Subdivision Surface

Subdivision surface splits every face into four and smooths the result. You shape a simple cage; the tool generates the smooth surface from it.

Drag a model to turn it.

The cageA plain cube: 6 faces. This is the mesh you edit.
1 level24 faces. Each face became four, and every point moved toward a smooth shape.
2 levels96 faces. The cube is already close to round.
3 levels384 faces. Each level costs four times the faces of the last.
Editing the cageMove one cage vertex and the smooth surface follows, without touching its hundreds of faces.
Support loopsLoops cut close to the edges keep them tight after subdividing: flat sides, crisp but rounded corners.
Some edges sharpSupport loops only near the top and bottom keep those rims hard while the sides round off.

In your tool

  1. Add a subdivision surface modifier (or turn on smooth preview).
  2. Set a low level for the viewport and a higher one for rendering.
  3. Add support loops or crease edges that should stay sharp.