Ncngrr's Nthusim Questions

[Guest]

I just found the Nthusim website and forum and am really excited about what I'm seeing, especially with this particular setup. I also look forward to seeing the plans and bill of materials.

Here's my situation, I'm putting together (at least in my mind right now) a flight sim in a spare bedroom (10 x 12 foot) of my house. I've initially designed in CAD a space in that room that would support what I think I want (not having seen anything in person). Essentially, it comprises a single-seat cockpit with interchangeable hardware modules that allow me to quickly/easily change between a 1-seater fighter jet cockpit, the left seat of a general aviation aircraft, or the left seat of an airliner. Consequently, the width of the cockpit should be no more than, say, 3.5 - 4 feet at its widest and not much taller than head height when the gamer is seated. I envision a curved screen of approximately 210 degrees (so I capture the peripheral vision) and a 4-foot radius. I believe that works out to about 14' total screen length.

Thoughts/Questions:

1. I've seen short-throw projectors that should work with a 4' radius, but it could be that only works on a flat screen. Can Nthusim and a suitable projector work together on such a small radius screen?

2. How do I go about determining what constitutes a suitable projector?

3. How many projectors would it take? How do I calculate that?

4. How many computer would it take? I understand that using WidevieW would require 1 computer per projector... why would I want to go that route instead of one computer to drive all projectors? Is that even possible?

5. How do I determine what GPU(s) would support this?

6. I've seen where some enthusiasts have used screen materials from Carl's Place. Any comment regarding the viability of that material?

By my questions, I'm sure it's obvious that I'm only just starting down this path and I have a lot to learn. Any suggestions would be greatly appreciated.

Thanks.
Scott

[BHawthorne]

1. There is something called Projector Calculator Pro that you can find via Google. It'll give you a good idea of just how specific projectors will work and lens throw distances. One thing to be mindful of that the shorter the lens throw and the tighter the corner radius on the screen that the more extreme the bow of some of your projection will splash outside the screen area. This is something that only happens with curved screens though, it does not happen with flat panel setups. Curved vs flat panel might be something to keep in mind if you go really tight radius. Nthusim is fine on any radius screen you want to do. The only limiting factor is the behavior of the projector. Is the projector projecting into a surface that has too much varied depth to focus well? Are too much of the pixels splashing outside the usable screen area? While most Nthusim examples show curved screens a lot of people do use it for flat too. It's a matter of personal preference.

2. The room size pretty much dictates what range of projectors to use. In a 10x12 room like you say you plan on using, you're going to need short-throw lens projectors like I typically use. Lens throw ratio between 0.49:1 and 0.72:1. My current projectors are 0.72:1 and my previous ones were 0.62:1. Also I don't like anything less than 2000 lumens and a native resolution of no less than 1280x800 per projector. Things get rather pixely if you don't watch out in your design. Projector Calculator Pro is very helpful in screen design. You immediately have numbers to work from if you knwo what projector model you want to design for.

3. I can do ~200 degrees with just two GT720's. That is my current setup. I'm letting the excess FOV just splash outside of the screen and use for extra edge blending overlap. 4 foot radius is rather tight. For the longest time I always told people never to less than 6 foot radius and three projector. I broke my own rules in 2011 though by going two projector and now in 2013 going down to 5 foot radius. I suppose you could do 4 foot radius, but you'll end up with a projection height of around 48 inches. I'm used to 60" projection height in my builds. there are advantages to 48" though as you get better pixel density PPI. Ultimately you can do it with 2 or 3 projectors. I use 2 because it's just that more cost effective. With the price of everything you end up buying for a simpit cutting out the cost of a third projector pays for a lot -- enough to get a Thrustmaster Warthog and Saitek combat pedals.

4. You can go either way. We jsut this week added in a new feature to Nthusim Standard where you can now edge blend across multiple Nthusim Standard installs now. That would be how you would do it with Wideview. You'd enable wideview and then have a license for Nthusim standard for each PC. Or you can just use a single PC and multiple projectors with Nthusim Plus. Frankly, if FPS rate bothers you, you almost have to go the wideview route though so you can offload the processing power between multiple computers. It pretty much means the difference between 40 fps and 20 fps in FSX/Prepar3d. I'm used to single computer so I just cope with the 20 fps. Regardless FSX/Prepar3d are a headache for FPS rate and are really CPU bound.

5. If you go single computer you'll need a spanning technology to do this -- AMD Eyefinity, Nvidia Surround, Matrox TH2G, Zotac DP-to-Dual-HDMI adaptor, etc... Be mindful that if you do dual projector that Nvidia Surround won't work. You'll need to use the Zotac adapter I mention to enable the span. If you go multi-computer really any card will work. You're just pushing one projector from one video port.

6. It's ok, I've used it before. I'm more apt to just go to Home Depot and wood fabricate a screen with masonite or ply though and use a custom DIY paint like "black widow". Some DIY AV forums have the formula to have that paint mixed at places like Lowes and Home Depot. There is no real right or wrong answer in DIY screen building. Some answers are more right than others though and most people are used to experimenting with their screen design and materials used. It takes a bit of patience and the willingness to tinker because there really aren't plans out there right now for this kind of thing.

Really, most of us are making it up as we go along. I'd like to say I have all the answers but I don't. It's also why I keep on having fun making new screens and experimenting with screen materials and frame layouts. I've yet to find what I consider ideal for me. Yes, they all work, but I tend to like to refine things over time learning from my past builds. That's why the site is seeking to create a community though. That way everyone can share their building experiences and exchange information on what materials work better than others. My ultimate goal is to have a busy and thriving core group of users here that have fun sharing their building progress and finished setups. I think that'll be closer to reality now that we're expanding to HMD VR too with the Oculus Rift. Between the projection setups and HMD setups I think a lot of interesting gaming setups can be documented here in ways that'll help others learn what is possible.