Page 290 - Enhancing CAD Drawings with Photoshop

4386.book Page 274 Monday, November 15, 2004 3:27 PM

274 CHAPTER 8 ILLUSTRATING ARCHITECTURE

Figure 8.19
The Zdepth channel

13. Rename the Alpha 2 channel Zdepth. Hereafter you’ll be able to select this channel by pressing
Ctrl+7 without having to select the Channels palette.

14. Press Ctrl+D to deselect. Then press Ctrl+~ to select the RGB channels (see Figure 8.20).
15. Click the Layers palette. Note that no new layers have been created while you have been add-
ing data to the Channels palette. Press Ctrl+S to save your work. If you’re going to continue
working through the following sections, you can leave this file open for now.

Figure 8.20
The Channels Palette

You’ll be using both the ObjectID and Normal channels to make selections that will be converted
to painting masks. The alpha channel provides the outline of all the structures, so it is always useful
for masking a background image. You can optionally use the Zdepth channel to create a 3D fog that
gets thicker in the distance.