Soften Edges Dialog Box

SketchUp's edges can be softened and smoothed to achieve a real-world appearance. Edges are automatically hidden when softened. Softened edges can also be smoothed rendering the adjoining faces with a smooth tonal gradient. The following series of images contains a column (lower part of each image) that is first softened (middle column) and then smoothed (right-most column).

Note - Softened edges are hidden automatically (but still exist in your model). Edges that are currently not visible will be displayed, along with any explicitly hidden geometry, when you enable the Hidden Geometry menu item on the View menu.

Tip - Triple-click on geometry to ensure you have hidden and unhidden geometry selected before performing a soften or smooth operation.

The Soften Edges dialog box allows you to automatically apply or remove softness and smoothing effects to the edges in your model. Activate the Soften Edges dialog box from the Window menu.

Tip - There are a several components to achieving a desired result using soften and smoothing effects. Namely, detailed geometry require additional facets (such as a column having many small sides) to achieve a clean soften or smooth effect. However, additional detail can affect the computer's performance. Conversely, adding detail to portions of a model that will be seen at a distance is likely a waste of the computer's resources. A good strategy for creating useful models is to try to use the least amount of geometry in conjunction with soften or smoothing effect to achieve the desired result (whether it be a detailed close-up or a panoramic).

Soften Edges Options

SketchUp contains a few Soften Edges options allowing you to manipulate the use of softening within your model.

Note - Edges that are shared by three or more faces cannot be softened. The following image shows an edge shared by three faces.

Angle Between Normals

Use Angle Between Normals slider to set the maximum size of all angles that will be smoothed or softened. The higher the setting, the more angles you are likely to smooth or soften with a smooth or soften command. Consequently, the higher the setting the more performance might degrade.

Smooth Normals

Click on the Smooth Normals checkbox to smooth any edges, essentially spreading color and texture over edges, to make the edges appear smooth.

Soften Coplanar

Click on the Soften Coplaner checkbox to soften edges, essentially deleting edges, between coplanar surfaces.

Tip - Create a three dimensional multi-sided polygon (with more than 5 sides) and experiment with these options to become familiar with softening and smoothing models. For example, create a 6-sided polygon, expand the polygon using the Push/Pull Tool, select the entire 3D polygon, click on Smooth Normals, and move the Angle Between Normals to 61 degrees. Notice that each edge of the polygon looks smooth because the angle between each normal is 60 degrees and, therefore, can be smoothed. Now move the slider to 59 degrees. Notice that the sides no longer look smoothed because the Angle Between Normals only operates on angles below or equal to 59 degrees. Experiment further by turning on the Soften Coplaner option to see edges appear and disappear.