We make images to communicate. The ultimate measure of the quality of our images is how well they communicate information and ideas from the creator’s mind to the perceiver’s mind. The efficiency of this communication, and the quality of our image, depends on both what we want to say and to whom we intend to say it. I believe that computer-generated images are used today in two distinct ways, characterized by whether the intended receiver of the work is a person or machine. Images in these two categories have quite different reasons for creation, and need to satisfy different criteria in order to be successful.
Consider first an image made for a machine. For example, an architect planning a garden next to a house may wish to know how much light the garden will typically receive per day during the summer months. To determine this illumination, the architect might build a 3D model of the house and garden, and then use computer graphics to simulate the illumination on the ground at different times of day in a variety of seasons. The images generated by the rendering program would be a by-product, and perhaps never even looked at; they were only generated in order to compute illumination. The only criterion for judgment for such images is an appropriate measure of accuracy. Nobody will pass judgment on the aesthetics of these pictures, since no person with an aesthetic sense will ever see them. Accuracy does not require beauty. For example, a simulation may not produce images that are individually correct, but instead average to the correct answer. The light emitted by the sun may be modeled as small, discrete chunks, causing irregular blobs of illumination on the garden. When these blobs are averaged together over many hours and days, the estimates approach the correct value for the received sunlight. No one of these pictures is accurate individually, and probably none of them would be very attractive.
When we make images for people, we have a different set of demands. We almost always require that our images be attractive in some way. In this context, attractive does not necessarily mean beautiful, but it means that there must be an aesthetic component in?uenced by composition, color, weight, and so on. Even when we intend to act as analytic and dispassionate observers, humans have an innate sense of beauty that cannot be denied. This is the source of all ornament in art, music, and literature: we always desire something beyond the purely functional. Even the most utilitarian objects, such as hammers and pencils, are designed to provide grace and beauty to our eyes and offer comfort to our hands. When we weave together beauty and utility, we create elegance. People are more interested in beautiful things than neutral things, because they stimulate our senses and our feelings.