Influence of control/display ratio on the perception of mass of manipulated objects in virtual environments

IEEE Proceedings. VR 2005. Virtual Reality, 2005. (2005), pp. 19-318, doi: 10.1109/VR.2005.1492749
Experiments
Tasks
Findings

We do not know today the effect of modifications of the C/D ratio on the perception that the user has of the virtual environment and more especially of the virtual objects he/she manipulates. For instance: does the use of a C/D ratio different from 1 influences the perception of haptic properties of manipulated objects such as their mass? The present study aims at bringing some answers to these questions.

Variables and Constants

    Haptic Fidelity
  • haptic quality - the control / display ratio was varied. with a c/d ratio of 1, moving the foam ball 1 inch would translate to the rendered ball moving 1 inch on screen. the reference ball was always displayed using at c/d ratio of 1 while it varied for the other weights
Independent Variables
Constants

The size of the ball, the control / display ratio of the reference ball, the amount of time to determine the balls weight (6 seconds), and simulated gravity was on.

System Info

Displays
  • monitor - 21" screen in monoscopic condition, with a frame rate of 85hz
Input Hardware

Participant Info

All right handed. Mean age was 29.7 with sd = 7.1

Total # Age Range Gender Balance
10 23 - 46

The participants were to watch a 3d rendering of the ball floating above a plane on a monitor. In their right hand they held a foam ball that was attached to a haptic device programed to simulate the weight of the ball. View of their arm and of the haptic device was obstructed. After 6 seconds of weighing the ball, they would indicate whether the first or second ball was heavier. Weights of the balls and the control / display ratio was varied between trials.

Interaction and Environment

Interface

Users would key a response of 1 or 2 with their left hand to indicate whether the first or second ball was heavier.

The ball was rendered floating above horizontal plane and had the same radius and color as the ball attached to the haptic device. View of their right arm and haptic device was obstructed. When the experiment started, the device simulated gravity and inertia on the ball.

Dimensionality Scale Density Visual Realism
3D Medium Low Low
Metrics

  1. There was a significant direct effect of haptic quality on accuracy for a interactive experience of the ve task.

    Lower C/D ratio resulted in less correct answers for determining ball weight with gravity simulated


    May be only limited to situations in which the arm and feedback device is not visible.

We do not know today the effect of modifications of the C/D ratio on the perception that the user has of the virtual environment and more especially of the virtual objects he/she manipulates. For instance: does the use of a C/D ratio different from 1 influences the perception of haptic properties of manipulated objects such as their mass? The present study aims at bringing some answers to these questions.

Variables and Constants

    Haptic Fidelity
  • haptic quality - the control / display ratio was varied. with a c/d ratio of 1, moving the foam ball 1 inch would translate to the rendered ball moving 1 inch on screen. the reference ball was always displayed using at c/d ratio of 1 while it varied for the other weights
Independent Variables
  • simulated weights - the simulate weights of balls varied to 170g, 210g, and 310g while the reference ball was kept at 100g.
Constants

The size of the ball, the control / display ratio of the reference ball, the amount of time to determine the balls weight (6 seconds), and no gravity simulated.

System Info

Displays
  • monitor - 21" screen in monoscopic condition with frame rate of 85hz
Input Hardware

Participant Info

8 men, 2 women. mean age 31.7 with sd = 11.3 All right handed with no known perception disorders

Total # Age Range Gender Balance
10 22 - 60

The participants were to watch a 3d rendering of the ball floating above a plane on a monitor. In their right hand they held a foam ball that was attached to a haptic device programmed to simulate the weight of the ball. View of their arm and of the haptic device was obstructed. After 6 seconds of weighing the ball, they would indicate whether the first or second ball was heavier. Weights of the balls and the control / display ratio was varied between trials.

Interaction and Environment

Interface

Users would key a response of 1 or 2 with their left hand to indicate whether the first or second ball was heavier.

The ball was rendered floating above horizontal plane and had the same radius and color as the ball attached to the haptic device. View of their right arm and haptic device was obstructed. When the experiment started, the device simulated gravity and inertia on the ball.

Dimensionality Scale Density Visual Realism
3D Medium Low Low
Metrics

  • accuracy - were the participants right in their comparison
  1. There was a significant direct effect of haptic quality on accuracy for a interactive experience of the ve task.

    Lower C/D ratio resulted in less correct answers for determining ball weight without gravity simulated

    Specificity: Somewhat general
    May be only limited to situations in which the arm and feedback device is not visible.