Activity 3: Walk the Plank

Objectives:

Identify elements contributing to immersion
Explain how stereoscopy works to create a 3D image
Describe how tracking and stereoscopy can lead to a sense of presence

This activity will have you take turns putting on the VR headset and reporting your findings to the rest of your team. The rest of the team will ask questions and guide you through the activity. Ideally, you should have two laptops ready, one with this activity, and another for viewing the headset’s screen.

Team Members:

WARNING: Part 2 may induce discomfort such as mild vertigo or nausea. Please use caution and work as a team to avoid falling or bumping into things. If you have acrophobia (a fear of heights), it may be triggering. You may elect to have a different team member wear the headset during this part. Please let the instructor know if you have any questions.

Part 1: Depth Perception

Have one person stand on the arrow and wear the headset.

On a second laptop, make sure you are connected to the JMU-Official-Wireless Wi-Fi network. To view the cast, go to https://www.oculus.com/casting. Log in with the username and password given to you with the headset. Now, follow the instructions to cast the headset's screen to the laptop.

In the app menu, click on the search bar at the top. There should be a little dropdown menu that shows up to the right of the search bar that says "All". Click on it and then scroll down to choose "Unknown Sources". Find the "Act02 – Walk the Plank" app and launch it.

As a team, discuss and answer the following questions:

You should see a tree, a sign, and a mountain. Look straight ahead. Close your left eye and then switch eyes by closing your left eye and opening your right eye at the same time.

Do you see the same exact image for each eye?

You may notice that, although each eye sees the same objects, they are in slightly different relative locations. This is called binocular disparity.

Focus on the sign. Close one eye, then alternate back and forth by closing one eye and opening the other.

Did the sign "move" or change places in your vision?
How did it "move" based on which eye was open?

If this is difficult to see, you may also close one eye and move your head left and right to see the same effect.

Now close your left eye and look at the mountain. Alternate between both eyes again.

Did the mountain "move" in your vision?
Did it move as much as the sign?

Now close your left eye again and look at the tree. Alternate eyes again.

Did the tree move?
Did it move as much as the sign?
Which object "moved" the most when you alternated eyes?
Which "moved" the least?

Consider all three objects.

Which object is closest to you? Which is furthest?
What determines how much something "moves" in your vision?

This displacement of objects based on the object’s distance and your viewpoint is called parallax. The closer something is, the bigger the difference in its perceived position between your left and your right eye.

Your ability to perceive depth this way is called stereopsis. This is because you have a binocular vision system, with two eyes spaced apart horizontally to perceive that parallax effect.

But guess what? The headset is still just a flat screen. You've been tricked by an illusion! Displaying two images to trick your eyes into perceiving depth is called stereoscopy.

→ Click on the "next" arrow at the bottom of the app and pass the headset to a teammate. Please wipe down the face padding and controllers.

Part 2: Walk the Plank

Time for some fun!

Point to the elevator buttons with the controller and pull the trigger. When the doors open, you will see a plank. Don't move yet. Look around the scene.

What do you see and hear?

Have a teammate stay close for safety. When you are comfortable, walk to the end of the plank.

Teammates, observe how your partner walks to the end of the plank.

Do their arms stick out for balance? How do their legs move? What is their reaction like?

At the end of the plank, look around. Talk aloud about how you feel.

Write these feelings down:

You may walk off the plank or turn back to the elevator.

What did you choose to do? Why did you pick that option?
How do you feel?

If it was a little scary, don't worry! You never left the ground and are perfectly safe. Good job!

Did you feel like you were actually there? Why or why not?

You may take off the headset and have your teammates take turns to try walking to the end of the plank and back.

Did anyone feel like they were actually there? Describe your feelings.

Once you are all done, click continue below.

This sense of actually "being there" is called presence.

Which led to a higher sense of presence, viewing on the headset or on the computer screen?
Why do you think that is? What is different between the two?

Submission

Click the Export as PDF button to create a PDF of your answers. Upload it to Gradescope and make sure you select "Group Submission" and include your teammates in the Gradescope assignment!