Architectural_Design_with_SketchUp

Architectural Design with SketchUp
Combining Lighting Scenarios (in Photo-Editing Software)
Various rendering packages nowadays have the ability to apply lighting scenarios once the
rendering is completed. The benefit of such an approach is that after just one rendering it
is possible to view a scene at different lighting stages—for example, with daylight, at night,
or with different artificial light sources enabled. You can easily use this technique to create
many different images from just one rendering.
Even if your rendering software does not provide this functionality, it is possible to simulate
changing light scenarios in Photoshop (or any other image-editing software). The steps are as follows:
1. Render the same scene with different light groups enabled for each rendering. The lefthand
image in Figure 5.61 shows the three base renderings with (1) only daylight, (2) only
the floor lights, and (3) only the downlights. It should be easy to disable lights individually
or in groups in your rendering software. If that doesn’t work, place all similar lights on
their own layer and then enable only the appropriate layer before you do the renderings.
Figure 5.61: Three renderings with different lights are combined in Photoshop using “screen”
layer blending
184
2. Load the rendered images into your photo-editing software’s layers (Figure 5.61 shows
this for Photoshop).
3. Apply the “screen” layer blending mode to all layers. This “adds” light for each pixel when
the individual layers become visible. You can also now adjust the opacity sliders for all
layers to adjust the intensity or visibility of each of the light groups.