Design Nomenclature / Digital Model Making
Decimate
Also called polygon reduction, poly reduction, mesh simplification
Reducing triangle count by collapsing edges in order of how little each collapse changes the surface, usually by a quadric error metric. Silhouette is preserved; layout is not. The output is an irregular triangle soup that deforms badly and unwraps worse — correct for a static prop, wrong for anything that moves.
In practice
“Decimate it” often means “make this scan usable”, which is a retopology job. Decimation is for things that will never be rigged.
Not to be confused with
- RetopologyBuilding a new, deliberately laid-out mesh over an existing surface, by hand or with guided automation. The goal is not fewer polygons; it is edge flow that deforms correctly, loops that follow the anatomy or the feature lines, and a quad-dominant cage that subdivides cleanly. Detail returns by baking.
- RemeshReplacing a mesh's topology wholesale with a new, evenly distributed one approximating the same surface. Voxel remeshers rasterize to a grid and re-extract, guaranteeing watertightness and losing everything below cell size; quad remeshers fit a quad field, optionally guided, and get closer to a layout someone could work with.
- LODA set of alternative representations of one asset at decreasing complexity, swapped by screen coverage or distance so the renderer spends detail where it can be seen. Authored deliberately, since silhouette and material must survive the switch. The transition is the hard part — a visible pop is a failed LOD.