baker@csl.dl.nec.com (Larry Baker) (05/08/91)
Does anyone have any references for computer-generated holography? Please mail responses if possible, I will summarise - I don't always have time to pursue the net, and our groups expire quickly. Thanks, Larry -- -- Larry Baker NEC America C&C Software Laboratories, Irving (near Dallas), TX baker@texas.csl.dl.nec.com cs.utexas.edu!necssd!baker
will@rins.ryukoku.ac.jp (will) (05/09/91)
In article <1991May7.215514.6676@csl.dl.nec.com>, baker@csl.dl.nec.com (Larry Baker) writes: >Does anyone have any references for computer-generated holography? > The following is from previous postings on this subject: wiml@milton.acs.washington.edu: There was a "how to" article on this in the Apr-May 1990 issue of Circuit Cellar Ink ('issue 14'). The author managed to generate holograms by taking a picture of his VGA screen and photoreducing it, but it should be possible to photoreduce, say, laser printer output and get better results from having more dots ... Last time this topic came up (around Apr-May 1990) there was some source code posted to do the calculation. I didn't save any of it, however. From halazar@media-lab.MEDIA.MIT.EDU Sat Jan 12 13:17:17 1991: Taking a momentary break from the ol' thesis to answer this repeated and nagging question, "What about those computer generated holograms, anyway?", he dived in.... ALL 94% OF YOU EVER WANTED TO KNOW ABOUT COMPUTER GENERATED HOLOGRAMS A hologram is a medium that records the direction and intensity of light, in contrast to a photograph, which only records light's intensity. Typically, the holographic material (usually a high resolution photosensitive emulsion) records an interference pattern caused by the simultaneous exposure of two sources of coherent light: one reflected from the object being imaged, the other directly from a reference or carrier beam. This interference pattern is such that if the developed hologram is placed in the original reference beam, light is diffracted or reflected in such a way that the original object appears to float in space at its original location. The spatial relationship between the viewer and objects in the scene appears identical in "real life" and in the hologram. More complicated holographic processes can produce white-light illuminable, even multi-color holograms. Computer generated holograms replace the objects in the scene with synthetic objects. Presently, two major types of computer generated holograms exist. The first, and the most difficult to produce, is commonly called a CGH (computer generated hologram; yes, brace yourself for confusion). CGHs are made by calculating the interference patterns to be recorded on the holographic plate by first figuring out what part of the synthetic object is visible from what part of the hologram, then summing the phase and amplitude of the light that each part of the object reflects. For interesting objects, this calculation must be performed for many points on the hologram because the spatial frequencies range from 100-1000 fringes per millimeter. Recording the information onto the holographic medium is also a problem; for CGH optical elements, for instance, the pattern is often recorded using an electron beam writer. Although computing fringe patterns may seem like the obvious way to make computed holograms, the technique is impractical for large, complicated, static images. CGH is computationally viable for simple or repetitive interference patterns, such as optical elements. Computing fringe patterns is also useful for dynamic holography (or holographic video). In MIT's system, data from a memory store is converted to an analog signal and used to modulate an acoustic signal emitted from a transducer. This transducer is coupled to an optical crystal in which the sound waves form compression patterns capable of diffracting light. A small crystal can be used to "sweep out" a large diffractive area. The diffractive pattern in memory is a holographic fringe pattern, currently computed at up to several frames per second (for simple wireframe objects) using a 16K processor Connection Machine 2. The memory store is the CM2's framebuffer. However, the image size is still quite small (3x3x3 cm) usable volume updated at 40Hz, I'd guess), and complicated objects take a long time to compute. High quality synthesized display holograms are almost exclusively produced using a technique known as holographic stereography. If a hologram is analogous to a window onto the original scene, then a stereogram is a series of many slit small windows, each only big enough horizontally to fit the pupil of the viewer's eye when the viewer stands up next to the plate. Instead of a view onto a 3D scene, each little window has information about a single, 2D projection of that scene. These projections can be created using a moving cinema camera or standard polygonal or raytracing computer graphics program. The different views are computed by moving the camera, with its lens axis always facing perpendicular to the camera's direction of travel, horizontally through the view zone. A new image of the scene is captured every pupil's width or so. To make the stereogram, these images are projected using laser light onto a diffusion screen, and a vertical slit of a holographic plate is exposed to the screen and to a reference beam. The geometrical relationship of the slit to the projection screen is the same as the relationship between the camera and its plane of focus when the view for that slit was captured. So when the hologram is illuminated, a viewer looking through the plate actually looks through two different slits, and thus sees to different image perspectives, the same ones that would have been seen were the viewer really looking at the object. A second hologram, called a transfer hologram, is commonly used to allow the viewer to stand some distance from the stereogram. The transfer hologram is actually a hologram of the slit hologram. When illuminated, the transfer hologram projects an image of the slits of the master hologram out into space, so the viewer can easily step into the master plane without suffering facial lacerations. Because images are only captured side to side, the stereogram exhibits only horizontal parallax: vertical viewer motion doesn't change the appearance of the subject. The holographic stereogram has a lot going for it. The input perspectives are relatively easy to produce using widely available computer graphics techniques. In general, interesting and realistic graphics hacks look even more interesting and realistic in a stereogram. Only about 100 perspective images need to be generated for a standard 20x25cm (8x10") stereogram. Transfer holograms can be made in full, vibrant color, with a little work. Size is almost unlimited; with a little cleverness, a rig that would fit in a suburban garage could crank out life size computer images of Miatas. Fringe-pattern-type CGHs just aren't anywhere near as convenient, useful, or satisfying, and won't be for quite a while. But, sadly, only a handful of places in the world can make stereograms, and even fewer know how. Most of them are research facilities, like our group. The rest are usually involved in mass production or commissioned work so its tough unless your images or data is really cool. A full, high quality stereogram lab costs about $500 thousand. And the holography market is hardly booming. The technology almost exists for a holographic printer computer peripheral, which would open the world of low cost (couple dollars a page), high quality 3D hardcopy to many more people, but no one wants to put much money into it. You'd think the 1 meter square computer generated hubcaps in the basement would convince somebody.... So the short answer is, "No, it isn't hard to compute a holographic image. It's really hard, however, to make it into a hologram." Unless you'd like to be a lab sponsor, that is. --Michael Halle Spatial Imaging Group MIT Media Lab mhalle@media-lab.media.mit.edu HOPE THIS HELPS. William Dee Rieken Researcher, Computer Visualization Faculty of Science and Technology Ryukoku University Seta, Otsu 520-21, Japan Tel: 0775-43-7418(direct) Fax: 0775-43-7749 will@rins.ryukoku.ac.jp
rick@pangea.Stanford.EDU (Rick Ottolini) (05/09/91)
IMHO digital holography will be THE 3-D graphics technique of the future. Current rendering techniques SIMULATE 3-D through the using of lighting models, shape [perspective, stereo], and motion [fly-thru animation, virtual reality animation]. Holography seeks to compute actual light waves themselves. I envision "Princess Lea" displays, floating images like that of the help message in Star Wars I. This avoids the sensory sheaths the VR people are using. The mathematics of digital holography are fairly well known, but the computations are expensive. They are similar to other imaging mathematics such as my field of seismic imaging. Even with all kinds of shortcuts thrown in, it will take billions to trillions of calculations per second to display interesting holographic images. With the computing speeds increasing an order of magnitude every five years and no end in sight, we are taking about the early 21st century for this capability. The Popular Science article of last year equates the complexity of MIT Media Lab holo-images with 2-D graphics on oscilloscopes 30 years ago. So this technology is probably realizable in most readers lifetimes. As pointed out in an early posting, much work still has to be done in the display hardware, that is getting the numerical description of the light waves converted into light.
tmb@ai.mit.edu (Thomas M. Breuel) (05/10/91)
In article <1991May9.153446.21742@leland.Stanford.EDU> rick@pangea.Stanford.EDU (Rick Ottolini) writes:
IMHO digital holography will be THE 3-D graphics technique of the future.
Current rendering techniques SIMULATE 3-D through the using of lighting
models, shape [perspective, stereo], and motion [fly-thru animation,
virtual reality animation]. Holography seeks to compute actual light waves
themselves. I envision "Princess Lea" displays, floating images like that
of the help message in Star Wars I. This avoids the sensory sheaths the
VR people are using.
Digital holography will probably eventually have its place. However,
holography is still bound by the laws of optics. If something comes in
between you and the holographic screen, the screen cannot project
beyond the obstacle. Likewise, the appearance of an object floating in
front of a hologram is only maintained if you are looking at the
hologram; you cannot have an object float "above", say, a table if you
are looking at it "from the side".
The requirements of virtual reality go further, and it remains to be
seen whether any practical solutions can be found that do not require
the user to wear goggles.uselton@nas.nasa.gov (Samuel P. Uselton) (05/10/91)
In article <1991May9.153446.21742@leland.Stanford.EDU> rick@pangea.Stanford.EDU (Rick Ottolini) writes: >IMHO digital holography will be THE 3-D graphics technique of the future. >Current rendering techniques SIMULATE 3-D through the using of lighting >models, shape [perspective, stereo], and motion [fly-thru animation, >virtual reality animation]. Holography seeks to compute actual light waves >themselves. As a tray racer, I mean ray tracer, I've thought a bit on this, and have a little experience too. >I envision "Princess Lea" displays, floating images like that >of the help message in Star Wars I. This avoids the sensory sheaths the >VR people are using. >The mathematics of digital holography are fairly well known, but the computations >are expensive. Probably more than you realize. >They are similar to other imaging mathematics such as my field >of seismic imaging. I've also consulted with "Big Oil". Seismic imaging is more similar to image processing and scene analysis than to image generation techniques. You HAVE the image, and are trying to guess the most likely scene which could have created it. >Even with all kinds of shortcuts thrown in, it will take >billions to trillions of calculations per second to display interesting >holographic images. Current realistic image synthesis techniques can take from 100 million to 1 billion operations per image. Laser holography is AT LEAST a couple of orders of magnitude more. And you still WANT the animation so add another one or two orders of magnitude. I see trillions of operations per second as a LOWER bound on what it might take. The NAS project at NASA Ames regards pushing industry into producing a teraflops computer by the year 2000 as a "Grand Challenge" problem. It'll be quite a while longer before that capacity finds its way into workstations for the broad market. >With the computing speeds increasing an order of magnitude >every five years and no end in sight, ^^^^^^^^^^^^^^^^^^^ There is a growing number of "experts" pointing out limits to current hardware techniques that we ARE rapidly approaching. We need BREAK-THROUGH improvements in technology, not just incremental improvements in the technology we have now. >we are taking about the early 21st >century for this capability. Proof of concept maybe. To get the image quality you want, the speed you'll want, and the cost to make it usable by someone other than national labs, I think it'll most likely be after 2030. >The Popular Science article of last year equates >the complexity of MIT Media Lab holo-images with 2-D graphics on oscilloscopes 30 >years ago. So this technology is probably realizable in most readers lifetimes. Some yes. Most? That depends as much on health technology as anything. >As pointed out in an early posting, much work still has to be done in the >display hardware, that is getting the numerical description of the light waves >converted into light. That too. Sam Uselton uselton@nas.nasa.gov employed by CSC working for NASA (Ames) speaking for myself
halazar@media-lab.media.mit.edu.MEDIA.MIT.EDU (Michael Halle) (05/11/91)
"Rendering with/like holography" (more correctly, rendering at the light wave level) is a little like building macroscopic structures out of individual molecules: sure, you could imagine doing it, and with enough effort you could, but in the general case you might be able to think of a better way. In a similar way, natural phenomena can be considered solely in terms of quantum effects, but classical mechanics generally work pretty well and are much less painful. What level of realism are you trying to achieve that would require such accuracy? It's a lot of work to go to just to spatially quantize to x by y (by z?) pixels. The display (and the eye itself) usually define the reasonable limits. Perceptual restrictions are *always* an issue in display. Sure, computing holograms can be expensive. Holograms (usually) contain more information than do two-dimensional images, so computing them *should* take longer. And the expense of the calculation is proportional to the stupidity of the approach (and not linearly, either), especially if you're a purist and insist on diffraction limited three-dimensional images. But if you make those tradeoffs like they taught ya in engineerin' school and don't do more work than you have to, computation time for 3-D images might be only, say, ten times that for 2-D images. And you might be able to actually make holograms instead of dreaming about them. (And a previous poster was right; unless there's some physics that we don't know about, mid-air projection of 3-D images, with no display material in front or behind, is right out.) Here's a little thought question that may shead some light on the comutation question: What is the intrinsic information content of a pure sine wave oscillating at an arbitrarily high frequency? Think about the relative costs of the different ways of producing such a sine wave. Would your answer differ if the signal were specified to be analog or digital? Michael Halle Spatial Imaging Group MIT Media Laboratory mhalle@media-lab.media.mit.edu
rick@pangea.Stanford.EDU (Rick Ottolini) (05/11/91)
In article <1019.282B28FD@nwark.fidonet.org> Samuel.P..Uselton@p0.f13.n391.z1.fidonet.org (Samuel P. Uselton) writes: >Newsgroups: comp.graphics > >In article <1991May9.153446.21742@leland.Stanford.EDU> rick@pangea.Stanford.EDU (Rick Ottolini) writes: >>They are similar to other imaging mathematics such as my field >>of seismic imaging. > I've also consulted with "Big Oil". Seismic imaging is more similar > to image processing and scene analysis than to image generation > techniques. You HAVE the image, and are trying to guess the most > likely scene which could have created it. I represent Big Oil. Seismics is my business and graphics an avocation. The two disciplines use approximately the same universe of algorithms, but in different porportions. The cross-fertilization of ideas is fruitful. >>Even with all kinds of shortcuts thrown in, it will take >>billions to trillions of calculations per second to display interesting >>holographic images. > Current realistic image synthesis techniques can take from 100 million > to 1 billion operations per image. Laser holography is AT LEAST > a couple of orders of magnitude more. And you still WANT the animation > so add another one or two orders of magnitude. I see trillions of > operations per second as a LOWER bound on what it might take. > The NAS project at NASA Ames regards pushing industry into producing > a teraflops computer by the year 2000 as a "Grand Challenge" problem. > It'll be quite a while longer before that capacity finds its way > into workstations for the broad market. A typical seismic imaging algorithm that took 100,000 seconds in the early 1970s takes about a second these days. Two orders of magnitude are due to smarter algorithms and three orders of magnitude are due to that my desktop RS/6000 is a thousand times faster than my old PDP-11/34. These improvements will continue for both seismics and graphics. >>With the computing speeds increasing an order of magnitude >>every five years and no end in sight, > ^^^^^^^^^^^^^^^^^^^ > There is a growing number of "experts" pointing out limits to current > hardware techniques that we ARE rapidly approaching. I've heard this doom and gloom for the past 15 years and remain unconvinced. "Breakthroughs" aren't always obvious when they start. There is enough stirring in the pot now to keep us occupied for a long time.
Samuel.P..Uselton@p0.f13.n391.z1.fidonet.org (Samuel P. Uselton) (05/11/91)
Newsgroups: comp.graphics In article <1991May9.153446.21742@leland.Stanford.EDU> rick@pangea.Stanford.EDU (Rick Ottolini) writes: >IMHO digital holography will be THE 3-D graphics technique of the future. >Current rendering techniques SIMULATE 3-D through the using of lighting >models, shape [perspective, stereo], and motion [fly-thru animation, >virtual reality animation]. Holography seeks to compute actual light waves >themselves. As a tray racer, I mean ray tracer, I've thought a bit on this, and have a little experience too. >I envision "Princess Lea" displays, floating images like that >of the help message in Star Wars I. This avoids the sensory sheaths the >VR people are using. >The mathematics of digital holography are fairly well known, but the computations >are expensive. Probably more than you realize. >They are similar to other imaging mathematics such as my field >of seismic imaging. I've also consulted with "Big Oil". Seismic imaging is more similar to image processing and scene analysis than to image generation techniques. You HAVE the image, and are trying to guess the most likely scene which could have created it. >Even with all kinds of shortcuts thrown in, it will take >billions to trillions of calculations per second to display interesting >holographic images. Current realistic image synthesis techniques can take from 100 million to 1 billion operations per image. Laser holography is AT LEAST a couple of orders of magnitude more. And you still WANT the animation so add another one or two orders of magnitude. I see trillions of operations per second as a LOWER bound on what it might take. The NAS project at NASA Ames regards pushing industry into producing a teraflops computer by the year 2000 as a "Grand Challenge" problem. It'll be quite a while longer before that capacity finds its way into workstations for the broad market. >With the computing speeds increasing an order of magnitude >every five years and no end in sight, ^^^^^^^^^^^^^^^^^^^ There is a growing number of "experts" pointing out limits to current hardware techniques that we ARE rapidly approaching. We need BREAK-THROUGH improvements in technology, not just incremental improvements in the technology we have now. >we are taking about the early 21st >century for this capability. Proof of concept maybe. To get the image quality you want, the speed you'll want, and the cost to make it usable by someone other than national labs, I think it'll most likely be after 2030. >The Popular Science article of last year equates >the complexity of MIT Media Lab holo-images with 2-D graphics on oscilloscopes 30 >years ago. So this technology is probably realizable in most readers lifetimes. Some yes. Most? That depends as much on health technology as anything. >As pointed out in an early posting, much work still has to be done in the >display hardware, that is getting the numerical description of the light waves >converted into light. That too. Sam Uselton uselton@nas.nasa.gov employed by CSC working for NASA (Ames) speaking for myself
eugene@nas.nasa.gov (Eugene N. Miya) (05/11/91)
In article <1991May9.153446.21742@leland.Stanford.EDU> rick@pangea.Stanford.EDU (Rick Ottolini) writes: >IMHO digital holography will be THE 3-D graphics technique of the future. >Current rendering techniques SIMULATE 3-D through the using of lighting >models, shape [perspective, stereo], and motion [fly-thru animation, >virtual reality animation]. Holography seeks to compute actual light waves >themselves. >I envision "Princess Lea" displays, floating images like that >of the help message in Star Wars I. This avoids the sensory sheaths the >VR people are using. I just happened to glance this. Two points. 1) I am a little bit disturbed by the special effects Star Wars image. 2) I don't think it will be "THE" but it will certainly be a powerful technique. I think part of the effectiveness is dependent upon the audience (who pays the bucks and what their background expectations are). This film (SW) seems to be THE image of what we think holography might be. I hope not. We have some fundamental human limitations with our eye balls. Retinas are flat. We need to look (no pun intended) at what we want in 3-D (and 4-D). Things like depth cues, superposition information, etc. But it fundamentally does not get rid of problems like hidden objects. You can't see what's behind Leah, she obscures it. That's not good. You won't be able to see behind that 3-D rendering of an oil reservoir without doing something else (head parallax, time varying (or not) cross-sections, etc.) This costs is computation time, storage, etc. I still think we will need ball-and stick models, computer generated CAD-type 3-D sculpture outputs, sounds, etc. But, holography might be helped if optical benches, and analogy and digital optical computer were cheaper and available. Computing one pixel or voxel at a time is inefficient. I do think its neat, we should fund it, and we should have lots of people playing with holograms. Hell, I have holograms sitting on my desk. I just don't think it will be the end-all of computer graphics. --eugene miya, NASA Ames Research Center, eugene@orville.nas.nasa.gov Resident Cynic, Rock of Ages Home for Retired Hackers {uunet,mailrus,other gateways}!ames!eugene
npw@eleazar.dartmouth.edu (Nicholas Wilt) (05/11/91)
In article <1991May10.165256.12414@nas.nasa.gov> uselton@nas.nasa.gov (Samuel P. Uselton) writes: >In article <1991May9.153446.21742@leland.Stanford.EDU> rick@pangea.Stanford.EDU (Rick Ottolini) writes: >>Even with all kinds of shortcuts thrown in, it will take >>billions to trillions of calculations per second to display interesting >>holographic images. > Current realistic image synthesis techniques can take from 100 million > to 1 billion operations per image. Laser holography is AT LEAST > a couple of orders of magnitude more. And you still WANT the animation > so add another one or two orders of magnitude. I see trillions of > operations per second as a LOWER bound on what it might take. > The NAS project at NASA Ames regards pushing industry into producing > a teraflops computer by the year 2000 as a "Grand Challenge" problem. > It'll be quite a while longer before that capacity finds its way > into workstations for the broad market. >>With the computing speeds increasing an order of magnitude >>every five years and no end in sight, > ^^^^^^^^^^^^^^^^^^^ > There is a growing number of "experts" pointing out limits to current > hardware techniques that we ARE rapidly approaching. We need > BREAK-THROUGH improvements in technology, not just incremental > improvements in the technology we have now. What about massively parallel architectures? If digital holography techniques are as trivially parallelizable as ray tracing, then you don't even need any bandwidth between nodes. Sure there are issues (load balancing and stuff). That's just software. _Lots_ of people are working on better software for parallel architectures. >>The Popular Science article of last year equates >>the complexity of MIT Media Lab holo-images with 2-D graphics on oscilloscopes 30 >>years ago. So this technology is probably realizable in most readers lifetimes. > Some yes. Most? That depends as much on health technology as > anything. The hardware guys specialize in disproving statements like this. > >Sam Uselton uselton@nas.nasa.gov >employed by CSC working for NASA (Ames) speaking for myself --Nick npw@eleazar.dartmouth.edu
eugene@nas.nasa.gov (Eugene N. Miya) (05/13/91)
In article <1991May11.152915.6488@dartvax.dartmouth.edu> npw@eleazar.dartmouth.edu (Nicholas Wilt) writes: >In article <1991May10.165256.12414@nas.nasa.gov> uselton@nas.nasa.gov (Samuel P. Uselton) writes: >>In article <1991May9.153446.21742@leland.Stanford.EDU> rick@pangea.Stanford.EDU (Rick Ottolini) writes: >>>With the computing speeds increasing an order of magnitude >>>every five years and no end in sight, >> ^^^^^^^^^^^^^^^^^^^ >> There is a growing number of "experts" pointing out limits to current >> hardware techniques that we ARE rapidly approaching. We need >> BREAK-THROUGH improvements in technology, not just incremental >> improvements in the technology we have now. > >What about massively parallel architectures? >techniques are as trivially parallelizable as ray tracing, then you don't >even need any bandwidth between nodes. > >Sure there are issues (load balancing and stuff). That's just software. >_Lots_ of people are working on better software for parallel architectures. >The hardware guys specialize in disproving statements like this. You have three things working here. 1) Do not trivialize the software problem. If the problem was simple, it would have been solved in 1968. Similar to the "automatic programming" problem of the 1950s. 2) Every body has all these graphics codes in sequential languages. The future dusty decks. We are either going to have to throw out all of this code, and rewrite, or have some awfully good software. 3) Parallel architectures are an O(n) (or at best (n^2)) solution to problems that many times have greater complexity. This is why students should take computing theory classes. We can only rely on so many hardware improvements. Got to rememebr we compute in the physical (real, not virtual) world. Start reading and reasing issues in comp.arch (although few architects read that group any more). There are some ends in sight. Those components (that software) which runs fastest and most reliable are those which aren't there. --Gordon Bell "It's the things that nobody knows anything about that we can discuss..." --R.P. Feynman --eugene miya, NASA Ames Research Center, eugene@orville.nas.nasa.gov Resident Cynic, Rock of Ages Home for Retired Hackers {uunet,mailrus,other gateways}!ames!eugene
aipdc@castle.ed.ac.uk (Paul Crowley) (05/13/91)
In article <1991May13.045426.7871@nas.nasa.gov> eugene@amelia.nas.nasa.gov (Eugene N. Miya) writes: >3) Parallel architectures are an O(n) (or at best (n^2)) solution to >problems that many times have greater complexity. This is why students >should take computing theory classes. Yeah, what we really need is quantum mechanical computers! (Quantum mechanical computers do different bits of the calulation in different eigenstates. Essentially, they can fork every millisecond without limit. The hard part is combining the results at the end, since it's probabilistic. Theoretically possible it is, "feasable" wouldn't be my choice of wording... ____ \/ o\ Paul Crowley aipdc@castle.ed.ac.uk \ / /\__/ Part straight. Part gay. All queer. \/
rick@pangea.Stanford.EDU (Rick Ottolini) (05/14/91)
In article <1991May10.235611.18365@nas.nasa.gov> eugene@amelia.nas.nasa.gov (Eugene N. Miya) writes: >This film (Star Wars) seems to be THE image of what we think holography might be. >I hope not. We have some fundamental human limitations with our >eye balls. Retinas are flat. We need to look (no pun intended) at >what we want in 3-D (and 4-D). Things like depth cues, superposition >information, etc. But it fundamentally does not get rid of problems >like hidden objects. You can't see what's behind Leah, she obscures it. >That's not good. You won't be able to see behind that 3-D rendering of >an oil reservoir without doing something else (head parallax, time >varying (or not) cross-sections, etc.) This costs is computation time, >storage, etc. I prefer to think of digital holography as a RENDERING method not a MODELING method. As rendering, we would compare DH to the current methods of lighting models, etc. and the sensory sheaths of virtual reality. IHMO DH may be better. As to modeling, I am not implying that DH has to be "realism". We can pull apart objects, create fantasties that are physically unrealizable.
rick@pangea.Stanford.EDU (Rick Ottolini) (05/14/91)
I started inquiries into digital holography about 15 months ago because of a project I wanted to try. I wanted to make a "floating earth globe" holo for the 20th anniversary of Earth Day. I have the model data and few spare terra-flops, but didn't know how easy it was to generate the hologram.
will@rins.ryukoku.ac.jp (will) (05/14/91)
In article <1019.282B28FD@nwark.fidonet.org>, Samuel.P..Uselton@p0.f13.n391.z1.fidonet.org (Samuel P. Uselton) writes: > The NAS project at NASA Ames regards pushing industry into producing > a teraflops computer by the year 2000 as a "Grand Challenge" problem. > It'll be quite a while longer before that capacity finds its way > into workstations for the broad market. > From what I have seen and heard (from the people doing this research) this technology should be availible to the government and big industries by 1997 (and maybe by 1995) and into the home a few years later. As I have been told, the biggest problem now is not making teraflop computers, but manufacturing techniques must be updated for production and quality control standards must be updated for mass prod. The reason cited was that these computers use components that require more advanced manufacturing technologies and that current facilities must be redesigned to meet these requirements. A little side note: I was once told that another reason for the delay of the teraflop technologies was that: All of the Corporations that make computers and have these technologies currently cannot just release it at this time even if they could. The reason is "Economics". They and thier customers have invested billions in current technolgy. To make it absolutly obsolete over night would destroy there companys. Not to forget that many of these manufacturers have warehouses full of new equipment ready to be sold. Worth billions. This is one reason that companies do incremental scaling of computer technologies. To get as much money as possible with as small an investment as possible. It's all "Economics". Will...
will@rins.ryukoku.ac.jp (will) (05/14/91)
In article <1991May10.235611.18365@nas.nasa.gov>, eugene@nas.nasa.gov (Eugene N. Miya) writes: >You can't see what's behind Leah, she obscures it. >That's not good. You won't be able to see behind that 3-D rendering of >an oil reservoir without doing something else (head parallax, time >varying (or not) cross-sections, etc.) This costs is computation time, >storage, etc. > Eugene, I completly disagree. The fact that Leah is obscured is most important for graphics like scientific visualization. Such as the oil reservoir problem. If your computer can produce such an image it won't make any difference about the extra costs of computation time and data storage. Other algorithms such as for transparency, etc will handle the rest. >I still think we will need ball-and stick models, computer generated CAD-type >3-D sculpture outputs, sounds, etc. But, holography might be helped if >optical benches, and analogy and digital optical computer were cheaper >and available. Computing one pixel or voxel at a time is inefficient. Agreed, ball and stick models will always have their place. >I just don't think it will be the end-all of computer graphics. Also agreed, I don't think that holograms will be the end thing. Their are so many ways that data must be shown for humans to get the most of it. Besides, once the hologram problems are solved, we will most likly as is always the case find new methods as good or better. Research is never ending. There is always a place for new ideas. Will....
mark@calvin..westford.ccur.com (Mark Thompson) (05/15/91)
In article <268@rins.ryukoku.ac.jp> will@rins.ryukoku.ac.jp (will) writes: > A little side note: I was once told that another reason for the delay > of the teraflop technologies was that: > All of the Corporations that make computers and have these > technologies currently cannot just release it at this time even > if they could. The reason is "Economics". They and thier > customers have invested billions in current technolgy. To make > it absolutly obsolete over night would destroy there companys. > Not to forget that many of these manufacturers have warehouses > full of new equipment ready to be sold. Worth billions. I would believe this argument in a heartbeat for US auto manufacturers but I find it a little hard to swallow for high tech computer companies. Any company that could advance the state of the art by a few magnitudes would do so instantly (provided it was cost effective), with the hope of annihilating the competition and reaping massive profits. High tech computer companies generally don't wharehouse huge masses of systems because of the cost and the volatility of the high-end market. Today's Mega-Monster Number Smasher is tommorrow's doorstop. %~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~% % ` ' Mark Thompson CONCURRENT COMPUTER % % --==* RADIANT *==-- mark@westford.ccur.com Principal Graphics % % ' Image ` ...!uunet!masscomp!mark Hardware Architect % % Productions (508)392-2480 (603)424-1829 & General Nuisance % % % ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
falk@peregrine.Sun.COM (Ed Falk) (05/16/91)
In article <10210@castle.ed.ac.uk> aipdc@castle.ed.ac.uk (Paul Crowley) writes: > >Yeah, what we really need is quantum mechanical computers! > >(Quantum mechanical computers do different bits of the calulation in >different eigenstates. Essentially, they can fork every millisecond >without limit. No way! It would be a nightmare to program. Every try to draw an eigen state diagram? -ed falk, sun microsystems sun!falk, falk@sun.com In the future, somebody will quote Andy Warhol every 15 minutes.