Rear Projection and a Curved Screen

I have a triple screen set up and tried the Fresnel Lenses option but it is not working out as I had hoped.

Ideally the Frex canopy is the way to go but as it is sooooo expensive it is not an option so I went looking for rear projection material.

My thinking is to I fabricate a curved screen made from rear projection material and mount it in front of the sim projecting from the rear.
The problem I see is the outside image will be distorted probably key stoned to unacceptable proportions and the image will be strong at the center and faint towards the outer edge.
Obviously the latter is depending on the amount of curve I use, if this is a viable idea I need some help in determining the curvature vs. length vs. Height of the screen.

In addition to the above concerns the PJ will need to be a fair distance from the screen to allow for an adequate spread of the image and avoid hot spots also space for me is limited (Take a look at my setup photos)
So I was thinking to angle the screen upward about 15-20 degrees in such a way that the PJ can be mounted above and aim down much like the Frex canopy. I just will not have the elliptical effect that the canopy offers but something similar.

This again raises keystone issues so before I splash out on some screen material any thoughts or suggestions would be greatly appreciated

Hi Brightonuk,

I think you should ask Nima here in the forum, he has the most knowhow regarding screens, projectors, rear projection, etc. !!!

Two questions reg. your sim:

• which graphics card do you use with your 3x 28 Hanns-G - an eyefinity supporting card or a TH2Go ? Do you run 1920x1080 ?
• As far as I know, the rpm meter isn't available anymore - do you know where to get it anyway ? Is it a simple USB-device which runs with appropriate plugins ?

I am using 2 X Nvidia GTX295s in an SLI config and went with the Mviewtech MV103 HDVEPro over the TH2Go.

The resolution is set at 3840 X 1024 for each monitor; this was set in the Mviewtech software and also shows up as the default in the Nvidia panel.
I am also playing with over clocking the video cards and i7 processor (just for fun) with the set up I have I really do not need to.

I do have a mechanical tach that I used with the Frex software... that may still be an option as soon as I figure out how to use in with X-Sim

I am going to be experimenting tonight with the MV103 software to try different resolutions for each screen, as the instrument cluster RPM meter is right on the break (between the screens) in Grid also the images look too detached from each other .

Hopefully I can manipulate the resolution on each screen to offer a better triple image spread.
I will fire up Grid tonight and post the image that have at 3840 X 1024 and then try different settings on each screen.

If the MV103 can display different resolutions to each screen any suggestions to what to start with? As the software has about 30 settings for each screen and I do not want to spend hours trying to find one that may work.

OK Problem solved

http://www.geekologie.com/2006/10/dome_screen_gives_360_degree_v.php

I look forward to seeing some pictures. It's interesting because I own a Hanns-G 28 as well... Would it be possible to make some video footage too ?
A friend of mine is thinking about selling his Hanns-G , so only one screen would be missing yet !

These monitors should display good 16:10 1650x1080, only by using the TH2G digital...
Have you tried it?

Cheers,

MY

Re: OK Problem solved

:rofl:

Erick, when did you install the cameras in my house ?

:rofl:

hi,
the dom is a nice piece but to big for use on a simulator.a rearprojektion are better if you have the right size.i have make a paint were i mean is the best screen design for race.you can use the soft were raceray have say or you projection mast go over a mirror were is a littel banding.or you make only a black mask beside the projection.
or in any years this onehttp://www.golem.de/0801/57135.html

I will try to get some video up tonight if you look at my photos it gives an idea of how the set up looks

I use a Mviewtech MV103 HDVEPro over the TH2Go as I was hoping it would allow me to set different resolutions on each screen to customize my views, but I tried last night and when I set a different resolution on one screen I lost the display completely then spent 30 minuets trying to get it back (as it was the default screen for the pop up Nivida tool box)
I am hoping that is was just my choice of resolution that caused the failure and willl try your suggestion of 1650X1080.
I will also get video or photos of GRID up tonight to show the detachment of each screen.

[*]But a word of warning; I drive like crap so no comment on the quality of my ability to navigate a course.

OK I have come to the conclusion that this looks like a good option as far as imaging goes http://www.vcsims.com/vcsims-racingsimulator.html

I spoke to the manufacturer but they will not sell just a screen, so I would like to attempt to construct one.

As I am using a FREX with a custom cockpit I was hoping to follow the same mounting style that VCSim uses

As a prototype I need a projectable ridged surface that is bendable I was thinking a 5mm thick plastic sheet or even a thin sheet of plywood or a similar type of wood. I can bend it to the correct shape and the fiberglass the back to make a rigid screen then and coat it with this http://www.projectorscreenstore.com/PSS-Projector-Screens-Paint.html

As it will be a forward projected image Nimas sketch is too extreme so what are the optimum angles for a short throw PJ?
Should I go for a gentle bend say 5-10 degrees across the whole screen or have a flat back and bend in the outer edges.
Any ideas?

Re: FRONT Projection and a Curved Screen

The VCSim uses front projection contrary too what the rep told me, the ridged screen is still my main idea but to mould the pattern wood or plastic will not work for me I need something bendable but will hold the bend.

I was thinking of using two thin metal bars to form the basic horizontal curves clamp the board to them fiberglass the board so it holds its shape and cut out where the wheel goes as in the VCSim screen.

(Just thinking out loud but am always open to better ideas)

I also found this software that I belive will solve any warping issues.

http://www.nec-display.com/dl/en/pj_soft/gct4.html

Only 32 bit OS

Agreed. I'm really surprised that their isn't an open source project for this yet.

You can add Immersaview's Sol7 to the list as well: http://immersaview.com/technology/sol7

Some time ago I red in a post somewhere, that one of the immersaview guys had offered a SOL7 non-commercial light version for the flight sim community.
But I cannot find the thread/forum anymore.

guys checkout mycockpit.org they had some info about sol7 light there

Thanks wannabeaflyer
That is a great site and I found some very interestion postes one being this one:

Matt is correct. Sol7 is deigned to remap the image, not to stretch the image. We don't do anything with the field of view (FoV) in the software application, but map the FoV of the image to hit the screen's FoV correctly. This is a confusing subject to describe without pics, so I hope I provide some insight.

There are two different problems when projecting onto a curved screen:
1) distortion correction (taking a planar image and correct it for a curved surface)
2) getting the FoV of the software to match the screen.

We can achieve 1 with Sol7, but 2 has to be done in the software and here is where I understand there to be a limitation in FS settings. For most commercial sims, the software application will give you FoV settings (and generally multiple camera settings for more than one projector/display), so each projector's FoV matches the software's FoV. All of this infomation is really needed to make everything 100% correct. Sol7 can then warp (and edge blend) this info to stitch it all back together correctly so it's visually correct.

Taking the distortion correction issue, Sol7 will remap the image so flat can become curved. When designing a screen, we make sure that the curved surface is the same dimensions as a planar one. So a 130 screen is still the same physical size, just curved towards the user. This is an important factor to note.

And here's where is starts to get interesting again. The radius of curvature of the screen increases the FoV of the display as the edges move closer towards the viewer. Smaller radii will give more immersion (and FoV) but will effect the focal characteristics and the amount of warping.

So here there are other considerations which include:
1) the focal range of the projector (too much curving will cause focus issues)
2) the throw distance of the projector (a large throw distance will cause image shadowing when the viewer sits in the center of the screen).
3) as Sol7 remaps the image, the larger the curvature, the more pixels that are lost.

We have found that it's possible to go from a planar screen (approx 80 deg FoV) to 100 degs FoV when curved. So in my opinion (I have a single projector onto a curved screen sitting next to me as I type) there is quite a considerable benefit from going single flat, to single curved.

The software settings in FS though are something I'm not familiar with. I run 2004 and X (Demo) without changing any visual settings and the info looks visually correct.

I think the real key when testing on a screen, is to take the same screen size as a flat setup and curve it, rather than making a screen with a new aspect ratio as that will certainly cause all sorts of visual problems.

Once we get TH2Go implemented, we'll work on posting some of this information (with pics) on our website to describe this interesting area in more detail.



I think the sol7 may be the answer but again I find myself outta my depth in the Know what they are talking about department.

I did however find the ideal matirial to start my project (Home Depot)