Page 237 - Enhancing CAD Drawings with Photoshop

4386.book Page 221 Monday, November 15, 2004 3:27 PM

Chapter 7

Creative Compositing

You will use both Adobe Photoshop and Autodesk VIZ in the compositing techniques presented in
this chapter. In this context, compositing is the art of blending and enhancing images rendered in VIZ
within Photoshop.
As you may know, one of the liabilities of solely using VIZ to create computer-generated imagery
(CGI) is the huge amount of time usually required to calculate photo-realistic renderings. Compositing
is a technique that speeds up this process by leveraging the power of Photoshop. Instead of spending
time in VIZ designing realistic materials, simulating real-world light sources, and waiting for a
lengthy rendering calculation, Photoshop adds real-time realism to basic 2D imagery output from VIZ.
The compositing process begins in VIZ, where we’ll prepare a 3D model for rendering. Each object
is separately matted and rendered in VIZ with an alpha channel to preserve the object boundaries in
the images. This series of rendered images is then integrated in Photoshop into a composite whole.
In the transfer, each VIZ object becomes a layer in Photoshop, and the alpha channels become layer
masks.
To gain an understanding of how compositing works, you’ll step through a high-rise building
tutorial that shows you how to manually transfer objects from VIZ to masked layers in Photoshop.
You’ll save time processing the remaining objects in the scene by using MAXScript and an action that
automate the transfer from VIZ into Photoshop.
Once the project is assembled in Photoshop, you’ll add realism with many of the same layer style
effect techniques presented in Chapters 5 and 6, plus you’ll explore new creative compositing tech-
niques. This chapter’s topics include the following:
◆ Rendering in Autodesk VIZ
◆ Compositing in Photoshop
◆ Applying Effects to Masked Layers

◆ Working with the Environment
◆ Making Adjustments with Clipping Groups
◆ Adding to the Composite

Rendering in Autodesk VIZ

You will start the high-rise building tutorial in Autodesk VIZ 2005. A free trial version of Autodesk
VIZ 2005 is available at www.autodesk.com. Install Autodesk VIZ 2005 on your computer even if you
are accustomed to using other 3D software, because the techniques and automation presented in this