sutherla@qtp.ufl.edu (scott sutherland) (05/26/89)
I have a question concerning the "compatability" of the double- buffering used in the X-specs 3D glasses (and others, like the SEGA 3D glasses) and an interlaced screen. My reason for asking this question is simple. I recently received my Turbo Silver SV upgrade, where the SV stands for stereo vision (or something equivalent). Now I can render my favorite animations in stereo. I also purchased the SV adaptor for use with X-Specs and/or SEGA glasses. (I haven't gotten my 3D glasses yet, as the best price I can find for the SEGA glasses is $50) However, I render most of my animations in interlace so that I can record them to VHS tape at a later date (when I get my encoder or genlock, another of the many things on my wish list). So my question is as follows: I believe that the stereo is accomplished by double buffering two "copies" of the images being viewed. Each buffer is one of the two stereo images. I believe that the "switching rate" is ~30Hz. So each of the two stereo images is on the screen 1/60th of a second. Now the apparent problem. An interlaced screen takes 1/30th of a second to be totally displayed. So the "standard" 30 Hz rate won't work. So what happens? Does the hardware/ software combination compensate and slow down to 15Hz? I would think that this would be an unacceptable rate, since the flicker in the X-Specs glasses is only somewhat tolerable at 30 Hz. (I have tried Space Spuds and the molecular modelling stuff with X-Specs, and the flicker of everything but the screen is most annoying) So, does anyone out there on the 'net know what happens in this situation? Does X-Specs and its software even support interlace? The answer to these and many other questions will help me in my quest for "fantastic" stereo ray-traced animations!! Thanks, Scott Sutherland
karl@sugar.hackercorp.com (Karl Lehenbauer) (05/28/89)
Speaking for Hackercorp, we do not believe it is possible to show 400-line images and have an acceptable flicker rate with the 3D glasses. -- -- uunet!sugar!karl | "Woof!" -- free Usenet access: (713) 438-5018
wade@pnet01.cts.com (Wade Bickel) (05/29/89)
As you suspected, it is impossible to use the glasses in interlaced
mode. Depending on which piece of software you are using, trying to utilize
interlaced mode will achieve varing results.
I believe that if you use M3D with interlaced pictures you will get
a double height picture in each view. i.e. you will see the top half of the
picture stretched to full screen height. I wrote a version of M3D that
checked for this and sliced out every other line, but I'm pretty sure this
did not go out (v1.06).
As far as flicker goes, it really is desireable to dim the room
lighting if possible. While the screen flickering is generally not to
irritating even in bright non-florecent lighting, as you pointed out, the
rest of the world will flicker annoyingly while the glasses sync to the
screen, and more significantly the edges of the monitor will create an un-
wanted frame of reference if you bring images out of the screen.
Also, you will want to keep in mind that if you want to put your
images on video-tape for (future) stereo viewing, you will defeat your VCR's
interlaced output just as you do with the current Amiga output.
Good Luck,
Wade.
PS: With any luck a fairly comprehensive X-Specs support library should be
released by Haitex any day now. It is done and tested so???
Also, given that the Impulse/Sega glasses combo run about the same as the
XSpecs glasses, why would you buy Sega? XSpecs are clearly superior.
Disclaimer: these opinions are mine and mine alone. I have no affiliation
with Haitex Resources, Inc., other than that I used to work there.
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INET: wade@pnet01.cts.comhugh@censor.UUCP (Hugh D. Gamble) (05/30/89)
In article <4268@crash.cts.com>, wade@pnet01.cts.com (Wade Bickel) writes: > > As you suspected, it is impossible to use the glasses in interlaced > mode. Depending on which piece of software you are using, trying to utilize > interlaced mode will achieve varing results. ... > UUCP: {nosc ucsd hplabs!hp-sdd}!crash!pnet01!wade > ARPA: crash!pnet01!wade@nosc.mil > INET: wade@pnet01.cts.com How about support for new modes provided by the Enhanced Chip Set to provide high resolution b/w 3D? (or maybe 2 bitplane). Might be good for "serious" applications no? -- Hugh D. Gamble (416) 581-4354 (wk), 267-6159 (hm) (Std. Disclaimers) hugh@censor, kink!hugh@censor # It may be true that no man is an island, # but I make a darn good peninsula.
ewhac@well.UUCP (Leo 'Bols Ewhac' Schwab) (06/01/89)
In article <563@orange6.qtp.ufl.edu> sutherla@orange6 (scott sutherland) writes: > I have a question concerning the "compatability" of the double- >buffering used in the X-specs 3D glasses (and others, like the SEGA 3D >glasses) and an interlaced screen. [ ... ] ...I render most of my >animations in interlace so that I can record them to VHS tape at a later >date [ ... ] > I assume when you say this you mean you render it in 400 lines. >An interlaced screen takes 1/30th of a second to be totally displayed. So >the "standard" 30 Hz rate won't work. So what happens? Does the hardware/ >software combination compensate and slow down to 15Hz? [ ... ] You will not be able to see all 400 lines of either the left or right eye image when viewing the images in stereo. If the software is at all smart, you'll see every other line, so the picture will still be intelligible (not vertically stretched). Unless you plan to view these images flat, there's no need to render them with 400 lines. If you wish to turn on video interlace (for VCR recording, for example), you can use a PD program called 'SetLace'. This will cause all new screens and the WorkBench screen to start jittering away. Gawd, I really should write a short book on this subject... _-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_ Leo L. Schwab -- The Guy in The Cape INET: well!ewhac@ucbvax.Berkeley.EDU \_ -_ Recumbent Bikes: UUCP: pacbell > !{well,unicom}!ewhac O----^o The Only Way To Fly. hplabs / (pronounced "AE-wack") "Work FOR? I don't work FOR anybody! I'm just having fun." -- The Doctor
wade@pnet01.cts.com (Wade Bickel) (06/03/89)
hugh@censor.UUCP (Hugh D. Gamble) writes: >In article <4268@crash.cts.com>, wade@pnet01.cts.com (Wade Bickel) writes: >> >> As you suspected, it is impossible to use the glasses in interlaced >> mode. Depending on which piece of software you are using, trying to utilize >> interlaced mode will achieve varing results. >... > >How about support for new modes provided by the Enhanced Chip Set >to provide high resolution b/w 3D? (or maybe 2 bitplane). >Might be good for "serious" applications no? Hmmm... I must not understand the statement/question. The library (which has not been released yet) should work fine with the Enhanced Chip Set and the new modes. In fact, it works with interlace, it just ends up being displayed funny because the XSpecs drivers are switching at 60 hz and the interlaced screen is switching at 30 hz. Thanks, Wade. UUCP: {nosc ucsd hplabs!hp-sdd}!crash!pnet01!wade ARPA: crash!pnet01!wade@nosc.mil INET: wade@pnet01.cts.com