The “mission statement” for photorealistic rendered is the most important reason why photorealistic rendering has been so popular. “Create a picture that is not distinguishable from a photographic image.” This mission statement gives photorealistic render a visual “Turing Test” and a clearly defined metric to ensure a successful image. It is difficult to have one mission statement in artistic computer graphics. Instead, researchers are trying to achieve a variety image creation goals. Artistic computer graphs aims at simulating traditional artistic media and understanding the human visual process. They also aim to communicate effectively with low bandwidth, abstract images, improve learning and enhance user interaction.
Artistic computer graphics has become synonymous with the control of image detail for communication. This combination of control over image detail and stylization can be used to create the impression that an image is complex without requiring explicit representations. Artistic images offer a more natural medium for communicating information at different levels. These are seven situations where an artistically created image has an advantage.
1. Image reproducibility: Full-shaded three-dimensional geometry printed in black/white may not print well in a technical magazine. Photographic images cannot be faxed or copied as well as line-art images.
2. Medical Visualization: Researchers have been working on creating artistic algorithms that can interactively be used to display volume data. One good example is the visualization inside the body of electric fields.
3. Communication of Abstract Ideas. Our visual system expects characters realistically rendered to behave as they should. Nonphotorealistic animated animation can be used for ideas that are beyond the physical and logic norm. This is acceptable for a large audience. Force diagrams, which are found in physics textbooks, are an example.
4. The ability to evoke the imagination: A simple line drawing can communicate abstract ideas in a way a photograph can’t. The photorealistic image shows every detail in the scene, so the imagination is left empty. By not displaying every detail, a photorealistic image lets the viewer share in the interpretive process.
5. Animation: The key to creating animation is to direct the viewer’s attention on the appropriate actions and elements within the scene. A viewer can lose the big picture if they focus on the small details of a photorealistic scene. An economy of line is a nonphotorealistic technique that reduces the detail in a scene. It makes animators more effective at directing attention.
6. Compression: By not depicting all the detail required for photorealistic images, nonphotorealistically rendered computer graphics images typically take less time to create, can be rendered to the screen faster, and use less storage space. Half-tone images are, when viewed from far away, the same shape as traditional computer graphics images. Half-tones require approximately one tenth to one one thousandth of the storage area.
7. Communication of design or process completeness: A photorealistic rendering requires an exactness and perfection that can overstate how close the scene is to a photograph. The viewer may be able to see that the image is not a true representation of the scene. Artistic computer graphics can assist them in this understanding. Architectural rendering is an example of this phenomenon. Architects know that the local building codes vary and can result in last-minute changes to plans. Clients may be surprised to see the actual building and feel disappointed. If the clients are shown photographs of the proposed structure, clients will accept the design process as imperfect and the plans as subject to change. Clients usually allow for on-site modifications.