A computer-generated image is an image taken from one format and is put through different software to create a realistic image. You can also combine CGI images with other images to make them look even more like a real photograph. Say you were making an image to display your product, by making it a CGI, you can see how it would look when the product is actually made. There may be a lot of possibilities when you want to create a CGI image, but finding someone who can actually do it is a lot harder than it looks. The program used to normally create CGI is extremely expensive and complicated. It may be complicated but, CGI images are used in almost every movie, video game, television show, commercial, and media. Whether it's used throughout the whole movie or television show or just used with little figures here and there, it's always used.
It all starts with a drawing. Before it becomes a realistic image, it is drawn out scene by scene, almost like a flip book. If the CGI image the movie or video game is creating is human life, they will take a video of a human speaking and making the gestures that they want the character to make and put it through a lot of software adding more and more detail before it's exactly how they want it. In the movie Ted, Seth McFarland wore a suit that when generated back to the computer simulated that he was an actual teddy bear. The same sensors that were used in Ted are very similar to the ones the actors wore when making Avatar.
Avatar is one movie where CGI and other software are used mainly throughout the whole film. James Cameron, however, used a new software called “image-based facial performance capture.” How he did this was, similar to Ted, he had the actor playing Na’vi were a lot of tiny sensors that tracked her every movement. Each movement was then created into the blue avatar that we see on screen. This software is so exact that Dr. Grace seems younger when she's put into her avatar body but you can still tell that it's her. By the making of Avatar, James Cameron has “forever changed the face of film and theater entertainment.”
Avatar was 60 percent CGI, with other software used, and about 40 percent real action. In this movie, Cameron used a lot of techniques that not many people have tried or used such as “facial performance replacement” and “simul-cam.” FPR, allows him to change the actor's facial expressions. Simul-cam is a camera that allows him to take a CGI image and place it over a real-life character and this allows the CGI image to follow the exact movements of the real-life character. To make sure that his characters are as realistic as possible, he puts a special camera on his actors, that allows him to capture constant images of the actor's faces and then it puts those images into a computer where the avatar is made.
Mountain landscapes, a farmhouse, x-rays, and wet fur, all become computer generated images with just one software system. Just like a flip book, a CGI is made drawing by drawing, until each drawing input together in a matter of minutes to create one scene. CGI is a very expensive and complicated software to use and understand. But in movies like Star Wars and Avatar, it all becomes worth it when you see your work up on the big screen.