Rendering in SketchUp

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Chapter 17: The Shadow Menu
Fig. 17.11: 
The Enter North Angle option is used to adjust the angle of the sun to 0. This flips the direc-
tion of light and shadows in comparison to direction in Fig. 17.10.
Working with Shadows
Displaying shadows in SketchUp is fun. Doing so makes even simple models come to life. 
However, the Shadows tool has some downsides. Detailed or large models, particularly models 
with 3D vegetation, can experience extreme performance degradation. There are specific times 
and ways to use Shadows to maintain computer performance and model efficiency. Here are 
some general rules you can follow when you’re using shadows for normal modeling and setting 
light for rendering.
Shadows Off
Do not work with Shadows turned on. Do not model, insert components, or take similar actions 
with Shadows on. Performing tasks with Shadows on will slow performance even with small 
models, and working is almost impossible with large ones.
Don’t Move
Once Shadows are turned on, especially in large models and particularly those with 3D 
vegetation, don’t move. Once you pan, orbit, or zoom, SketchUp will turn off the Shadows, 
move to the new location, and have to reprocess the shadows again to make them visible.
Don’t Save
Do not save your models with Shadows turned on. Doing so makes it take exponentially longer 
for the model to open; doing so for large models can cause crashes.

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Part 4: Setting Light with Shadows
Don’t Multitask
When waiting for Shadows to turn on or when they are on, switching to other programs, tasks, 
or browsers will cause SketchUp to reprocess the Shadows when switching back.
Using Shadows
The Shadows tool should be treated as a precision instrument. Timing is everything! Use 
Shadows only when you’re assessing or exporting views. Follow the previous rules when you’re 
performing either task.
Turn Shadows on to assess light for renderings and images when you have a specific camera 
view set. Assess the quality and the direction of the shadows; if needed, save it as a scene.
Turn Shadows on to export images when the view is set and you are exporting images from 
SketchUp. Turn the Shadows off before you move to the next scene or camera view.
Chapter 18 expands on the process of assessing light and shadow.