Rendering in SketchUp

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Chapter 23: Exterior Light
E
xterior lighting uses sunlight to illuminate a rendering. For exterior lighting, there are 
two general options: you can use the SketchUp Shadow menu or image-based lighting 
(IBL/HDRI). All IRPs support the SketchUp Shadow menu to set lighting; the Shadow menu 
is also referred to as the Physical Sky setting in the IRP. Some IRPs allow you to insert image-
based lighting photos to generate light.
This chapter reviews the various lighting settings found in the different IRPs. Specific light-
ing options are detailed in the IRP-specific exterior lighting chapters.
First Lighting Steps
When first you’re learning to render, use the SketchUp Shadow menu (Physical Sky) to set the 
lighting (Fig. 23.1, Fig. 23.2). Make sure you understand how to compose light for different 
scenes and settings as outlined in Chapter 17. Once you are familiar with the settings, 
experiment with HDRI images if they are available in the IRP you are using.
Fig. 23.1: 
Shadows set-
tings in a SketchUp model 
determine the lighting for 
the exterior rendering.
Exterior Light
ChaptEr
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Part 5: The Iterative Rendering Process
Fig. 23.2: 
This model rendered in Twilight Render duplicates the light settings from the SketchUp (model by John 
Palmer and Daniel Tal).
SketchUp Shadows
Most IRPs use the default Physical Sky setting of the SketchUp Shadow menu. For some IRPs, 
this is the only option. To learn how to best compose a scene using Physical Sky, make sure 
you’ve read Chapter 17 and Chapter 18 in Part 4.
Some IRPs have a setting called SketchUp Sky. It is identical to Physical Sky as it refer-
ences the SketchUp Shadow menu. Using this setting, the render engine will cast equal light 
throughout the render. It will not alter the color or amount of light based on the time and date. 
It references only the direction of sunlight in the scene.