A contextual menu will appear at the top of your viewport. Type in your desired Offset distance (e.g., 20mm or 0.5 inches) and press Enter.
Best practices
For Trimble SketchUp users, the native tools do not offer an automated way to round edges across complex 3D geometry. This is where the legendary extension becomes an indispensable asset for your workflow. Round Corner Extension Sketchup Free Download
Creating these rounded edges manually—drawing arcs, extruding, and erasing faces—can be tedious and time-consuming. That’s where the comes in. A contextual menu will appear at the top of your viewport