Google SketchUp: The Missing Manual

Choosing Whether Faces and Edges Cast Shadows

You get to choose what entities in your model cast shadows. When SketchUp creates a new document, the settings are pretty good, but if you have special needs for a model, you can make changes. At the bottom of the Shadow Settings box, you see three checkboxes:

• On Faces. Usually you want this option turned on, so shadows appear on the faces in your model. That means any faces like walls and doors display shadows that happen to fall on them.

• On Ground. If you don't specifically create a ground plane for your model, SketchUp considers the horizontal plane at the level of the Origin the ground plane. When this checkbox is turned on, shadows appear on the ground plane. One time you want this option turned off is if you model your own terrain in SketchUp. In that case leave On Faces turned on. Then your shadows appear on the faces of the terrain.

• From Edges. Usually a single edge doesn't cast a shadow, and most of the time that works best. However, if you're using edges to represent something like a telephone line or thin cables like those in Figure 11-11, and want them to cast shadows, turn on the From Edges box.

Tip

Choosing the option to cast shadows From Edges puts a strain on any computer that lacks an extremely powerful graphics card. Sometimes this can stop your computer dead in its tracks while it makes calculations for all the shadows.