3D modeling and rendering is one of the most processor intensive tasks a computer can perform. A few years ago the 3D effects and animation you saw on TV or in the movies were generally created on expensive workstations manufactured by Silicon Graphics. These computers cost tens of thousands of dollars each and Hollywood special effects companies like Industrial Light and Magic would employ huge fleets of them to render the individual frames of movies like Jurassic Park.
Due to the exponential increase in speed and power of personal computers, these days more and more of this work is done on PCs and Macintosh computers. This means for an investment of less than $10,000 anyone can buy a high-end Mac or PC and a good 3D software package along with a video editing application and produce broadcast quality 3D film or video animations.