Shane’s Summaries Week 2.


Virtual Environments for treating fear of heights:

Basically they tried to treat acrophobia by placing subjects in Virtual Environments where their fear would be stimulated by the environment.  They used a cluster to draw and render their scenes on a head mounted  display and on external monitor  so that a psychology student could observe what patients were seeing.  There were 20 patients in the study with 17 completing it.  They had 3 types of environments:  an external elevator with a railing, balconies, and a bridges that spanned a canyon.  They also constructed models of the balcony and elevator which matched their virtual kind perfectly.  They would then place the subjects in the environments at varying heights in the case of the balconies and elevator.  For the bridges they have several bridges with the stability of the bridge decreasing as the height increased.   The canyon level also has a birds eye view mode in which the subject looks down upon all of the bridges from a point in the sky. Interestingly they were able to trigger physical responses in the patients ranging from nausea to weakened knees.  Weekly exposure was able to reduce the fears of the patients.  They measured the affect of the system by using surveying the patients anxiety level several times throughout the testing period.

Theme Park VR:

This short paper describes the construction and testing of a theme park virtual reality game.  The game is played in a simulator of sorts where the players stand on a small ship with cannons and a steering wheel.  A screen surrounds  the outside of the ship and it has surround sounds as well as lights and motion.  In addition the players can also wear 3D glasses.  A special emphasis is placed on making the game easy to learn, making it exciting, and visceral.  They used different tricks to lead the players into the exciting parts of the game like guide ships and visual attractions.  The game also “punishes” the player when they do not go to the exciting parts of the level.  It does this by only allowing to travel so far from the islands in the game before being bounced back by a force field.  And ships will attack them from behind during quiet periods. Also forcing the players to run around on the small helps make the illusion real.  The system was iteratively developed with most of the time being spent on balancing the game and polishing it.  Like most games it was played tested several time during the development process.


They attempted to build  an augmented reality in which they use ultrasound imaging to display three model.  The system uses ultrasound 2D slices to build a 3D model.  They reduce the noise by using some statical operation and filters and then using ray casting to actually render the model over the real world object.  This idea has some problems.  Ultrasound returns are very noisy and contain lots of information that may or not be useful such as blood vessel locations.  They use a Head mounted display that doesn’t block the users vision.  The information is draw on top things that exist in the physical world.  Being able to see the real world through the display is an obvious requirement but causes some major issues.  The system is slow compared to the ability of the user to move around which creates a noticeable lag between the time the user turns there head and when the AR images correct themselves.  Tracking was also an issue in the system because of the quality of the sensors contained within the head mounted display.  Interestingly the users felt that he 2D ultrasound slices were painted on the surface of the patient rather than being shown inside of them.  To solve that particular issue they tried using 3D pits that would cover the patient and better create the illusion of depth.  Obviously though the pit then covers up and prevents the user form seeing what’s under neath.

4 Responses to “Shane’s Summaries Week 2.”

  1. Shane says:

    Okay… SO:

    1. Is everyone supposed to write a summary of every paper every week? If so why isn’t there more posts?

    2. More details or is this level of detail enough?

    • Mukul Sati says:

      1. We are. I guess we’ll see more incoming! Can’t help you on the two – myself have not a clue :(.

  2. I suspect most folks won’t submit them till closer to class time (ah, the joys of procrastination … er, time management!).

    That said, they are a bit on the short side, but ok. The first is 146 words, which is a little below 200-300, but acceptable. 2nd is a bit short. 3rd … well. 0 words?

  3. Shane says:

    I can beef them up some. I was writing the summaries after I read the papers lol. I’ll add the third now.