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Means of the Virtual Reality

Evgenie Rudometov, Victor Rudometov.

Article is grounded on book substances "the PC Architecture, accessories, multimedia" —  SPb: Peter, 2000, 416 with.

Systems of 3D-maps

The systems realising effect of volume maps, exists for a long time already. Some decades the arrangements using stereoslides are known. Also various points with colour glasses — red-dark blue, red-green were popular . On sale it was possible to find albums with geometrical stereofigures, by the way, very facilitating process of studying of stereometry in school. There were appropriate art albums with stereophotos which could be considered through similar points. In Europe in the seventieth years colour TVs in which arrangement the special time delay lines leading to offset of red colour on the map have been provided have been released even. Affirmed, that at review of teleprograms on such arrangement through colour points, it is marked psevdostereeffekt. But computer processing techniques develop and on change to those old and primitive enough arrangements have come new, computer, allowing to realise the high-grade volume map with excellence and clearness.

Now there are the different systems VR providing reception of the high-quality three-dimensional map, for example, well-known systems CrystalEyes PC, 3D Max, CyberMaxx 3D, i-Glasses, VFX1 and others. In a basis of operation of these and similar systems some major principles of creation three-dimensional (3D) maps are necessary.

The first and the cheapest consists in image generation in turn for the left and right eye. Thus both maps are in turn output on the uniform screen of the screen monitor. Sharing of maps, is fulfilled by means of the special high-speed locks by turns overlapping a stream of maps, formed on the screen monitor screen. Operation of such locks is clocked with the output map and consists in serial closing of the map of the screen of the screen monitor for eyes of the spectator. As such locks in the first developments the mechanical arrangements reminding locks in cameras, however present time used, as a rule, use LcD-zatvornye lenses on the liquid crystals, controlled a special clock card. Such lenses are usually fulfilled in the form of points through which the user looks at the screen monitor screen. Glasses of such points by turns become opaque, than and sharing of the map for eyes is reached.

One of the main difficulties at such way of output — low frequency of vertical scanning — personnel frequency of screen monitors. Modern ergonomic requirements of frequency of vertical scanning of the screen monitor provide, as is known, at least, not less than 70 Hz, however are recommended — 100 Hz. The lower case way of image generation on the screen monitor screen (NI) thus should use. Non-observance of these requirements leads to fast fatigue of eyes from a map blinking. To a low bound which should make not less than 70 Hz, satisfy the majority of modern screen monitors. To frequency of 100 Hz — better, and therefore and more expensive arrangements. This all usual, that is, in this case, to the unary map. For double, the stereo, maps is required frequency of vertical scanning twice above — 150-200 Hz. To this requirement satisfy only the most qualitative and very expensive screen monitors.

On the specified principle of creation of stereomaps following models of output devices of the visual information — points are constructed, for example : CrystalEyes PC, 3D Stereo Set, 3D Max, CyberMaxx 3D, Holographic3D.

The given models provide good enough stereomap with frequency of 60 Hz at usage of the screen monitor with frequency of vertical scanning of 120 Hz. To this level there correspond only good and rather not cheap screen monitors! However it is necessary to mark, what even in case of usage of such screen monitors, frequency of the stereomap does not satisfy even to minimal requirements.

The second principle — more difficult and, as a rule, more expensive in implementation. Consists in usage as a part of system of output of the visual information of two separate arrangements — on one for each eye. Simultaneously each of these arrangements forms the map: one — for the left eye, the second — for right. Sharing of maps is provided with a system construction.

Still in the late sixties in a number of technical journals results of development by IBM of systems of output of the visual information from the COMPUTER in the form of 3-dimensional stereomaps have been published. Appropriate programs and arrangements have been developed. At the heart of those systems two methods of creation of the stereomap laid. The first is usage of light-guides for transmission for each eye separately of a video information generated by two displays on cathode-ray tubes — ELT: 2 ELT — 2 light-guides — 2 eyes. The second is an application of two miniature displays on ELT, built in in a special helmet and allocated opposite to eyes, separately for each eye.

Systems on the basis of the big or miniature displays on ELT and light-guides did not differ in low cost and compactness. Development of computer processing techniques and appearance of high-performance units have allowed to reduce considerably dimensions and to reduce cost.

For examples of such systems of output of the visual information the arrangements using as units of video output colour LCD-displays — displays on liquid crystals can be . It, for example, such systems as i-Glasses and VFX1, received is enough wide circulation. Two colour LCD-displays, a part of each of these systems, carry out video output for each eye simultaneously, but separately. It provides reception of stereomaps enough excellence.

I-Glasses Represents the compact arrangement providing output of a video information through two desksize LCD-displays, a part of the given arrangement which fastens on a forehead. The construction i-Glasses provides separate and independent feed of video maps from LCD-displays. Video signal for i-Glasses in standard NTSC. It allows to use the given arrangement not only as the computer 3D-screen monitor, but also as a prefix to the TV or the videorecorder for individual review of video programs.

One of the most successful models of systems of a computer human interface is VFX1. This arrangement is developed by known Forte corporation. In basis VFX1 it is put shlemopodobnyj the design possessing many advantages. In VFX1 LCD-displays with rather quite good permission use. The user looks through adjustable optics. All it creates illusion of the big screen. For effect reaching 3D on each LCD-screen of helmet VFX1 through the special interface appropriate video signal from the computer is dispatched: separate for left LCD and separate for right LCD. Special resources of tracing inspect position of a head of the user and permanently enter this information into the computer. Head turn in a helmet corresponds to head turn in the virtual world. The helmet has built in high-quality speakers and a microphone.

The systems providing output of 3D-maps, — i-Glasses and VFX1 have generated variety of arrangements with higher parametres. As an example it is possible to result i-glasses X2 and i-glasses ProTec from i-O Display System. VFX3D represents improved version VFX1.

The number pikselov has increased in one and a half time – with 180,000 to 230,000, colour is supported 16 and 24-bit, we will combine with all last 3D accelerators, the permission to 1024х768 with various frequency of upgrade uses USB. More perfect system of orientation uses.

Except Forte corporation the helmets have released Virtual Research, n-Vision, Sony, Philips.

Despite obvious progress in the field of perfection of systems of 3D-maps, some experts, consider, that the future behind the laser arrangements providing projection of the colour 3D-map is direct on retinas of both eyes. Such researches are already carried on, and affirms, that results are quite successful.


As is known, the first sound cards were 8-bit and used FM-synthesis. The greatest distribution was received by sound cards Sound Blaster of company Creative Technology. However the first generation of sound cards presented by 8-bit arrangements, could not provide excellence of a sound, especially for VR. It has been linked by that the dynamic range of such maps corresponded to level of cassette tape recorders of low quality — 40-45 db. Really, 8 bits provide 256 levels of a signal. Besides, it is necessary to consider features of conversion therefore dynamic level 40-45 db — it is completely not bad for 8-bit cards. Considerably to raise quality it was possible only at the expense of transition to 16-bit cards providing a dynamic range close to level of CD. Improvement of quality of sound cards was promoted also by changeover of method FM by method Wave Table.

For support of working capacity before the released programs sound cards should provide compatibility with company Creative Technology cards Sound Blaster as a result of which operation has appeared a number of standards de facto. Usually compatibility with Sound Blaster is reached at the expense of hardware or program emulation.

All modern sound cards are 16-bit arrangements. Such cards provide a high-quality sound with a wide frequency range (20 Hz-20 kgts at non-uniformity of an amlitudno-frequency response characteristic 0 db), high value of a relation a signal noise (to 90 db, but usually 65-80 db), small nonlinear distortions (less than 1 %) etc .

The sound can be one-channel — a mode "mono" or two-channel — a mode "stereo". Accordingly and processing is carried out or on one channel, or on two.

Unlike one-channel, the two-channel binaural sound allows to handle space layout of sources of a sound. This effect is provided at the expense of an appropriate difference in phases between signals of channels. Thus a difference in phases – in an initial signal! However the high-grade stereoeffect is reached only in the limited space which value is defined by two audio systems raying a sound – stereo speakers. The sound extends from the given two audio systems. It is feature of a binaural sound.

For VR qualities of a binaural sound obviously insufficiently. Multi-channel sound systems are required. Beep in multi-channel system possesses difficult phase structure. It allows to realise a space sound. Sound sources "are not locked" between two audio systems, and freely distributed in all environing space, of course, according to the original, or nearly so. In such systems the sound can extend extensively, it "is not anchored" to stereo speakers. For implementation of a space sound — a 3D-sound there are different ways and systems.

The most obvious, logically simple and, possibly, the most correct is an application of multi-channel writing and multi-channel playback. Some (4 and more) channels of strengthening and some (4 and more) audio systems in this case use.

However usage of several identical sound channels often is not expedient for the economic and technical reasons. In this case apply different ways of coding and conversion of the sound information.

One of the most powerful systems of sound coding — system Dolby Surround Sound. The given system is widely applied in cinema, a television, a sound recording. This system uses, for example, in DVD CD-ROM. Quality of a sound in such and similar systems — very high.

For rise of subjective quality of a binaural sound there are various systems of the processing, allowing to receive a 3D-sound. Thus even its cloning leads to essential improvement of quality.

For sound improvement of quality the systems grounded on application of special processors of processing of beeps use. Some sound maps incorporate the given chips. Such maps can play back a sound both in a stereo mode, and in a mode 3D. Quality of a sound in such systems in a mode 3D often above, than in a traditional mode of stereosounding is subjective. The sound becomes more volume (3D), better. And it is often provided with only two audio columns. Though there are systems with three audio columns and even more. Certainly, quality in such systems still above. But, it is necessary to mark at once, that quality of a 3D-sound essentially depends not only on a hardware of sound maps, but also from the accompanying software. Certainly, some deformations of a space picture of layout of sources of a sound (sometimes it and is inevitable) are possible, but it is frequent is not an essential lack.

The combined variants providing both coding, and usage of the special processors, special chipsets, and also multi-channel amplifiers, stereo speakers, filters, the specialised software etc. are possible also .

The sound cards intended for information processing for the purpose of creation of a high-quality 3D-sound, generate the big streams of figures with which traditional buses ISA do not consult. For this reason the steady tendency of changeover of sound cards with bus ISA on arrangements with bus PCI was outlined. Now cards of this type are already dominating on the computer market. As an example of such cards it is possible to result Monster Sound MX300 from Diamond Multimedia and Sound Blaster Live! (SB Live! Full — the complete version, SB Live! Value — the version with the reduced functions) from Creative Labs.

The keyboard, the joystick, the mouse, track-bol, the 3D-mouse, gloves.

As information input devices in the computer in the elementary cases the traditional keyboard uses. It is quite admissible in many applications, for example, in information retrieval systems, and also in games.

To raise speed of input of the information in many cases special input devices allow. As such arrangements joysticks can be used, for example. They quite often use in various simulators and in games. In the elementary cases the joystick -it a crandle possessing several degree of freedoms. It allows to enter simple commands into the program: " Forwards "," back "," on the left "," to the right "etc . Modern joysticks can be extremely difficult and expensive arrangements. Their cost can make hundreds US dollars and even more. Perspective arrangements are the joysticks supporting processing technique Force Feedback. Usage of the given processing technique allows to realise a principle of a power feedback for the given arrangements. Processing technique Force Feedback is built in in DirectX 5.0 and above. Joysticks Force Feedback provide more complete cloning in games and various simulators. Such arrangements provide transmission of vibrations where it is required under the scenario, they"resist ", shiver" etc.

And it is finite, frequent as input devices such arrangements, as mice (mouse) use. There are different mice: with two buttons, three buttons etc . As a rule, — it is enough two buttons . Besides, mice happen wire and without wires. Wireless mice provide the raised comfort. By means of similar arrangements link with the computer is carried out distantsionno, for example, by means of an infrared radiation. This emanation, by the way, is well mirrored from obstacles, for example, as a rule, well mirrored from room walls where the computer is allocated. For the specified purposes probably application of a radio communication. Radio band usage allows to increase range and to raise dependability. It is necessary to carry necessity of periodic charging of the standalone power supply to lacks of wireless mice — the secondary generator. This operation some hours are necessary to fulfil everyone. For this purpose usually the mouse is located in the special container which has been hooked up, as a rule, to port of the computer.

In last time became popular a track-boly (track ball), the turned mice represent. Handle is carried out by ball rotation (ball) and pressing corresponding a key. When at hand there is no rug or he could not be put, for example, handle is carried out from far otstojashchego from seat desktop, such arrangements — are convenient, their maintenance — is expedient. In other cases — on the fan.

All enumerated arrangements actively use in the programs, operating two and three-dimensional objects on the plane screen of the screen monitor and in the conditions of VR. That is they are the same necessary arrangements, as well as points, and helmets. However for handle of program objects in the conditions of high-grade VR, as much as possible approximated on perception to existing, environing, material, that is real, to the world, sometimes it is not enough possibilities of the given arrangements. To some extent enumerated arrangements limit moving to world VR. Certainly, first of all it concerns semiprofessional and professional usage of possibilities VR for solution enough challenges.

To expand possibilities of input of the information in the computer such arrangements, as three-dimensional mice — 3D-mouse allow, for example . Arrangements of this type are according to the destination similar traditional (2D) to mice. However unlike usual, 3D-arrangements are capable to watch their space moving and the information on it to enter into the computer. For an example of the similar arrangement can be wireless GiroMouse Dimond corporations. On desktop it will work as the usual mouse (2D) and if to lift and press the button on the underplate it is possible to use this arrangement in air (3D). Data exchange between the mouse and the base arrangement which has been hooked up to the computer, is carried out in a radio band.

As the arrangement providing cloning of touch, it is possible to result mouse FEELit Mouse. By means of the given arrangement it is possible to feel a relief of the map or, for example, convexity of the button, having led over them the cursor, and also object weight at its moving. It is necessary to mark, all it becomes a reality only in the presence of appropriate programs.

Other arrangement expanding possibilities VR, special gloves — gloves are . They allow according to requirements of maintained programs to carry out information input in the computer by means of various manipulations with hands, paintbrushes of hands, fingers. For example, specifying to a finger on the object in VR it is possible to call any operations: object moving in VR, change of its sizes, colours, forms etc . The object can be compared with the object in VR in the real world. So it is possible to exercise administration from VR. In the long term with the help gloves output of the tactile information - tactile sensations - firm, soft, cold, hot etc. will be carried out . These are difficult and expensive arrangements. It is enough to mark that fact, that gloves, intended for professional application, have some hundreds sensors: expansions, compression, movings etc . These sensors fix and gauge space movings, as joint – a shoulder, a hand, a paintbrush, so each selected point separately - each finger, each phalanx. Thus it is necessary to consider, gauge and enter each curving, each turn into the computer.

Possibilities VR in solution of a wide range of applied tasks substantially depend on parametres of input\output devices. Therefore to development of the given resources the big attention is paid. In process of development of computer processing techniques functionality of hardware-software resources of the interface providing link of the user and the computer (information input-output) in the conditions of VR, permanently increase.

It is published in log "you and your computer"


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