You can increase or decrease subdivision iterations (typically up to level 4) to control the smoothness of your model without permanently altering the base geometry.
This feature allows you to select specific edges or vertices to "crease," preventing them from being smoothed. This is vital for maintaining sharp details on an otherwise organic form, such as a sharp edge on a piece of upholstered furniture. Pricing and License Key Information Sketchup Subd License Key
It is optimized for "quads" (four-sided faces). While SketchUp natively uses triangles for non-planar faces, SUbD works seamlessly with QuadFace Tools , a free companion extension that helps manage quad topology. SUbD works seamlessly with QuadFace Tools