Digital presentation techniques exist in a few categories. There are 3-dimensional renderings of potential built environments (see below), digital drawing styles, and digital animations (video). There are clear pros and cons to each of the categories. Digital drawing styles such as CAD have been very influential in the development of efficient drafting. Other styles of digital drawing produce results that can be as stimulating as any hand-drawing style. Often, a combination of both medias provides a good solution. 3-Dimensional renderings (images) can also be very helpful in depicting possible material choices and site placement. The problem with these renderings is the fantasy-like quality that they often carry. Projects that utilize 3d renderings often appear more exciting than any real building could ever be. There is no need to conform to rules such as structure and cost, so often the buildings appear idealized and supernatural in some ways. This is not necessarily a problem for student projects that will never be built, but for projects that are pitched to clients. If a client sees a building that glistens, reflects and maintains pristine characteristics in a rendering, he or she will be disappointed when the building is actually erected. Animations are perhaps ideal in providing viewers with accurate interpretations of the space. They can be as visually stimulating and as accurate as the renderings can be. The cons of producing an architectural video lie in its accessibility. In order to show a video, one needs access to a computer. Images can be printed out, but that technology has not yet been invented for video. Hopefully, the accessibility of videos will rise in the future in conjunction with the development of personal media devices.