Architectural_Design_with_SketchUp

Chapter 5 Rendering in SketchUp
There are a few ways to fix this problem. Depending on the situation you are dealing with,
you might need to combine some of these. Figure 5.56 illustrates three common approaches
in SketchUp: spotlight, light-emitting face, and IES light.
Figure 5.56: Three methods to create recessed lights (left: spotlight; middle: light-emitting face; right: IES light)
The spotlight approach is similar to the one we used previously, with the main difference being
that this time we modeled the recessed light as a true recessed can. This allows us to use the internal
walls of the light fixture to capture light and therefore render the light source as an overexposed
circle. The important property to change when using this approach is the falloff angle value,
which must be large enough to include the side walls of the recessed fixture (e.g., 90 degrees).
The second approach, which uses a light-emitting face (a triangle, in this case), will be
discussed in more detail in the next sections. Basically, it uses a SketchUp face and applies a
light-emitting material to it. This approach has the benefit that we can control the size of the
light source simply by modifying the size of the face. If you want to use this approach, make
sure you use the simplest face possible. Remember that a triangle is exported to your rendering
application as one face, while a circle has many more faces (which increases rendering
time). It is also not as easy as with the other two approaches to tilt the spotlight (e.g., toward
a picture on the wall).
The third method uses an IES light that contains a certain amount of horizontal light spread
in addition to the downlight behavior (the same IES file used in the right image in Figure 5.57).
The benefit of using this approach is that the IES light very likely reproduces the wall reflections
of a true recessed light much better than either of the other two. Figure 5.57 shows a comparison
of all three approaches—note the double-arc light-beam projection with the IES light.
Figure 5.57: Rendered potlights from Figure 5.56
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