← All tutorials // 34 Reduce mesh size

Simplify the mesh.

Merge the flat triangles you don't need and shrink the file your slicer has to chew through. Preview exactly what you'd lose in orange before you commit, scope it to a marked patch, or save it all for export.

// What it does

An edge-collapse decimator driven by a flatness threshold. It merges neighbouring triangles whose shared edge is flatter than the threshold, dropping the triangle count to shrink the export and lighten your slicer's load. Sharp creases, region borders, your colour edges and the silhouette are pinned, so detail survives. Preview only highlights — in orange — which triangles would collapse, without removing any. Simplify now commits the merge.

// When to use it
  • Shrinking a heavy mesh that's bogging down the painter or your slicer.
  • Tuning the flatness threshold before committing the merge.
  • Sanity-checking that the simplifier targets flat areas (chest plates, plinth tops) and not your detailed regions (faces, runes).
  • Doing a quick 'how aggressive can I be?' exploration.
// How to use it
  1. Export tab → Simplify. The Flatness threshold defaults to 2°.
  2. Click Preview only. An orange tint covers the triangles that would collapse — nothing is removed.
  3. Drag the threshold slider — the preview updates live. Higher is more aggressive; ≤1° is safely lossless.
  4. Click Simplify now to commit the merge. (Preview only is a toggle — click it again to clear the overlay without committing.)
// Scope it to a marked area

Mark first and Simplify only touches what you marked. Drag over a patch with the Mark tool, then run Simplify — only edges with both faces inside the marked area collapse, and everything outside keeps every triangle. Handy for flattening a big plinth or backplate while a detailed figure stays untouched. The orange preview respects the mark too, so you see exactly what's in scope.

// Simplify at export only

Want a light file but a hi-res mesh to keep painting? Tick Simplify at export only. Your working model stays full-resolution on screen — the decimation is applied only to the copy written into the 3MF when you export. Set the threshold, leave the toggle on, and export: the saved file is lighter while nothing on your canvas changes.

// Tips
  • ≤1° is safely lossless. Low angles only merge near-flat neighbours. Crank it higher for a smaller file, but watch the orange preview so you don't flatten detail you meant to keep.
  • Nothing collapsed? If you get 'no collapse found', the threshold is too low for this mesh — raise it until the preview lights up.
// Related tutorials
// 18

Mark area

Mark a patch first and Simplify only touches what you marked.

 // 22

Clean speckles

Repaint stray flecks into the colour around them.

 // 31

Export 3MF

Where 'Simplify at export only' lands — a lighter file your slicer reads.

Try simplify on the demo robot.

Open the painter and have a play.

Open the painter →