Subdivision Surface Modifier
Smooths a low-poly mesh by adding geometry
Also known as: Blender subdivision · Blender subsurf · Blender Ctrl 1 · Catmull-Clark Blender · Blender subdivision levels
Definition
The Subdivision Surface modifier smooths a mesh by splitting each face into smaller faces and rounding the shape, using the Catmull-Clark method. Low-poly meshes become smooth and organic, which is why it is the base of most character and product modeling. It has separate Levels Viewport and Render settings, so you can work with a light mesh and render with a smooth one. Ctrl+1 to Ctrl+5 add the modifier at that level.
In production
Model with mostly quads and clean edge flow, and add support loops or creases near edges that should stay sharp. Poles and n-gons give shading pinches, so keep them away from curved areas. For game assets, subdivision is used to build a high-poly for baking, not for the final low-poly. Keep the viewport level low on heavy scenes to avoid lag.