Head-Fixed, Edge Fixed, World-Fixed Texts
By Yuanbo Li, 2023 Spring
The Three Texts Presentations
A group of scientists from the University of Regensburg in Germany conducted a research study to examine the impact of different text presentation types and locations in virtual reality (VR). The study focused on three specific types of text presentations: head-fixed, edge-fixed, and world fixed.
The original paper can be found here. This page mainly serves as an introduction of the work and summary of the results.
1)head-fixed:
refers to a text displayed in a head-up display, where the text maintains a static position and orientation relative to the user's head movements. This can include text that remains stationary in both position and orientation, text with a fixed position but dynamic orientation that adjusts to the user's head movements, or text with a dynamic position but static orientation.
2)edge-fixed:
involves a text with a static position and dynamic orientation, where the text is attached to the virtual environment at an edge and vertically tilts to face the user. This type of presentation allows the text to maintain a connection with the environment while adapting its orientation to ensure readability.
3) world fixed:
refers to a static, in-situ text that is placed within the virtual environment. This type of text remains stationary and integrated into the virtual world, providing a consistent reference point for the reader.
Results
The researcher found each of the presentations are helpful at different scenaiors. Here is a summary of the pros and cons of each technique.
1)head-fixed:
Pros:
Reading while moving and exploring: Participants can read while walking and looking at other works in the virtual museum.
Simultaneous viewing of pictures and text: Participants expressed that this condition made it easier to match the text with the corresponding picture since they could look at both simultaneously.
Cons:
Cumbersome view of whole text: the text obstructed too much of their field of view, making it harder to switch between reading and looking at the picture.
2)edge-fixed:
Pros:
Comfortable and aesthetically pleasing reading: Participants found the paragraph presentation type with edge-fixed location to be the most enjoyable way of reading during the study.
Optimal viewpoint: The technique provided participants with an optimal viewpoint to the text regardless of their angle, allowing them to simultaneously view the painting and read the text without difficulties.
Cons:
Proximity requirement: Some participants mentioned that they still needed to stay closer to the text and look at it to read effectively.
3) world fixed:
Resemblance to a real museum: Participants perceived the virtual museum with world-fixed text paragraphs as similar to a physical museum, creating a realistic experience.
Simplicity and ease of understanding: The design of the virtual museum allowed participants to quickly grasp how it worked, enhancing usability and reducing the learning curve.
Skimming capability: Participants found that they didn't need to read the entire text in the world-fixed condition. Skimming the text for keywords was sufficient to complete the task, potentially saving time and cognitive effort.
Cons:
Lack of interactivity: Participants may desire the ability to move the text, allowing for more freedom to explore the virtual environment while reading.
Implementation
For students who may wish to implement the three different text presentation techniques, here is a simple guide of how to do it in Unity VR.
Head-Fixed text:
You can find the tutorial here.
Edge-Fixed text:
Unfortunately, the paper does not discloses its implementation of head-fixed texts. And non tutorials can be found online. I'm still searching for it.
World-Fixed text:
It is simply adding a TextMeshPro object in the world space.