Share live music
28 MPixels on screen
More encompassing field of view: The human brain uses its visual system for detecting when it is in motion. This sensation is strongest when there is motion in the peripheral vision. Our dome is constructed to cover a FoV (field of view) of about 1800 horizontal and 1450 vertical, which covers nearly the entire human visual field. This area is about 4x larger than the FoV available in the best HMDs.
Higher resolution: Our dome uses three 4K (2060p) projectors plus two 2K (1080p) projectors, giving a total of 28MPixels on screen. Most commercially available HMDs display on the order of 1 Mpixel per eye.
Communal experience: Sharing live music can be enjoyable.
Our goal at VMS is to create alternate visual realities - to allow the viewers to visit other worlds. The OVC-3D supports several types of display systems. We built a 12 foot diameter dome at the studio to experiment with this type of environment. Domes do not generate the same level of immersion as the HMDs (head mounted displays like the Rift or Vive) - the audience retains an awareness that they are in a room watching a show rather than feeling that they are actually in this other world. The stereoscopy for HMDs is also better. But domes do have some advantages over HMDs:
We ended up designing and building the dome and projection system ourselves, as we did not like either the prices we were getting or the quality of the images from commercial vendors. VMS is not in the business of building domes, so we are happy to share some info about our system.
Our dome is constructed from a 12ft diameter fiberglass shell. This was the largest size that would fit in our loft with 13 foot ceilings, and allows several people to simultaneously sit/work within the hemisphere with >1800 FoV. We considered constructing a rear-projection system, but it needed a solid clear acrylic shell, which could not be brought into our space.
We used 5 front projectors to provide adequate luminance as well as to provide higher resolution. We experimented with spherical mirrors, but found the resolution was uneven in ways that worked against using multiple projectors.
We did not implement stereoscopic projection. We experimented with various polarization schemes and chroma notch filters and found that they did not work well if the FoV was more than 1100. We decided that unobstructed viewing of the full 1800 was more important than the stereoscopy.
Our key innovation was to use custom home-theatre projectors. A $4K high-end home theater projector can provide better resolution and contrast ratio than the $30K projector designed for this type of professional work. We selected the JVC ILA projector series for the high static contrast ratio and 4K e-Shift technology. We had to use a Navitar wide-angle lens affixed to a custom mounts that we machined in order to achieve a short enough throw-distance. We also had to do some internal modifications to the projector air-flow to support vertical mounting.
30 degree from vertical mounting: The dome is mounted 30 degrees from vertical, which allows lean back viewing, but also viewing by a standing musician.
4ftW x 6ftT x 1.5ft deep working area within hemisphere: At the center front of this area, a single musician gets about 1900 horizontal FoV by 1450 vertical FoV, plus full arm motion without shadows. Larger groups can view the dome but the FoV may be reduced.
Projector layout: Horizontal projectors cover the center, top, and bottom of the dome with vertical projectors on either side.
28M projected pixels: Three JVC D-ILA 4K projectors at the center projecting 8M pixels each, while 2 JVC D-ILA without the 4K support handle the sides. The actual number of usable pixels is reduced by about 25% due to overlap and off-edge pixels. The projectors provide 80K:1 static contrast ratios.
High reflectance surface coating: We used a highly directional screen coating, which provided a brighter image and greater rejection of cross reflection. However, this makes the luminance balance at the seams between projectors depend on the viewing angle, so we might trim back a bit the next time.
Physical: Optically sealed environment; raised working platform; dual 11,000 cfm intake/exhaust fans for projector ventilation.
Projection mapping: We used Scalable Display Technology's EasyBlend SDK.
Rendering systems: Each projector is driven by a separate PC with an Intel Core I7 CPU and Nvidia graphics cards (670s on the sides, 980ti elsewhere)
Central manager: A separate PC for controlling the system runs the VMS recording/editing software with four 1080p displays, and provides direct control over each projector configuration via a LAN interface.
Ventilation:Two 5000cfm acoustically isolated fans remove heat from the enclosed dome area.