Meta Ball - Page 12

The final stop in our descent into cheap and easy shortcuts (everyone uses them) is the meta ball. The idea of the meta ball is that you place a bunch of spheres and then let the meta ball tool sort-of morph them all together, like the liquid metal guy in that Terminator movie. We are going to make a hand to go with our breakfast scene, to pick up the spoon, coffee cup, milk jar, toast. (The hand will probably also poke at the eggs to see if they are done — I don't know.)

1. The first thing we need to do is import a background image of a hand. Hands are hard to draw, and even harder to model in 3D space. Using a 2D image as a reference will give us a good head start. In the options menu for the top view, select Set Backdrop. In the dialog that pops up, select Load Backdrop and load handTrace. jpg from the examples folder on the CD. Accept the default parameters. You should get something like Figure 20-13.

2. Next start drawing spheres. Fill in the outline of the hand, putting elongated spheres where long bones go and rounder spheres where joints go. Your scene should look something like Figure 20- 14.

3. Once you are satisfied with the quality of your hand parts, select everything (CTRL-A) and use the meta ball tool. This tool is in the extensions palette, on the Commands tab. This is one place where the parameters on the object palette are especially important. Adjust the slider to your liking. Figure 20-15 shows my final hand.

Using meta ball as a modeling method obviously has limitations. The first thing you will notice, especially if you have a slow machine, is that the complexity of this model is off the charts. My hand came out to about 14,000 polygons. A good professional 3D artist could easily make an expressive hand that gives you the impression of life with fewer than 1000 polygons. Since every polygon is considered when you render a model or scene, the more polygons you have, the longer rendering will take.

The other big drawback is that, like any modeling technique that does not operate directly on the polygon vertices or points on a Bézier surface, you don't really have much control over the shape. We did get a serviceable hand model from the exercise, which is no small feat for your first foray into 3D, but at the expense of efficiency and control. Use tools like this moderately.

Final Thoughts on Strata 3D

Strata 3D is the best tool I've seen to get started in 3D. It combines a sensible, easy-to-learn interface with a no-risk cost at entry level and amazing power. In addition, there is a wealth of information online, from free textures and models to tutorials, discussions, and galleries of work. A good place to start is the online Strata Manual, which can be found at http://works.3d.com/onlinemanuals/index.html.

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