Lecture 8 - 3D Interaction Challenges

Question 1

What are the 4 areas of interaction challenges for 3D systems?

Answer 1

• ergonomics (how to make use comfortable)
• legibility and readability (being able to see , understand and perceive content)
• awareness of reality (staying safe in the real world)
• physical space (moving both in physical and virtual world)

Question 2

Challenges involved with ergonomics?

Answer 2

• can users comfortably reach content (is it close enough to interact and read)
• if something cannot be reached is there an alternative way to reach it (ray-casting? egocentric content positioning? bring stuff to the foreground?)
• can users comfortably perform movements we ask them to perform (excessive head rotations (neck fatigue) , excessive arm or body movements (gorilla arms) )
• how quickly will users tire from the interaction? (is there excessive physical demands , try keep arms near torso for long interactions , use ray-casting to minimise reaching , minimise dwell times to reduce interaction duration ) => could use the consumed endurance model to check cost

Question 3

Challenges related to Legibility and Readability?

Answer 3

• how easily can users read text and understand information? (should be closed enough and not distorted, occluded,badly angled or unreadable due to lack of contrast with background)
• text should be readable at all distances (can’t get distorted up close)

Question 4

How can we improve text Legibility and Readability?

Answer 4

• adapt text alignment to user perspective e.g. rotate to where the user is facing
• improve the contrast between foreground and background to ensure visibility
• render over good (typically flat) surface e.g. table or wall

Question 5

virtChallenges related to awareness of reality?

Answer 5

• virtual environment blocking the real environment (obstacles , people around us and events coming up ) => can intrude our interaction with the virtual system
• how can we support awareness of reality (perhaps some AR? we don’t want to affect our perception though)

Question 6

Potential solutions to awareness of reality?

Answer 6

• augmented virtuality (bringing selective objects from the real world into our virtual environment)
• having a constrained play area (boundaries of safe space)

WITH ALL OF THESE THINK HOW IMMERSION AND PRESENCE IS AFFECTED!

Question 7

Challenges related to physical area?

Answer 7

The physical world occupies a limited space, while the virtual world can be infinite, setting a play area will further limit the space virtually. How can we map the virtual and physical environment in a way that they will match while keeping the immersion aspect?

Question 8

Potential solutions?

Answer 8

• translational gain e.g. 1m of movement in reality is 4m in virtual environment
• redirected walking - trick brain into thinking we are walking in a straight line somehow - creating infinite virtual distance when walking in a circle
• teleportation via ray casting
• input devices for controlling movement , we won’t ever have to physically move
• treadmills , preferably 360 to allow movement in all directions

Question 9

in conclusion what do we need to think about when making 3D environments?

Answer 9

• input techniques that reduce technique
• visual cues that gives us awareness of the physical world
• locomotion techniques to allow movement in a constrained space

always think about how immersion and presence is affected.