ProVideo Coalition.com: Creating Motion Graphics: Keyframes by Chris & Trish Meyer

These are the areas that I personally enjoy most about 3D. In most 2D applications, every object or layer is usually “lit” evenly, and any text or simple shapes you create default to perfectly smooth, even color. But that’s not what happens in the real world.

If you don’t have experience using real lights, virtual lighting can be one of the biggest challenges to learning a 3D program - but if you do, you’ll find 3D far more flexible than most lighting tricks available in 2D programs. By using lights, you have a much wider range of moods you can set by focusing on individual areas, or just “brushing” an object with light. The figure at right is an example of a simple, flat logo that has been made far more mysterious by focusing a pair of spotlights on relatively small regions of the semi-transparent letters.

Virtual lighting in 3D encourages artistic experimentation in setting moods, even on these three simple solid-colored letters. The “P” also has a slight bend deformation along its face, to allow the light to play off it in a more interesting fashion.

Most 3D objects default to the look of smooth, white plastic - not a big improvement over the solid colors in 2D programs. However, all 3D programs allow great latitude in how you “texture” the surface of your objects. You can either apply a texture map, which can be a still image or movie of the type of surface you want your object to have, or use a “shader” which automatically calculates building-block style textures, such as clouds, bricks, or surface grain. Both texture map libraries and shaders are available from third parties, akin to stock footage and plug-ins for 2D programs.

Avoid the temptation to use textures that resemble shiny gold or blobby day-glow psychedelics; they’re sure marks of a beginner. Quite often, I choose only a simple color for my objects, and then add a “bump” map which modulates and diffuses the light that hits the surface to make it look like it is rough or has a pattern. Another underused, understated trick is to manipulate what’s usually called the “diffuse value” of a surface, which decides how much light is absorbed or bounced back at various points across the surface. Applying a grime map or even a simple cloud shader, you can age a surface nicely for added realism. (For more on this technique, we particularly like the Surface Toolkit from dvGarage - it’s the first texture library we load up for every job.)

Modeling

Perhaps the scariest thing about learning 3D is learning how to build the objects that will populate your virtual worlds. Some dedicate their careers to the art of building 3D models. But even though knowing how to model is a definite plus, there are shortcuts.

A large amount of simple 3D consists of bringing in text or EPS outline art, and extruding it into 3D models. Fortunately, most programs have this ability built-in. If not, you can buy a plug-in or application that does this; Zaxwerks’ Invigorator Pro is one of the most popular for After Effects users, while their ProModeler is a stand-alone application for other users. Most 3D programs also make it easy to create primitive shapes, such as boxes and tubes.

A secret weapon to add to these is to learn your program’s deformation tools, which allow you to bend and warp your models. The letter “P” in the figure above shows a common trick of adding a slight bend to the surface of an object: light plays across it in far more interesting ways than perfectly flat objects. Some of these techniques were covered in a previous column.

And just as you can buy stock footage of shots too expensive or impractical to get yourself, several web sites act as clearing houses for 3D models, such as TurboSquid and 3D Cafe. Also don’t rule out hiring someone who has dedicated their career to the art of 3D modeling - this way, you end up with something custom, and most appropriate for your job.

Rendering

The biggest gotcha of 3D is the time it takes to render a scene. If you thought a few seconds to render an edit transition was painful, wait until you experience a few minutes per frame for a high quality, moderately complex 3D render. This means you will probably need at least one more computer, so it can render while you get work done on your main workstation. In the meantime, plan your renders for overnight.

A related gotcha is the plethora of render settings you have to understand. Virtually every 3D company claims they have the fastest renderer, but most of their comparisons are at their default lowest quality settings - which are often unacceptable for broadcast work. If you see moiré patterns in the textures and crawling dots along the edges of your objects, you’ll need to increase your oversampling and/or anti-aliasing settings to smooth them, with a corresponding hit in render times - indeed, the idea behind oversampling is to create an image two to 32 times larger than needed, and then scale it down to the requested size in an effort to average out these artifacts. These setting usually have much finer increments than the typical “draft” and “best” in a 2D program; run test renders to see the best balance between quality and speed before rendering the entire scene.

Most 3D programs also have a choice between different rendering algorithms. The “Phong” algorithm is a great balance between quality and speed. The downside is that reflections between objects in a scene do not automatically occur with Phong - you will need to step up to “raytracing” for that (again, with a corresponding hit in speed). Different programs also have different subjective rendering qualities, even when using the same settings and algorithms - this is one of the reasons we personally use multiple 3D programs. Use your eyes, and not the manufacturer’s spec sheets, to decide what works for you on a particular job.

Parts of a Whole

The last area of initial confusion is that the separate tasks involved in completing a 3D scene - modeling, animation, and rendering - are often separate programs that are part of a suite. This is initially even more frustrating that having the CG program separate from your editor; there certainly are advantages to integration. However, this can be a strength down the road, because you can use different modeling or even rendering packages if you are uncomfortable with the tools provided by the main program you bought.