Swept-volume Display - Drawbacks


Known volumetric display technologies also have several drawbacks that are exhibited depending on trade-offs chosen by the system designer.

It is often claimed that volumetric displays are incapable of reconstructing scenes with viewer-position-dependent effects, such as occlusion and opacity. This is a misconception; a display whose voxels have non-isotropic radiation profiles are indeed able to depict position-dependent effects. To-date, occlusion-capable volumetric displays require two conditions: (1) the imagery is rendered and projected as a series of "views," rather than "slices," and (2) the time-varying image surface is not a uniform diffuser. For example, researchers have demonstrated spinning-screen volumetric displays with reflective and/or vertically diffuse screens whose imagery exhibits occlusion and opacity. One system created HPO 3-D imagery with a 360-degree field of view by oblique projection onto a vertical diffuser; another projects 24 views onto a rotating controlled-diffusion surface; and another provides 12-view images utilizing a vertically oriented louver.

So far, the ability to reconstruct scenes with occlusion and other position-dependent effects have been at the expense of vertical parallax, in that the 3-D scene appears distorted if viewed from locations other than those the scene was generated for.

One other consideration is the very large amount of bandwidth required to feed imagery to a volumetric display. For example, a standard 24 bits per pixel, 1024×768 resolution, flat/2D display requires about 135 MB/s to be sent to the display hardware to sustain 60 frames per second, whereas a 24 bits per voxel, 1024×768×1024 (1024 "pixel layers" in the Z axis) volumetric display would need to send about three orders of magnitude more (135 GB/s) to the display hardware to sustain 60 volumes per second. As with regular 2-D video, one could reduce the bandwidth needed by simply sending fewer volumes per second and letting the display hardware repeat frames in the interim, or by sending only enough data to affect those areas of the display that need to be updated, as is the case in modern lossy-compression video formats such as MPEG. Furthermore, a 3-D volumetric display would require two to three orders of magnitude more CPU and/or GPU power beyond that necessary for 2-D imagery of equivalent quality, due at least in part to the sheer amount of data that must be created and sent to the display hardware. However, if only the outer surface of the volume is visible, the number of voxels required would be of the same order as the number of pixels on a conventional display. This would only be the case if the voxels do not have "alpha" or transparency values.

Read more about this topic:  Swept-volume Display

Other articles related to "drawbacks, drawback":

Session Jam - Drawbacks
... An example Mr ... Abdul Karim was a student of geology (four-year bachelor course) admitted to the university in the year 2000 (July) ...
List Of Pakistani Intelligence Agencies - Federal Investigation Agency - Law Enforcement Services - Drawbacks
... Salaries Benefits and FIA employees draw very poor salaries and other benefits for them that’s why corruption cannot be controlled in Pakistan. ...
CJ Carella's Witch Craft - System
... Drawbacks can then be used to gain extra points ... Other Qualities and Drawbacks are of a Supernatural sort and are used to designate a character as a particular type of character (Gifted, Bast, Spirit, and so on) or ...
United States House Committee On Commerce And Manufactures - History and Jurisdiction
... Requests for drawbacks, refunds authorized when imported goods on which duties had been paid were re-exported, were similarly referred to the committee during ... were received from merchants and others who had been denied drawbacks for a variety of reasons ... Merchants in Philadelphia, for example, asked for a drawback on a shipment of sugar that had been destroyed before it left the port, while other petitioners, denied drawbacks because of late filing of their ...

Famous quotes containing the word drawbacks:

    France has neither winter nor summer nor morals—apart from these drawbacks it is a fine country.
    Mark Twain [Samuel Langhorne Clemens] (1835–1910)