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QUIZ 6: Tracking Systems¶

Due date: 2024-10-06 23:59.

Topics:

Vestibular System
Optic Flow
Vection
Orientation tracking
Tilt drift correction
Yaw drift correction
Tracking with a camera
Perspective n-point problem
Filtering
Lighthouse approach

Assumptions:

When the term "vection" is used in the questions below, it specifically refers to visually induced vection. For optic flows, use the following coordinate system:

Question 1¶

Which system in the human body is most involved in detecting balance and motion?

Question 1¶

Which part of the vestibular system measures linear accelerations?

Question 2¶

Which of the following statements is known to be true?

Vergence-accommodation mismatch is the primary cause of VR sickness.

Vection is the primary cause of VR sickness.

Diplopia is the primary cause of VR sickness.

Slow pixel switching speed is the primary cause of VR sickness.

The primary cause of VR sickness is not well understood yet.

None of the above.

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Question 3¶

Which one of the following statements is FALSE about VR screens?

A slow-switching LCD display causes blurring (judder) of the stationary objects to be perceived as the user turns their head.

Increasing frame rate, spatial resolution, tracking accuracy, and FOV will increase realism, and therefore, decrease the amount of VR sickness.

Aliasing problems are worse for VR than for ordinary graphics on a computer monitor.

Even for a 180 Hz refresh rate VR display it is possible to perceive the frame rate if objects in the virtual scene move fast enough.

Lower persistence displays reduce judder (motion blur) in VR, as they decrease the amount of time during which retinal slip occurs.

None of the above.

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Question 4¶

Which of the following statements about vection is FALSE?

Vection is often associated with VR sickness.

Vection is the illusion of self-motion.

Vection is a result of sensory mismatch between human vestibular and visual senses.

Illusory perception of stationarity is what is commonly referred to as vection.

Using a controller to rotate an avatar in place at constant angular velocity often leads to vection.

None of the above.

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Question 5¶

Which of the following statements is TRUE about vection in VR HMDs?

Vection is the conflict between human vision and hearing systems.

Self-rotations of an avatar using a controller in Virtual Reality is considered comfortable, as long as the angular velocity is constant.

Vection is the perception of stationarity in VR, produced by accurate tracking of the user’s head and body.

Discomfort brought in by vection does not improve, even after repeated exposure to VR.

None of the above.

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Question 6¶

Which one of the following optic flows is always guaranteed to lead to vection?

Translation along the x-axis with constant velocity.

Translation along the y-axis with constant velocity.

Translation along the z-axis with constant velocity.

Rotation around the x-axis with constant angular velocity.

Rotation around the y-axis with constant angular velocity.

Rotation around the z-axis with constant angular velocity.

None of the above.

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Question 7¶

Which of the following statements is FALSE about optic flows in VR HMDs?

Optic flow is the pattern that visual features of an environment create on the retina of an observer.

The patterns of optic flow differ depending on the speed and direction of an observer's movement and the layout of the environment.

Optic flows generated in VR HMDs always lead to vection.

Optic flow can be generated by a VR experience, even if the user is physically motionless.

None of the above.

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Question 8¶

Which motion should NOT cause vision-vestibular mismatch when moving an avatar using a controller?

Question 9¶

When moving an avatar using a controller it is considered to be most comfortable to _______.

Question 10¶

For large menus in VR, it is considered to be most comfortable to present ____________.

a floating menu by turning the head tracking off so that the menu follows the user’s head.

a floating menu that is located close to the user's eyes (less than 10 cm), so that it is clearly visible.

a stationary menu that is locked to the environment.

a floating menu that occupies most of the user's field of view.

None of the above.

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Question 12¶

Which of the following statements is FALSE about latency in VR HMDs?

Motion-to-photon latency is affected by several factors, including the quality of the tracking system, the processing power of the VR software and graphics card, and the hardware technology of the VR headset.

Motion-to-photon latency is defined as the amount of time it takes for the graphics card to perform the rendering pipeline computations.

Many modern VR devices have 0ms ''perceived'' latency.

Before Oculus, VR devices had 60ms latency and higher.

None of the above.

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Question 13¶

Question 14¶

Question 15¶

Question 16¶

Question 17¶

Question 18¶

What is the primary function of VR tracking hardware?

Question 19¶

Which of the following statements is FALSE about VR tracking hardware?

Cameras are essential for high quality tracking in 3DOF VR HMDs, such as VR Cardboards

An accelerometer measures linear accelerations, including due to Earth gravity.

Many of the modern VR headsets contain the following tracking hardware: a camera, an accelerometer, a gyroscope and a magnetometer.

Cameras are used for drift correction in modern VR tracking systems.

None of the above.

Varoitus: Et ole kirjautunut sisään. Et voi vastata.

Question 20¶

What should you do if a user feels dizzy or nauseous while using VR to maximize the user's comfort?

Authors¶

Anna LaValle.

Anna palautetta

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