Class Notes #10 & 11
The User Interface - Defining visual space in information systems
Reading: Manovich - Chapter 2 "The Interface" (pp 62-115)
Class discussion on this chapter.Class Discussion Questions:
- why is the "interface" such an important aspect of new media?
- what impact has "interface" on our method of work? play?
- how does "interface" work in the manipulation of 2d, 3d data?
- others....
2D Images
Scanners - digitizing the 2d page. We will work through this introduction to scanning and digitizing of images (from "howstuffworks.com").
Film Scanners - very high resolution scanners exist to digitize film. The norm today (though it won't last) is called "2k". That means that for every scan line there are 2048 samples at (usually) 24 bits per sample. So for a single line of scanned information we would acquire 2048X24 bits = 49152 bits/line OR 6144 bytes/line (8 bits = 1 byte). Depending on the format, there are up to 1080 vertical lines. Hence the total byte count for a SINGLE FRAME is: 6144X1080 = 6.7 megabytes. But a frame is 1/24th of a second, so for each second we would accumulate 24X6.7megabytes = 160 megabytes. For each minute then we would have 9648 megabytes or roughly 10 gigabytes per minute. A 90 minutes feature film would generate 900 gigabytes of image data. That's a lot. Moreover, when a film is being made, the production may acquire up to ten times the footage that ends up being used. So that would be 9000 megabytes or 9 terabytes! To make matters worse, it is expected that the 2k/line resolution will not prove to be sufficient - we are already seeing 4k and 6k systems and these scan resolutions could go even higher.
Graphics, bitmap, objects...
Scanned 2D images, like sampled music, consist of a set of numerical (digital) values that represent the original image. These are essentially "bit-maps" in that they contain only the data that describes each pixel. For example, when you scan an image and open that image in Photoshop, you can alter every single pixel using a variety of commands.
However, this not how images are normally created in a computer (with the exception of "paint" programs). Graphic images are computed from algorithms that describe shapes. For example, a straight line can be described by a simple equation such as y=mx+b. Other geometries produce other computable shapes.
For an in-depth tutorial on graphics programming see: lode
Image Techniques:
Paint Programs
These have been around a long time. There are many excellent painting and drawing software systems ranging from very simple ones like "Mac Paint" to very elaborate such asTwisted Brush (winxp). In "paint" programs, individual pixels are directly manipulated. These are also called "raster" drawing. (see next entry). One of the most widely used is PaintShopPro (win) - note use of "picture tubes" - analgous to "samples or loops" in our last project.
Vector Graphics
This class of software uses line drawing, shading and filling to make images. These can be 2d or perspective 2d which appears to be 3d. The advantage of this type of drawing program is that the "objects" can be manipulated by various processes and algorithms. The most famous of these is Adobe Illustrator. The difference between vector programs and paint (raster) programs is described here.
Photoprocessing
This class of software has exploded in usage due to the ubiquity of cheap digital cameras and scanners. Of course the most famous of these is Adobe Photoshop which provides a "paint" and "text" subset of operations along with a vast collection of photo retouching and processing. Here are some Photoshop examples.
Grade 9 Students - Japan ; Fantasy/Special Effects ; Photoshop Bootcamp
Computatational Images
Fractals
"Basically, a fractal is any pattern that reveals greater complexity as it is enlarged. Thus, fractals graphically portray the notion of 'worlds within worlds' which has obsessed Western culture from its tenth-century beginnings." Alan Beck
We will work through this site: Cynthia Lanius Fractal Tutorial
Fractals: Gallery 1; gallery 2; gallery 3
Plasma synthesis
Using sinusoidal functions and other repetitive operations, one of the most familiar computer generated image is the "plasma" effect. Here are the details and examples from lode, "plasma". Examples of this early technique abound. Here is a page of examples that can be used as "textures" overlayed on vector or other modeling systems.
Raytracing
This technique uses precise descriptions of the paths of one or more light sources to "compute" the actual results of the light rays. Some of the most impressive graphics advances of the 1980's were based on raytracing over 3d models. Examples are easy to find - here are some good ones. Here are some examples from a UT course! Note the strong emphasis on 3d shading and photorealism in these. Unfortunately - this technique become a cliché and these very obvious techniques are now used in less obvious ways. But raytracing is a key method in all 3d computer generated imaging.
3d modeling (wireframe)
The basis of most 3d animation is the formation of a model of the object(s) constructed from a set of polygons. This often referred to as a wireframe of the object that will then be "tiled" or painted in some fashion. A quick tutorial appears here. The wireframes are formed using software that can generate the 3d frames directly from code or by extruding 2d drawings of the object. One of the best known programs is "Softimage". It was used to make many extraordinary effects for movies such as Terminator 2. These 3d modeling systems can produce stunningly realistic results. Another major vendor is Alias-Wavefront and they pose a "test" of realism. Alias produced "Maya" which is now used throughout the 3d imaging community.
Virtual Reality
Using the most advanced computational techniques, it is possible to generate "virtual worlds". Some of these are presented on screens, others are viewed using special headsets or even full-body suits that permit the participant to "see, hear, feel" the entire artificial world. Probably you have all seen "The Matrix" and have some sense of the idea of alternate cyber-worlds. Here is an example of VR being incorporated into traditional theater and opera at the University of Kansas where artifical scenery is projected into the theater space. Magic Flute. The next example shows the "immersive" approach. The following shows some browser viewable "vr" sequences from commercial sources.
Here is the most advanced environment today - called the "Cave" developed in 1991 at the Experimental Visualization Lab, University of Illinois - Champagne-Urbana. It is now sold commercially by Fakespace Systems.
3D Modeling, Computer Animation
Macromedia FlashMX - wireframe animation; showcase ; movie gallery
3D Studio Max gallery (italy); books and training; commercial models
Alias Motion Builder -Maya animations (gallery, gallery2,
Pixar - renderman and proprietary software
Digital video editors
Final Cut Pro - Tutorial (Rice University) ; imovie - tutorial
Digital video effects