A little help with a multi projector setup please.

[Guest]

G'day, Sorry in advance for such a long post , I have been trawling through endless info on the net for a very long time but it is so spread out and fragmented in both location and time, that it is really hard to find a starting point that is going to suit me. I've been a long long time reader of this forum and have been slowly collecting parts to start a build of my own. I started a thread over at WSGF but I've been having an even harder time deciding what I actually want to achieve since I posted there.

What I wanted to do here was re post my original thread and then add my new train of thought, but I can't seem to upload more then one file at a time so I'll just start fresh. For anyone wanting to see my original designs and ideas, they are very easy to find over at WSGF (can post a link if it is ok with the mods?). In a nutshell, I was going to use 3 gt 720's or 750's on a massive curved screen with Nthusim and 3D vision surround.

I have since decided that I don't really want such an extreme curve on the screen as at the end of the day it is mostly going to be used for movies, with gaming coming second (not super high end new games, happy with slightly older titles). This now reduces the need for three projectors and now I can just go with two. Obviously 3D Vision Surround operates on 3 monitors and so I now need to go back to the drawing board and start all over again.

I'm going to destroy my kitchen to make my lounge big enough to do this and I'm moving the entrance of my house as well. I'm planning on making this a very professional install so I'll be sure to take lots of pictures and share my experience with others as I progress.


If I can I'd like to break this thread up into 4 parts. #1 the overall idea, #2 the screen and projectors, #3 the computer hardware, #4 glasses, transmitters, software and general options.


#1 To achieve a duel projector setup allowing for 3D viewing during movie playback and occasional gaming.


#2: Screen / Projectors - Limiting factors, screen height of 1.6 meters (may yet stretch to 1.7 meters), room width of 6 meters, no real throw distance restriction except for screen radius.

I know there is HEAPS of discussion on which projectors are appropriate for curved multi setups and the obvious choices are the 720's or 750's. I agree 100%, especially in a setup with a tight curve, limited space and a large FOV. However, my setup is in the largest room in my house and can take up as much room as needed, so I am looking at alternate options. I am planning on a FOV of only 54 degrees (I feel it will be better for movies? Let me know if I'm wrong), the radius of the screen is 5.5 meters (18 feet), giving an overall screen length of around 5.18 meters (17 feet). Looking at an Optoma HD33, to acquire a vertical screen height of 1.6 meters (5.2 feet) (my limit), the throw distance would be 4.7 meters (15.4 feet).

I've done a quick drawing and it looks as though it should work using those projectors (I may need to play with the final screen radius and projector overlap but the projection distance seems ok at these measurements). Can someone have a quick look to confirm? I have tried to show that the projectors do fit within the radius of the screen with only a 10.6% overlap (I'm aware this is a little low, I will increase the overlap and adjust the screen dimensions to suit if this is going to work). The obvious advantage of this setup is the possibility of longer throw (1080p) projectors.

Setup 4.jpg (155 KiB) Viewed 12520 times

If I can use the longer throw projectors due to my setup, should I be looking at something other then Optoma and the HD33?


#3 Computer hardware. I know NVidia isn't going to work with dual screen 3D gaming on its own so, what are my options?

I have a 52" LCD TV (non 3D) that I watch all of my non-epic content on. I'd like to build a low power consumption, quiet HTPC that doubles as a NAS for everyday (24 hr) use. If it's possible to get the HTPC to run the dual projectors for 3D movies (no games) as well as run the TV and still keep it relatively low on the power consumption side then that is what is what I will do for now. I'm not asking anyone to design me a system, but I would like to know what the minimum GPU requirements and recommendations would be for that particular scenario.

I do plan on building two PC systems in the end, one high end (noisy system I call it) for gaming and one low power consumption (quiet system) for media and storage. I'd just like to start with one machine for now to get it working and experiment with. I'd prefer the first system to be the media pc as that is the primary use of the screen. I will probably end up purchasing a second copy of nthusim anyway as I dare say this won't be my only widescreen build so having an all in one is not really my final goal right now.

As far as games go, I was totally sold on 3D vision surround, I even have the GPU's ready to go, but it now looks like I need to go a different route due to dual screens. I've never played a 3D game before so I'm not totally sure that it will be something I will actually want to do or not. I may be totally happy with just having a massive high quality screen but I want to try 3D on a few different platforms to get a feel for it first. At the moment it's mostly titles like Oblivion, Fallout 3 and Skyrim, I may try out a few FPS's as well and then I want to try my hand at flight sims. I may not like playing on such a huge scale but if I decide that surround gaming (in 2D or 3D) is what I really want, then I will use this screen build for FPS style games and I'll build another system in the man cave using 3 projectors in more of a simpit style for flight sims, racing and general immersion.

To summarise, what I really want to be able to do for now is watch 3D movies and just try out a few different games on the dual projectors (at low settings) and then go from there.


#4 Glasses, emitters, software, compatibility etc.

I thought I had it all worked out with the 3D vision surround, but now as that has changed and my deadline for having a design finalised is getting closer, I need to be totally schooled on what I can do.

I know it's all going to come down to the final choice of projectors (2 or 3, brand, etc) final choice of hardware (NVidia or ATI), if I'll be using something like a matrox box to extend a single display across the projectors (not sure if they make one that will handle 2 x 1920 x 1080 @ 120hz) but regardless of what I end up with, I want the best possible overall experience so I thought I'd add this section to wrap it all up. If anyone can make suggestions in this area (how would you do it? what are your current experiences?) then please feel free to chime in as I need a little point in the right direction before I spend even more money.

It's all a bit overwhelming once you enter this realm and I don't know if I have enough knowledge or time to learn it all myself from scratch again, so thanks for any and all help.

Cheers.

[BHawthorne]

I've always been of the mindset that unless you do at least 120 degrees a curved screen is largely meaningless because a curved screen's prime goal is to give a sense of depth and peripheral view. Under 120 degrees there isn't enough depth to the screen design to accomplish that. Might as well go wide flat screen at less than 120 degrees. If movies are your thing go for between 2.37:1 and 2.66:1 aspect ratio. Blu-Rays are ideal in cinematic 21:9 (2.37:1) AR. I won't discourage you from doing a curved screen but I'm giving my reasoning why it's more trouble than it's worth at less than 120 degrees. There is no real need to actually curve the screen when pre-warping. A lot of people still pre-warp flat screens too and primarily take advantage of the edge blending capability.

I am a fan of the new BenQ W1080ST projectors if you have budget. If I had money to do so on my personal setup, I'd buy those. If budget is issue I really like the GT750e. It's a bright and sharp projection for the price point.

About Nvidia and dual-projector spanning. You need to purchase a Zotac DP to Dual-HDMI active adapter. That'll handle your spanning issue. Newegg carries the adapter. Not 100% sure if the adapter has enough bandwidth to do two 1280x800 @ 120hz. If you need that though MView has a box that is capable of it though that is similar to a Matrox DH2G but has bandwidth for 2560x800 @ 120hz.

Sounds like a pretty dramatic remodeling plan. Should prove interesting for you to document the build. Be mindful that ambient light is the enemy of all projection builds. You need to have firm control over the room light levels in the room the projection is in.

#1: Answered above.

#2: Although you're doing this in a large room you still are hostage to whatever projector lens throw you end up using. Be mindful that unless you have really tall ceilings the longer the lens throw that more possibility you have that you'll be walking through your projection all the time in the room. Use Projector Calculator Pro to work up the math and mounting locations. My thoughts on curved screens are mentioned above.

#3 Nvidia and 3D Vision options are mentioned above. An HTPC should be ok for media content. Depending upon the GPU it'll play games fine too. I suggest a GTX660 minimum even for the HTPC. I never like to skimp on GPU. The thing to keep in mind is if it can push 2560x800 at a decent FPS you're in good shape. 2560x800 is pretty comparable to the pixel count of 1080p.

#4: I've been using NVIDIA's proprietary first generation 3D Vision wireless kit with glasses and emitor. They work fine on my setup with the MView box and GTX460.

[Guest]

Sorry for the late reply and thank you for all the info Brad.

I've started my renovation, already destroyed one bedroom and now getting ready to move the kitchen.

I understand what you are saying about the depth appropriate to the amount of curve and thanks for pointing out the BenQ projector. Regarding the aspect ratio, I didn't think it would be that important to reduce the physical projection width, I was just going to keep it as wide as possible. If you were watching media with a different AR wouldn't the computer just "frame" the content with appropriate width black columns? I have considered building some rails into the ceiling so that I can draw black curtains over the screen to keep it free of dust and also reduce glare from any unwanted overshoot.

If I could dual span the BenQ's at full resolution with a splitter / box then I'd go for them straight away. I think for now though I'll purchase 3 GT750e's to play around with, I can use them to experiment with flat and curved screens, 2 or 3 projector combinations and 2D / 3D content. I'll probably upgrade to the BenQ's later on and then use the GT's in another rig. I already have a test PC with 2 X liquid cooled GTX 295's that I can use to get it all setup properly so just need the projectors and glasses / emitter. I'll build a better PC once I'm happy with the projectors. Hopefully Nvidia will come to the party one day with dual screen 3D gaming.

It's probably going to be quite a long time before I have any real updates here because I have a lot of work to do on the house before I'm ready to set these up.

[BHawthorne]

Yep, it'll just pillarbox it depending upon the player. I really am a proponent of AnyDVD and Media Player Classic Home Cinema to manually play back Blu-ray content. I really like the 10-key built in scaler control MPC has. You can easily output the movie content at any aspect ratio you need with the controls it has. One thing to be mindful of is that 2.37:1 and 21:9 aspect ratio cinematic Blu-ray content is 1920x800, so even running two 1280x800 spanned will get you pretty close to native for Blu-ray.

I'm not 100% sure but I believe the Zotac adapter is single-link so that'll hamper your ability to push 2x 1080p @ 120hz. I'd like to say the MView box could push 2x 1080p @ 120 but I don't think it can. Dual-Link DVI that the MView box uses simply doesn't have the bandwidth needed to pull it off at 3840x1080 @ 120. That would have to be something MView would have to answer to be 100% sure on. I have the box myself, but I've only ran it on 2x 1280x800 projectors at @ 120. Frankly I'm interested in finding a solution to the 120 hz issue because the BenQ W1080ST looks like a great projector. The GT750e will work good for your needs though. I've seen several examples of new builds using multiple GT750e on the Eagle Dyanmics and the WSGF forums and everyone says they're comparable to my GT720's.

I really hope Nvidia gets with the program with 2x1 spanning capability in the future. It's an oversight on thier part to not understand that people often piecemeal add hardware to their systems 1 -> 2 -> 3 displays. To skip over dual display spanning was really short sighted of them in 2010 and is even more surprising that they still have even with the new 600-series port options they accommodated.

No worries on updates, just let us know how things are going when you have something new to share.

[Guest]

Still working on the house, I have to brick in an entrance way and a few other things before I can start on the cabinet for the screen.

If I stick with the plan of purchasing 3 projectors and only end up using 2, I'm hoping that I'll be able to build something similar to the A.C.E.S surround flight sim setup. Anyone had luck with that kind of projection other then those guys? I'm taking a guess that the hardest part would be finding games that can output that type of FOV...

I've had a bit of a look around and wouldn't mind trying my hand at DCS and FSX but have no idea if they will work on something like that. Some racing sims would be sweet as well. I wouldn't mind if there were only a couple of things I could run on that type of screen as I'd have the big one for other games and movies. If I'm still hung up on a large FOV screen when I upgrade the 750's I can always build another smaller surround screen with a 120 or 180 degree FOV.

Thoughts? Anyone know of a list of titles that can output that type of view? They only use a single projector in their setup if that's of any help to anyone.

Cheers.

[BHawthorne]

Is the ACES one the Mall sim place that has the DIY domes? The best research material for those is to read up on Paul Bourke's security mirror prototypes. I believe ACES is doing something along those lines. Be mindful that if you do a dome like that they don't show you in a promotional video is the pixel size. Be mindful of the square footage they're spanning the pixels across in something like that. My suggestion would be to use 1080p for something like that. Even then it's going to get pixely. One projector is still one projector's pixel count. I think it would still be cool, but go into it with the expectation that it might be blocky. I really dread projecting taller than 60" because it bothers me on the pixel size.

[Guest]

G'day, sorry for the massive late reply.

I'm still working on the house, a one room reno became an entire house, yard, workshop and carport rebuild. There is now even talk of building a new house on a new property so curved projector screens have to wait.

About the only thing I can share is that the lounge / cinema room is going to remain a flat screen with a maximum of two projectors, I may even just go for a single due to ease of setup. I do however have full permission for a full on man-cave once the house is finished so will most likely be lurking around here again when that happens.

I read somewhere that you were going with a full dome rear projection setup Brad? How has that gone?

[BHawthorne]

Late last year I commissioned a factory in China to build me a prototype but the metric-imperial measurements somehow were wrong and I got a dome too big to use. I've been talking this week with another Nthusim user and he's doing his own full dome experiment. I'm still looking at doing one but it being front projection instead of rear projection now. Something along the lines of Microsoft Research's WorldWide Telescope Planetarium design but the screen being a 12-gore dome. That way I have easy to line up seams for calibration on the dome for 2, 3 and 4 projector setup. My thought is I want to do an Omnimax style design with a 30-degree tilt to the visuals.

Here is a pic of the dome I had made last year. I superimposed a cubemap grid on it to visualize how I would calibrate it.