3D SPACE: Using Depth and Movement for Selection Tasks

This paper is the result of a research made by Dr. Dale Patterson on how users utilize and interact with content in a 3D space. More specifically he presents two new three dimensional interface components (The Flow and Circulatory system) that use the depth provided by 3D computer graphics to present complex information in a natural three dimensional form for user interaction. Last but not least, Dr. Dale Patterson introduces the concept of “active 3D interfaces”, a new style of interface that presents its data to the user rather than statically waiting for the user to interact with it. The paper can be obtained through the ACM website.

Active Components
The concept behind the Active Components is to use the natural human understanding of 3D space and the motion of objects in that space. The key principles used in the conception of the components are the use of depth and of motion through depth. The use of depth is to facilitate the presentation of large sets of complex information in an easier to understand and more natural form. While the use of motion through depth is due to the fact that the world is alive with motion and activity, so makes it a key aspect in the presentation of data in a 3D space. In essence, active interfaces are not simply statically waiting for the user to interact but are actively presenting their information through the motion and animation of items in the 3D space.

Flow Component
The Flow Component represents a new interface (or interaction technique) designed for presenting large sets of unstructured data. An example of this kind of data would be the results obtained from a web search for a particular topic. The common approach used in modern GUI interfaces is to provide the user with a large two dimensional list of results, which then he has to manually scroll through to locate the desired item. The flow component looks at this data in a different way.  Rather than treating the result set as a static two dimensional item (in the form of a large textual page) that the user needs to  move through, the flow component looks at the result data as a  flow of three dimensional items. That is, have the results flow out at the user from the depths of the screen. The use of depth to display the set of items allows a larger set of items to be displayed at any one time than would be possible in any 2D arrangement. At the same time, the use of movement through 3D space over time is used to enable the set of items to flow past the user, allowing him to see all the items in detail as they pass by without having to make any interaction.

Circulatory System
The circulatory system interface/component represents an extension of the principles established by the Flow component. Unlike the Flow (which presents unstructured data sets) it presents a new method for the presentation of large structured sets of data (e.g. selecting or locating a movie from within a large collection or library of movies). Extending from the basic flow concept, the Circulatory System takes the idea of a flow and creates a flowing loop (much like the human circulatory system). The items would loop past the user showing all options over time, without the user needing to navigate through the structure. Of course that more complexity can be introduced by creating more complex forms of loops and sub loops, allowing the user to have some control in their ability to choose which branches to take.

Experimental Results
To establish the effectiveness of the new 3D components, Dr. Dale Patterson made a series of test to a group of 14 trial users. All the experiments consisted in the user completing a task with the relevant 3D component and also completing that same task with a number of other interface versions (i.e. some 2D systems, others simply variants of the primary 3D component). After the trials it was possible to conclude that 3D computer graphics demonstrate potential in a range of common interaction tasks, being in many cases more effective than current systems. The active interfaces proved particularly effective in tasks such as browsing large structured and unstructured sets. In simple terms the addition of motion (active interfaces) and depth (3D space) has demonstrated potential to be an effective method for improving the human computer interface in these common real world tasks.


Principles of traditional animation applied to 3D computer animation

As the title of this post reveals, I’m going to present a paper about principles of animation that should be applied to 3D computer animation and that are useful in the design of 3D interfaces. The paper was written by John Lasseter, the Chief Creative Officer at Pixar and Walt Disney Animation Studios, and can be downloaded through the ACM website.

John Lasseter gives an historic overview over the the 11 principles of traditional animation defined by the Walt Dísney Studio and then gives an explanation of each one of the principles, relating them to the field of 3D computer animation. Next is a summary on some of the principles presented in the paper:

Squash and StretchDefining the rigidity and mass of an object by distorting its shape during an action
This is the most important principle and says that when an object is moved the movement emphasizes any rigidity in the object. The squash position represents when an object is flattened by an external force or when the object is constricted by its own power. The stretched position will show the same form in a much extended condition.  One important rule about squash and stretch is that the volume of the object has to remain constant during the movement or else the object would look as it had shrink or grown during the process. This principle defines the rigidity of the material that compose the object, i.e. depending on the level of stretch and squash the object would look as is made of different materials.

TimingSpacing actions to define the weight and size of objects and the personality of characters
It represents the speed of an action, giving meaning to the movement and defining how well the idea behind the action will read to an audience. It also reflects the weight and size of the object, as well emotional meaning. It’s important when defining the timing of a scene, to make sure that the audience is capable of reading and understanding the meaning of it as fast as is being shown. Another aspect related to timing is the weight of the objects. A heavy object will have a slower acceleration and deceleration than a light object, and will take a bigger force to change is motion. Timing can also give a feeling of size and scale to an object, by making a huge object with enormous mass to move slowly and a   small object with a small mass to move quickly. Last but not least, timing can show the emotional state of the object by varying the speed of his movements, indicating whether the character is lethargic, excited, nervous or relaxed.

AnticipationThe preparation for an action
Anticipation is used to catch the audience’s eye and to prepare them for what the next movement will be before it happens. The amount of anticipation used considerably affects the speed of the action which follows it. If the audience expects something to happen, then it can be much faster without losing them. This principle is also used to direct the attention of the audience to the right part of the screen and at the right moment, preventing the audience from missing some vital action. Anticipation can also emphasize heavy weight, as for a character picking up an object that is very heavy. An exaggerated anticipation, like bending way down before picking up the object, helps the momentum of the character to lift the heavy weight.

StagingPresenting an idea so that it is unmistakably clear
Staging is the presentation of an idea so it is completely and unmistakably clear, whether it’s an action, a personality, an expression or a mood. To stage an idea clearly, the audience’s eye must be led to exactly where it needs to be at the right moment, so that they will not miss the idea. That is accomplished trough staging, anticipation and timing. One important aspect, when staging an action, is that only one idea should be seen by the audience at a time. Due to that the object of interest should contrast from the rest of the scene, preventing the user of overlooking the idea being transmitted when there is a lot of action happening at once.