Real World Versus the Digital World
Photographic miniatures have long been a staple of visual effects, using real-world materials to match the look of a full-sized object. The recent innovations in computer graphics imagery (CGI) has expanded the palette of the visual effects artist into realms that were previously impossible. Three-dimensional, or 3-D, computer graphics are created entirely in the “virtual” world using specialized 3-D software. Though the computer monitor, like the movie screen, is only a two-dimensional medium, geometric data is represented in a three-dimensional construct, using shadows, highlights, and perspective, among other aspects. But whether it's a plastic model on a stick or a computer-generated landscape, the basic steps remain the same.
Creating realistic miniatures is a true balance of art and technology. For decades, models were built from clay, metal, wood, rubber, or plastic. They not only had to look real, they often had to operate like the real thing. Propellers had to spin and lights had to blink and power lines had to blow up.
When purchasing a previously built 3-D model, be sure you're also buying the rights to use that model in your film. Models that replicate copyrighted objects such as the starship
Sometimes even the term “miniature” seems out of place when you consider that models such as the submarines in
Objects are pieced together from smaller objects, comparable to adding shapes of clay to one another. In their most basic form, the objects are cubes, spheres, cones, pyramids, and prisms.
Shapes are defined by the arrangement of
This is defined as the limit of an infinite refinement process. Basically, it means you can begin with a rather blocky shape made up of big subdivisions. You can divide those into smaller subdivisions, then smaller again, and so on. With each successive refinement, the surface of the object becomes smoother. But like polygons, the more subdivisions you have, the more computer power it will take.
An acronym for non-uniform rational B-spline, NURBS is a way of expressing complex curves in a standardized mathematical formula. This is important if you're the designer of a car or boat and you want the builders to get the shape just right, but you don't need to understand the math in order to use the NURBS function in most 3-D software. There are usually metaphorical tools to let you shape objects the way you want while the computer handles the number crunching.
Finessing Your Model
Once a model is built, the next step is to add texture, color, shading, transparency, reflectivity, specularity, or any of the seemingly endless list of characteristics that would make an object appear real. Many 3-D applications have built-in surfaces. To make the bumper of a car shine, for example, you only have to highlight the appropriate parts of the object and then select “chrome” from the preset choices. Once the basics are set, you may want to add scratches, dirt, or “rough spots” to add an extra layer of realism.
Building the model may also involve giving the object a