UNIT-4 3D INTERACTION TECHNIQUES IN AUGMENTED AND VIRTUAL REALITY || SHORT QUESTION ANSWER || AKTU NOTES

 SHORT QUESTION ANSWER

Q 1. What is GO-GO Technique?

Ans.The “Go-Go” technique attempts to improve on the simple virtual hand by providing an unassuming technique that allows the user to interactively change the length of the virtual arm. When the user’s real hand is close to the user, Go-Go uses a one-to-one mapping like simple virtual hand, and the movements of the virtual hand correspond to the real hand movements.
However, when the user extends her hand beyond a predefined distance threshold, the mapping becomes nonlinear and the virtual arm “grows,” thus permitting the user to access and manipulate remote objects.

Q 2. How many techniques are used for selection and manipulation?

Ans.There are six techniques which are used for selection and manipulation:

• Grasping
• Pointing
• Surface
• Indirect
• Bimanual
• Hybrid

Q 3. What is 3D Interaction technique?

Ans. 3D Interaction Techniques are the different ways that the user can interact with the 3D virtual environment to execute different kind of tasks. The quality of these techniques has a profound effect on the quality of the entire 3D User Interfaces.

Q 4. What is Canonical Manipulation task?

Ans: Canonical Manipulation Task- The fundamental assumption of any task analysis is that all human interactions of a particular type are composed of the same basic tasks, which are building blocks for more complex interaction Consequently, if we can distill 3D manipulation into a number of such basic tasks, then instead of investigating the entire task space of 3D manipulation, we can design and evaluate interaction techniques only for this small subset. The results can be then extrapolated to the entire space of 3D manipulation activities.

Q 5. What is Control-display mappings?

Ans: The software components of interaction techniques are also known as control-display mappings or transfer functions, and they are responsible for translating information from the input devices into associated system actions that are then displayed to the user.

Q 6. What is task in 3D?

Ans: Virtual 3D manipulation imitates, to some extent, general target acquisition and positioning movements that we perform in the real world—a combination of reaching/grabbing, moving, and orienting objects. Virtual 3D manipulation also allows users to do that which is not possible in the real world, such as making an object bigger or smaller.

Q 7. Define isomorphic in 3D manipulation?

Ans: Isomorphic- The isomorphic view suggests a strict, geometrical, one-to-one correspondence between hand motions in the physical and virtual worlds on the grounds that it is the most natural and therefore is better for users.

Q 8. Define non-isomorphic in 3D manipulation?

Ans. The non-isomorphic approach deviates significantly from strict realism, providing users with “magic” virtual tools such as laser beams, rubber arms, voodoo dolls. These non-isomorphic mappings and techniques can allow users to manipulate objects quite differently than in the physical world.

Q 9. What is Intent Driven Selection?

Ans.In this intent-driven selection as an enhancement for finger-based grasping techniques.
The concept of intent-driven selection is to use the posture of the virtual fingers as an indication of the user’s level of confidence in selecting an object.
The intent-driven selection enhancement enabled users to select objects faster and more efficiently than a conventional finger-based grasping technique, especially for challenging selection tasks.

Intent-driven selection employs proximity spheres to progressively refine the selection of objects.

Q 10. Write down the three approaches of indirect techniques?

Ans: We have categorized indirect metaphors into three distinct approaches—control spaces, proxies, and widgets. Control-space techniques separate control from the display by allowing the user to interact in a physical space distinct from the apparent location of the virtual environment and mapping those interactions to the environment. Proxy techniques have the user directly interact with proxies (i.e., representative copies of objects within the virtual environment) and then map those manipulations onto the original objects. Widget techniques place within the virtual environment widgets that the user can directly manipulate.