[WIP] Dual out to single shutterglass signal conversion
Posted: Wed Aug 26, 2009 11:48 pm
Hi all, I've got some interesting ideas for you...
The ultimate goal of this project is to take a dual projector 3d output signal and get a single projector shutterglass output from it. Of course this means you could also use a CRT monitor. This would be a good project for people who want to use iZ3D's driver with shutterglasses without losing sync by using iZ3D's dual projector output selection instead of the shutterglass output. You'll see what I mean if you keep reading.
I don't know if I'll actually do this but someone else could use the ideas for their own version.
Reasons for doing it this way:
One problem with a passive polarization setup is that you need a special screen to preserve the polarization. If you don't want a special screen and just want to use your wall instead, then you should probably consider shutterglasses with a DLP projector.
Version 1: get a 3d signal to your dual projectors and block the light with shuttering LCD glass.
OK, I don't expect anyone to do this but it's good to explain it in order to get started with the ideas of the final version. The reason to not do it this way is because it will end up pretty dark and I expect not that good.
Note that you should use DLP projectors instead of LCD for various reasons.
For this version, just setup your 2 projectors and block each one with LCD glass that is connected to the shutterglass signal. This should block each beam alternatively in sync with your glasses so that when your left eye is clear, only the left projector image is hitting the wall. When your right eye is clear, only the right projector image is hitting the wall. This should work but is awkward because you need bigger LCD glass to block the projectors and not overheat and not leak much light. Of course the two projectors' refresh rate should be EXACTLY the same and also EXACTLY in sync with each other. I've tested this and it IS possible to perfectly sync two monitors in either Clone or Dual Monitor modes although it's possible some cards/setups could have problems. I guess you should try to verify this capability before you embark on this project although most people won't have the hardware to test it. I can talk more about testing later. You can use E-D Activator to turn on your glasses if your dongle is connected to the #1 monitor. iZ3D must be used in Dual monitor mode and not Clone mode if I am correct. For now, on to Version 2.
Version 2: like Version 1 but don't use LCD shutters on the projectors.
OK, so for this version, take out the LCD shutters on the projectors and insert a box before each projector's VGA-in cable. This project uses analog signals but maybe someone could adapt it to digital. The box has circuitry that, when activated, blacks out alternating frames of video for every other refresh. This mimics the function of the LCD glass that was removed but does not have the downsides like dimming or overheating. The blanking generated by the two boxes must be 180 degrees out of phase and can be triggered by the shutterglass signal or else just activated with a switch and you would have a 50/50 chance of being out of phase. Cycle the switch if it's out of phase or else build in a parallax inversion switch or use Ctl-F8 with iZ3d's driver. On to the final version.
Version 3: take signals for the two projectors and combine them into one output for one DLP projector or CRT monitor.
Now design another circuit that can switch VGA input signals with each refresh so that you get one output. Send this to one DLP projector and it should work. I guess you could skip the blanking circuit and just make the switching circuit. Now you can use iZ3D's driver with shutterglasses and never lose sync. Hurray. You might need to use Ctl-F8 to do field inversion occasionally between cutscenes or something but not if you used the shutterglass signal to help trigger the video signal swapping properly. I suppose I should have just skipped to version 3. OK, sorry. Anyway, I think this is an awesome idea and wouldn't be surprised if others had thought of it before me but I haven't seen it anywhere so I thought I'ld post it myself. Please point me to it if you know of any other threads that would help with this project.
Hopefully this is a project that will appeal to people like RageDemon and QuadropoeniX. (hint hint)
Later.
The ultimate goal of this project is to take a dual projector 3d output signal and get a single projector shutterglass output from it. Of course this means you could also use a CRT monitor. This would be a good project for people who want to use iZ3D's driver with shutterglasses without losing sync by using iZ3D's dual projector output selection instead of the shutterglass output. You'll see what I mean if you keep reading.
I don't know if I'll actually do this but someone else could use the ideas for their own version.
Reasons for doing it this way:
One problem with a passive polarization setup is that you need a special screen to preserve the polarization. If you don't want a special screen and just want to use your wall instead, then you should probably consider shutterglasses with a DLP projector.
Version 1: get a 3d signal to your dual projectors and block the light with shuttering LCD glass.
OK, I don't expect anyone to do this but it's good to explain it in order to get started with the ideas of the final version. The reason to not do it this way is because it will end up pretty dark and I expect not that good.
Note that you should use DLP projectors instead of LCD for various reasons.
For this version, just setup your 2 projectors and block each one with LCD glass that is connected to the shutterglass signal. This should block each beam alternatively in sync with your glasses so that when your left eye is clear, only the left projector image is hitting the wall. When your right eye is clear, only the right projector image is hitting the wall. This should work but is awkward because you need bigger LCD glass to block the projectors and not overheat and not leak much light. Of course the two projectors' refresh rate should be EXACTLY the same and also EXACTLY in sync with each other. I've tested this and it IS possible to perfectly sync two monitors in either Clone or Dual Monitor modes although it's possible some cards/setups could have problems. I guess you should try to verify this capability before you embark on this project although most people won't have the hardware to test it. I can talk more about testing later. You can use E-D Activator to turn on your glasses if your dongle is connected to the #1 monitor. iZ3D must be used in Dual monitor mode and not Clone mode if I am correct. For now, on to Version 2.
Version 2: like Version 1 but don't use LCD shutters on the projectors.
OK, so for this version, take out the LCD shutters on the projectors and insert a box before each projector's VGA-in cable. This project uses analog signals but maybe someone could adapt it to digital. The box has circuitry that, when activated, blacks out alternating frames of video for every other refresh. This mimics the function of the LCD glass that was removed but does not have the downsides like dimming or overheating. The blanking generated by the two boxes must be 180 degrees out of phase and can be triggered by the shutterglass signal or else just activated with a switch and you would have a 50/50 chance of being out of phase. Cycle the switch if it's out of phase or else build in a parallax inversion switch or use Ctl-F8 with iZ3d's driver. On to the final version.
Version 3: take signals for the two projectors and combine them into one output for one DLP projector or CRT monitor.
Now design another circuit that can switch VGA input signals with each refresh so that you get one output. Send this to one DLP projector and it should work. I guess you could skip the blanking circuit and just make the switching circuit. Now you can use iZ3D's driver with shutterglasses and never lose sync. Hurray. You might need to use Ctl-F8 to do field inversion occasionally between cutscenes or something but not if you used the shutterglass signal to help trigger the video signal swapping properly. I suppose I should have just skipped to version 3. OK, sorry. Anyway, I think this is an awesome idea and wouldn't be surprised if others had thought of it before me but I haven't seen it anywhere so I thought I'ld post it myself. Please point me to it if you know of any other threads that would help with this project.
Hopefully this is a project that will appeal to people like RageDemon and QuadropoeniX. (hint hint)
Later.