Adjusting angle on a fluid-based prism to see dual 22"

[ghostface]

How much do I need to make the angle on my next prism to be able to see 3d at a normal distance from my desk and not really far back (like with this current prism)?

Double?

[Fredz]

I don't know if it's even possible, but you should be able to figure it by yourself by doing some calibration with known viewing distances and image sizes and with the use of the Snell's law. It's been a very long time since my last optics courses so I won't be more helpful than that I'm afraid... Or go for a physics or math teacher if you can find one nearby...

[cybereality]

I don't know much about prisms so I am not sure I can help you. So what exactly are you trying to accomplish? Mounting the prism to the desk and using it to view the 2 monitors in a parallel view configuration (sort of like a huge Holmes stereoscope)? What are the twin web-cams for?

[ghostface]

I don't know much about prisms so I am not sure I can help you. So what exactly are you trying to accomplish? Mounting the prism to the desk and using it to view the 2 monitors in a parallel view configuration (sort of like a huge Holmes stereoscope)? What are the twin web-cams for?

trying to view dual screen 3d with the iz3d driver at a regular distance from my desk

trying to take 3d pictures and video with the 2 hd 720p webcams

[Fredz]

As an approximation, I'd say that the viewing distance should be proportional to the angle of the prism since all the other values are constant (indice of refraction of the prism, size of the screens, interocular distance). So if you want to divide the viewing distance by a factor of two for example, I'd say you should halve the prism angle as shown in this schema :



But I'm not sure at all if it's really the case without doing the real calculations. And if the angle of the prism is too small it won't refract the light but reflect it, so you won't be able to see through it. This formula gives the minimum angle for a ray to be refracted and not reflected by a prism (where A is the angle of the prism and n is the indice of refraction) :
i = arcsin [n⋅sin(A - arcsin 1/n)]

You should be able to find the minimum A value for the angle of the prism using this formula, but you would first need to estimate the indice of refraction of the prism using the formula given in the schema and some known angles and distances to calculate i. Nothing really complicated since it's simple maths, but time consuming for sure...

[ghostface]

Thanks for the replies. I will try making a prism that has half the angle like you said. I'm not going to do the formula im just going to try it out because it's really quite easy to make because I have a dremel and it just melts the plastic.


Attached is my system info - I have an i7 950 and 2 GTS 450 cards in sli with 6gb ddr3 1600 memory.


Havent played many games in a while but I bought a bunch. Just tried out a game last night but I got HORRIBLE fps when I activated the iz3d driver. It worked perfectly otherwise but I think that my computer should be able to handle it better. I had turned off the 2nd monitor in the Nvidia control panel so I only rendered on my first screen just to test it out.

Why is this?

Does it have to do with the cpu or is there not enough graphics memory enabled by default? Should I overclock?

Should I lower the resolution?

[cybereality]

IZ3D does not have proper support for SLI. You might get better performance with only one card.

[ghostface]

IZ3D does not have proper support for SLI. You might get better performance with only one card.

This seems like its true but I didnt know it when I bought the cards. What am I supposed to do now? I just dropped over $1k on this system.

I could buy a GTX 580 if I REALLY had to in order to play the games on my list. If the GTS 450 is really screwing me then everything else I bought is worthless towards playing in 3d since the fps goes down to the single digits every time when I enable the iz3d driver even in old things like HL2 and TF2

I have also heard that GTA4 is really CPU dependant which is why I bought an i7 950 - is that what is bottlenecking me right now or is it the video card?

[cybereality]

Unfortunately stereo 3d drivers have always had horrible (or non-existent) support for SLI/CF. Only recently, like in the past year, did Nvidia finally offer SLI support on their driver. IZ3D and DDD do not, although IZ3D claims they are adding beta support in the DX10/11 codepath (although I have not heard this work for anyone yet). So I am pretty sure your problems are SLI related. You might want to just take one of the cards out and test it with the iz3D drivers again to make sure that is the problem. You can use an old game like HL2 to test it. However the GTS 450 is not that powerful on its own, so high-end games like GTA4 would probably not run too well in 3D (although if you set the graphics options to low it might work). Not sure how much luck you would have selling those cards, but you might get $75-100 a piece. Might be worth looking into getting a GTX 470, at the minimum, although a GTX 570 might be a better investment in the long run (since this is for a new rig, I presume).

[ghostface]

Unfortunately stereo 3d drivers have always had horrible (or non-existent) support for SLI/CF. Only recently, like in the past year, did Nvidia finally offer SLI support on their driver. IZ3D and DDD do not, although IZ3D claims they are adding beta support in the DX10/11 codepath (although I have not heard this work for anyone yet). So I am pretty sure your problems are SLI related. You might want to just take one of the cards out and test it with the iz3D drivers again to make sure that is the problem. You can use an old game like HL2 to test it. However the GTS 450 is not that powerful on its own, so high-end games like GTA4 would probably not run too well in 3D (although if you set the graphics options to low it might work). Not sure how much luck you would have selling those cards, but you might get $75-100 a piece. Might be worth looking into getting a GTX 470, at the minimum, although a GTX 570 might be a better investment in the long run (since this is for a new rig, I presume).

yup, disabling SLI worked really well. Now I hope the new glasses do too

[ghostface]

I wall mounted the monitors to get a few extra inches of space but the new glasses with the lower angle did NOT work.

I have to move back several feet to see the 3d but by then I miss out on details such as being able to read fine text.

[Fredz]

I wall mounted the monitors to get a few extra inches of space but the new glasses with the lower angle did NOT work.
I have to move back several feet to see the 3d but by then I miss out on details such as being able to read fine text.

What do you mean exactly by "did not work" ? Do you need to be farther than with the previous glasses ? Don't you see an image at all ? What angle did you choose for the prism ?

[cybereality]

I'm not going to do the formula im just going to try it out because it's really quite easy to make because I have a dremel and it just melts the plastic.

If you want to get something like this right you really have to do your homework. Don't worry, its mostly just trig (which is like junior high school level math).

[ghostface]

I wall mounted the monitors to get a few extra inches of space but the new glasses with the lower angle did NOT work.
I have to move back several feet to see the 3d but by then I miss out on details such as being able to read fine text.

What do you mean exactly by "did not work" ? Do you need to be farther than with the previous glasses ? Don't you see an image at all ? What angle did you choose for the prism ?

I wall mounted the monitors to get a few extra inches of space but the new glasses with the lower angle did NOT work.
I have to move back several feet to see the 3d but by then I miss out on details such as being able to read fine text.

What do you mean exactly by "did not work" ? Do you need to be farther than with the previous glasses ? Don't you see an image at all ? What angle did you choose for the prism ?

I made it at a distance of 10 millimeters instead of 19 in the original but i could not get a 3rd image to appear no matter what distance i was looking at. My reference video is a video sample file that I play in a stereoscopic player

It does work with the first pair, though. What i did was move my entire desk back about 1.5 feet and then i could converge the dual screens. Cant read small text on it tho

EDIT: nevermind, I got it to work by adjusting the colors more - the screen on the right is way brighter so I turned it down and adjusted the r/g/b and now it seems to meld together much easier than before with the old glasses. Great!

[Fredz]

So you are able to use your new glasses to see the two screens now ? At which distance from the screens do you stand now compared with your previous model ?

[ghostface]

So you are able to use your new glasses to see the two screens now ? At which distance from the screens do you stand now compared with your previous model ?

No. The new glasses didnt work at all so after working on them for over 2 hours I threw them away. The only ones I have are the first pair I made. _After_ wall mounting the screens which gave me a few extra inches from the screens to my eyes and then adjusting the brightness, contrast and RGB on the screens to make the picture/colors as similar as possible the result is that I can see the 3d very comfortably just by moving my desk or head back about 6"

its friggin sweet. I just have to put shutters on the glasses and then glue on an adjustable head strap that I took from some safety goggles to keep it tight.

[Fredz]

Ah ok, sorry it didn't work for your new glasses, I guess it came from the minimal angle of refraction that was too low, but we'll never know...

[cybereality]

Cool you got it to work. Is it comfortable to game from 6 feet back? I imagine the screen would look pretty small.

[ghostface]

Cool you got it to work. Is it comfortable to game from 6 feet back? I imagine the screen would look pretty small.

It works perfect at 52" away from the screen which is about 4.3 feet. I just pull my desk 6" back from where it usually is and its in position.

mounting on the wall gave me some more inches and matching the color definitely helped too. Im getting a GTX 570 tommorrow or the next day too.

[cybereality]

Im getting a GTX 570 tommorrow or the next day too.

Nice choice. I just installed my GTX 470 today and its pretty cool (although I wish I could have gotten a GTX 570 but its not supported on the Nvidia Zalman drivers). Was able to actually play Metro 2033 in 3D at nice speeds (although I did have to set graphics to low, it still looked good). Any other game was no problem. A GTX 570 should be more than enough.

[ghostface]

Im not sure that im getting the right settings...this JPS image is how it looks now - could it look better? Looks kinda weak to me. Does the "stereo separation" in the profiles override the setting that you can change manually in the game? It seems like if I set the "stereo separation" in the driver to something then even if i adjust the seperation with the + or - ingame that it doesnt do much.

Also, how do i make my crosshair work right? Left or right shift?

[cybereality]

On mine I have all these un-checked:
Force V-Sync
Use Simple Stereo Projection
Swap L/R

I am not sure exactly what is wrong, but those images do not look right. The first HL2 image looks like the eyes might be reversed (pseudo-stereo). The second and third don't even look like the driver is working. Usually I set convergence to a low number, like "-0.0005" and separation to a moderate value, like "100". Those settings you posted look within an acceptable range, so I am not sure why they don't work. Make sure to try swapping the eyes and see if that helps. I just tried out the Lost Coast demo, and it looked fine with the default settings (although I did have to swap the eyes). Take a look:

Half-Life 2 #0000.jpg

Settings are:
Convergence = -0.0072
Separation = 140
Auto-focus = Off
Swap L&R

[ghostface]

On mine I have all these un-checked:
Force V-Sync
Use Simple Stereo Projection
Swap L/R

I am not sure exactly what is wrong, but those images do not look right. The first HL2 image looks like the eyes might be reversed (pseudo-stereo). The second and third don't even look like the driver is working. Usually I set convergence to a low number, like "-0.0005" and separation to a moderate value, like "100". Those settings you posted look within an acceptable range, so I am not sure why they don't work. Make sure to try swapping the eyes and see if that helps. I just tried out the Lost Coast demo, and it looked fine with the default settings (although I did have to swap the eyes). Take a look:

Half-Life 2 #0000.jpg

Settings are:
Convergence = -0.0072
Separation = 140
Auto-focus = Off
Swap L&R

is your stereo seperation under the iz3d profile (like in my pic) set to 140 as well? If not, what is it set to?

[cybereality]

is your stereo seperation under the iz3d profile (like in my pic) set to 140 as well? If not, what is it set to?

In the profile it is set to 20 and separation mode: symmetric, clipping width 1%.

[ghostface]

is your stereo seperation under the iz3d profile (like in my pic) set to 140 as well? If not, what is it set to?

In the profile it is set to 20 and separation mode: symmetric, clipping width 1%.

thanks - those settings work a lot better than what I had going. What are you putting for convergence in 3rd person games like GTA 4, mass effect or dead rising 2?

[cybereality]

thanks - those settings work a lot better than what I had going. What are you putting for convergence in 3rd person games like GTA 4, mass effect or dead rising 2?

I usually just set it like that to start, and then adjust by eye. Every game is slightly different. Sometimes it will be necessary to use multiple presets (ie preset 1 for running on foot, preset 2 for vehicles, preset 3 for cutscenes).

[ghostface]

Separation looks OUTSTANDING on a setting of "380"

in the screenshots above I had it on just "80" and couldnt see anything. Well, now that I have set it correctly the difference is incredible.

[cybereality]

Nice to see that worked out for you. I guess everybody's eyes are different. I know I see widely different settings people use.