Requirements


Based on the assumptions of the project settings, we want to address small teams up to six users. The chosen display technology is projection-based. We could identify hard measurable requirements which can be evaluated and soft requirements as e.g. usability which only qualitatively evaluated, e.g. they can be compared with existing single user systems or components.

The following figure gives an overview of the requirements grouped by topic:

Requirement Description
Views The amount of individual perspective correct views which have to be generated for a stereoscopic 3D system. It is obviously twice the amount of users.
Image Frequency The frequency with which the user perceives each view/eye such that a temporal steady image perception is enabled
Brightness per View The brightness which is perceived at the users eyes. The brightness is directly depending on the luminance on the screen surface attenuated with the shutter glass transmission ratio.
Image Resolution The resolution in regard to eye resolution at a specific distance.
Contrast The min/max contrast considering all optical components
Display System Usability The maintainability of the system. Setup and relocation times. Number of individual components. The base line is the usability of a set of single user systems for each user.
Space per User Ergonomic minmum space requirements for team work in projection systems based on empiric observation and literature values.
Ergonomic Workplace Can the system easily be integrated in a work environment. Lightning conditions. The base line is the usability of a set of single user systems for each user.
Tracking Targets The amount of rigid bodies which can be tracked in 6 degrees of freedom. Should take into account head tracking and a individual interaction device.
Tracking Volume The volume which can be tracked with given accuracy
Tracking Rate/Latency The measurement rate to reach interactive rates (which defines the minimal latency). Absolute latency depends on all processing steps.
Tracking Accuracy The spatial accuracy in mm and degrees for all 6 degrees of freedom for a given setting
Tracking Robustness Influence of noise as external lighting or occlusion.
Tracking Usability The base line is the usability of a set of single user systems for each user. Robustness is here an important measure which has an impact on usability.
Pointing Device Usability The base line is the usability of existing devices. Additionally the identifiability of the device has to be guaranteed
Navigation Device Usability The group navigation device should be able to easily suggest the navigation functions and should be accessible by each participant equally.
Multi-User Engine The Application Runtime Engine has to be able manage up to 10 (or more even user)
Framerate per User The application and rendering framerate has to be interactive that is normally above 20 Hz.
Usability Image Generator The image generation hardware should be able to be easily maintained and consist of commodity hardware. This is easily achieved by combining as much graphics cards as possible in a single host computer,
A1: Placement Planning The requirements for the application system are to detailed to be included here they are governed in the application specification. It is include for reference and completeness. The general requirements are that the desired functionality can be developed with the uses engines.
A2: Design Review The requirements for the application system are to detailed to be included here they are governed in the application specification. It is include for reference and completeness. The general requirements are that the desired functionality can be developed with the uses engines.

Goals


The following values are desirable to be achieved and are derived from the sections above.

  min max
Views 6 20
Image Frequency [Hz] 60 >
Luminance per View [cd/m*m] 100 >
Image Resolution [% eye] (1) 30% >
Contrast [min/max] 1:1000 >
Display System Usability o +
Space per User o +
Ergonomic Workplace o +
Tracking Targets 20 >
Tracking Volume [m x m x m] 5x3x2 >
Tracking Rate/Latency [Hz]/[ms] < 50/33
Tracking Accuracy [mm]/[°] < 5/1
Tracking Robustness + +
Tracking Usability o +
Pointing Device Usability o +
Navigation Device Usability o +
Multi-User Engine 6 >
Framerate per User [Hz] 30 >
Usability Image Generator o +
A1: Placement Planning o +
A2: Design Review o +
  • >: higher is better,
  • <: less is better
  • +: better than existing single user setup
  • o: as good as existing single user setup
  • -: worse than existing single user setup
  • considering also the amount of user
  • (1) Eye Resolution [arg min]