Shared holographic experiences

Holograms don't need to stay private to just one user. Holographic apps may share spatial anchors from one HoloLens to another, enabling users to render a hologram at the same place in the real world across multiple devices.

What are shared holographic experiences?

Shared experience '''co-located''' '''collaboration''' example.
Shared experience '''co-located''' '''collaboration''' example.
Shared experience '''guidance''' scenario in the Skype app.
Shared experience '''guidance''' scenario in the Skype app.
Shared experience '''co-located''' and '''remote collaboration''' in the OnSight app
Shared experience '''co-located''' and '''remote collaboration''' in the OnSight app
Shared experience '''remote''' '''collaboration''' in the OnSight app.
Shared experience '''remote''' '''collaboration''' in the OnSight app.

While creating holographic experiences, developers and designers think about humans, who are at the center of the experience. The environment in which these humans will enjoy the experience and the objects that humans will interact with. Let's define what shared holographic experience is keeping these simple ideas in mind.

"A shared holographic experience is when two or more people are experiencing the same holographic object(s). It could be in the same or different environment(s)."

Defining your shared holographic experience scenario

Using the following set of simple questions, you can define your scenario for a shared holographic experience.

  1. How are they sharing?
  2. What is the group size?
  3. Where is everyone located?
  4. When are they sharing?
  5. How similar are their physical environments?
  6. What devices are they using?

Question 1: How are they sharing?

People can share experiences in several different ways and we will learn together and we grow in this space. To scope our discussions, let's use the following categories to define how people will be sharing the holographic experience.

  • Presentation: When the same content is being shown to several users.
    For example: A professor is giving out a lecture to several students using the same holographic material being presented to everyone. The professor however could have his/her own hints and notes that may not be visible to others.
  • Collaboration: When people are working together to achieve some common goals.
    For example: The professor gave out a project to learn about performing a heart surgery. Students pair up and create a shared holographic skills lab experience which allows medical students to collaborate on the heart model and learn.
  • Guidance: When one person is helping someone to solve a problem in a more one-one style interaction.
    For example: The professor giving guidance to a student when he/she is performing the heart surgery skills lab in the shared holographic experience.

The above concepts are important because they influence:

  • How people should consume the content?
  • Whether the control of objects needs to be considered?
  • Whether environmental factors need to be considered in your design?

Question 2: What is the group size?

Use the following broad categories to define your shared experience group size.

  • 1:1
  • Small < 7
  • Large >= 7

The numbers being used are simply recommended values from Microsoft experiences. Group size makes for an important question because it influences:

  • Representations of people in holographic space
  • Scale of objects
  • Scale of environment

Question 3: Where is everyone located?

Following categories help convey where users are located.

  • Co-located: All your users will be in the same physical space.
  • Remote: All your users will be in separate physical spaces.
  • Both: Your users will be a mix of co-located and remote spaces.

Some reasons why this question is crucial because it influences:

  • How people communicate?
    For example: Whether they should have avatars?
  • What objects they see. Are all objects shared?
  • Whether we need to adapt to their environment?

Question 4: When are they sharing?

Time of sharing is also an important question to ask when defining your scenario.

  • Synchronously: Sharing the holographic experience at the same time.
    For example: Two students performing the skills lab at the same time.
  • Asynchronously: Sharing the holographic experience at different times.
    For example: Two students performing the skills lab but working on separate sections at different times.
  • Both: Your users will sometimes be sharing synchronously but other times asynchronously.
    For example: Professor grading the assignment performed by the students at a later time and leaving notes for student for the next day.

Some reasons why this question is important because it influences:

  • Object and environment persistence.
    For example: Storing the states so they can be retrieved.
  • User perspective.
    For example: Perhaps remembering what the user was looking at when leaving notes.

Question 5: How similar are their physical environments?

If everyone in your shared holographic experience is not co-located, they could have very different experiences.

  • Similar: Environments that tend to have similar furniture, ambient light and sound, physical room size.
    For example: Professor is in lecture hall A and students are in lecture hall B. Lecture hall A might have fewer chairs than B but they both may have a physical desk to place holograms on.
  • Dissimilar: Environments that are quite different in furniture settings, room sizes, light and sound considerations.
    For example: Professor is in a focus room whereas students are in a large lecture hall filled with students and teachers.

It's important to think about the environment because it influences:

  • How will people experience these objects.
    For example: If your experience works best on a table and the user has no table? Or on a flat floor surface but the user has a cluttered space.
  • Scale of the objects.
    For example: Placing a 6 feet human model on a table could be challenging but a heart model would work great.

Question 6: What devices are they using?

Users could have different device categories when they join the shared experience.

  • 3D (mixed reality)
  • 3D (mixed reality and virtual reality)
  • 3D and 2D (mixed / virtual reality and phone or PC)

Applying the questions to define a shared holographic experience scenario

Using these questions we can now define the Holographic Academy Holograms 240 shared holograms scenario as:

A small, co-located group is synchronously collaborating on interacting with and placing an energy hub. Everyone has a similar physical environment and 3D mixed reality devices.

Sharing spatial anchors

The key to shared holographic experiences is multiple users seeing the same holograms in the world on their own device. One way to achieve shared anchors would be:

  • First the user places the hologram.
  • App creates a spatial anchor to pin that hologram precisely in the world.
  • App can then export this anchor and supporting tracking information to another HoloLens using a networking solution.
  • That shared anchor can now be imported by another HoloLens along with the supporting tracking data that lets that HoloLens locate the shared anchor in their world space.

With a shared spatial anchor, the app on each device now has a common coordinate system in which they can place content. Now the app can ensure to position and orient the hologram at the same location.

See also