Introduction to 3D Technology

Introduction

Also, in the Star Wars movie there were scenes where 3D holographic images were projected, allowing the person doing the viewing to walk around and view the image from a different perspective.

While there are technologies in work to create true 3D scenes, these are not the technology that most folks think of when the term 3D is used. In photographs and on computer screens, the term 3D graphics is used to describe the generation of images which give the illusion of depth. The image 'moves' on the screen, rather than requiring/allowing the viewer to move.

The term "scene" is universally used to describe the image and all the objects contained in it.

Just like in traditional movies, multiple 3D images are displayed sequentially (~20 images per second) to give the illusion of motion, but with 3D images the illusion is often one of moving "around" in the scene - of moving between objects and of seeing the objects from different perspectives, including perspectives within the scene itself.

The same effect can be accomplished by using a series of photographs taken as a camera is moved through a scene, but the point of 3D graphics is to create those images using computer and software technologies in order to give greater control on individual objects with the scene, as well as to provide greater creative control of how objects appear (or move) within the scene. The ultimate goal of 3D graphics technology is to provide photo-realistic images with the added ability to manipulate every aspect of the image - colors, lighting, textures, position, and more.

While 3D animation may get the lion's share of the press, mostly because of it's use in movies, the far greater number of 3D artists and graphics designers are involved in making individual 3D images - photo-realistic images which give the illusion of depth.

Creating a photo-realistic image often takes an enormous amount of effort on the part of the 3D graphics designer (note: I will use the term 3D graphics designer frequently, so if you consider yourself a 3D artist, please do not take offense). Designing the objects within the scene, determining colors and textures, and getting the lighting just right are just some of the details that must be worked out. Other details in an image, such as shadows and reflections, are usually generated by a computer and can require several seconds (if not hours) to generate.

The result is that a high quality, photo-realistic image image can take hours to create.

Elsewhere in this site I will cover a variety of technologies (mathematics and software) used by 3D graphics designers. While it is fair to say that 3D images are getting more and more photo-realistic every day, no one can say that the 3D images have reached the goal of true photo-realism today. The tools for such image quality are improving every day, but still have a ways to go to reach the point of being indistinguishable from photographic images. And despite the enormous power of today's computers, the hardware computational requirements of true photo-realism (especially real-time generation of images) is still of out reach.

Even so, as any movie goer can tell you, there are some exceptional 3D images being generated by today's graphic designers and artists. Particularly for the case where a single image is needed, today's computing power and mathematic/software techniques can be very effective.

On the one hand, there are excellent mathematic and software techniques for approaching photo-realism in a single image - but most of these require the simple use of massive, raw computing power. When PCs have advanced to the point where we all have the equivalent of a Cray Supercomputer on our desktop, then real-time photo-realistic 3D images will be available.

Despite my claim that single image generation is where the bulk of 3D graphics artists spend their time, it is animation that gets the most press time. Whereas single 3D image quality can be excellent, the time and effort required to generate a complete animation (~20 images per second) can be enormous - well beyond the resources of most would-be 3D animation artists.

For sure, use of a computer to generate images is part of the solution. The days of Walt Disney, where invidual images were draws one at a time by artists, are fading. While full length motion pictures and commercial advertisements, with their larger budgets still use this technique extensively, other areas of 3D animation have to look to other solutions.

Movies and advertisements have something in common - their high-quality, photo-realistic images are created in advance, stored, and then displayed to the consumer on demand.

The two other major drivers of 3D technology - video games and web site animations - cannot use that approach. It's simply not feasible for most game/web masters to spend the time and money that it takes to create thousands of photo-realistic images. Nor is it feasible to expect users of game or visitors to web sites to store/download the enormous files that photo-realistic images require.

Because of these very basic limitations, virtually all 3D work in games and at web sites are focussed on working the tradeoff between photo-realism and real-time, affordable animations.

With games, the real-time aspect is most crucial. Today's games are very fast-paced and users are not willing to sit patiently while the computer draws a great image. Game players are willing to settle for reduced quality images in order to maintain the pace of the game. Game artists often settle for images that are "good enough" - and continue to look for ways to improving the images.

Likewise, web site visitors are only willing to wait seconds - not minutes - for an animation to download for viewing. If animations are to be an integral part of web sites, web masters have to find ways to provide them with as little detectable delay as possible.

While the eventual goal of 3D graphics artists is provide real-time generation of photo-realistic images, today's technologies as discussed throughout this site have begun to approximate that goal.