe. A save step writes the mesh as it is at that point:

# clean-for-print.txt
fix repair
save repaired.obj
mesh remesh -size 1%
additive place

betti run part.stl ready.3mf -recipe clean-for-print.txt

The steps a chain can take are listed on the run page.

6. File formats

Formats are chosen by extension. STL is read but not written: its single precision can make faces cross. Quads are kept in OBJ, OFF and PLY. Particle and sphere commands write their own formats for SPH and DEM codes; see particles fill, particles clump and particles spheres.

7. Lengths

Lengths are absolute, in the file's units, or a percentage of the part's bounding-box diagonal:

betti mesh remesh -size 2 part.stl even.obj     # edges about 2 long
betti mesh remesh -size 1% part.stl even.obj    # edges about 1% of the part's diagonal

Percentages make a command work the same on parts of any size and unit.