Architectural_Design_with_SketchUp

Chapter 5 Rendering in SketchUp
These shortcomings can be remedied only by using photorealistic rendering software.
Fortunately for today’s SketchUp user, there are many options available—from free programs
to movie-quality (and expensive) software packages. The following sections present some
of these and introduce you to common techniques used to create high-quality photorealistic
renderings.
See Figure 5.4 for a comparison of the display styles that are possible in SketchUp without
a rendering software.
Figure 5.4: Comparison of different default SketchUp display styles (left to right: textured, x-ray, solid color,
conceptual, hidden line, wireframe)
Overview of Rendering Methods
Photorealistic rendering in SketchUp (or any 3D modeling software, for that matter) uses
a different approach from what we saw when we looked at SketchUp’s own styles. In the
case of styles, SketchUp uses your computer’s graphics card to “render”—or calculate—the
view appearance. In that process, the view and all visual features (such as custom linetypes)
are being created pixel by pixel by your graphics card at a rate that is faster than your eye
can perceive it being refreshed. As a reference, your monitor has a refresh rate of at least 60
hertz (60 screen updates per second).
Because SketchUp’s visual styles can be displayed at roughly the same frame rate that
your monitor uses, you can actually move around a model that has styles applied and view
or edit it in real time (this performance depends on the model complexity and style complexity,
as well as the graphics card and CPU quality, of course—the higher the demand on the
graphics card, the slower it can process the view and the more jagged any motion becomes).
Photorealistic rendering, on the other hand, has the capability to accurately estimate
material properties such as reflection as well as light properties such as colored lights or soft
shadows. This, however, comes at a computational cost. In most rendering software, these
computations are not performed by the graphics card but by the CPU (your computer’s “computational
heart”). Only the newest rendering software also processes some or all of these
135