[simpits-tech] Rendering question

[dabigboy at cox.net]

Hey guys, I'm taking my first steps with multi-projector setups...for now it looks like I will be sticking to one projector, but I am learning all I can about projector setups, optics, rendering, syncing, etc. I ran into a dilemma which is befuddling but makes sense......

My test is with two projectors. I set them side-by-side to see if I could sync up and get a "double width" display. I'm using two computers. In X-Plane (my sim of choice), I've set each computer to a 30* FOV and +/-15* viewing offset. The problem is that the entire horizon rotates as the plane pitches up/down......this makes sense. In normal single-view flying, the horizon of course remains a straight line as you pitch up/down, even though in real life the horizon would be distorted if "condensed" into a single flat display (think of the distortion you get with wide-angle lenses). Since the viewing center of each of my computers is pointing off to the side a bit (by 15*), X-Plane's renderer properly reflects the changing angle of the horizon as the plane pitches up and down. The end result is that the horizon, when viewed with both projectors, makes a "V" or "A" shape with pitch up or down, respectively.

I was just wondering if anyone has run into this before, and how you solved the issue? I *think* (and I'm still having a bit of trouble visualizing and understanding all that is at play here) image warping software like Nthusim or similar would take care of this problem when put in spherical projection mode, but I'm really not sure. I know most people just use a single PC with 2 or 3 displays, and since the sim software's spanned image is just one giant display with the line of sight still centered, the horizon remains straight on all displays. I suppose I can go this route if I have to, but I'd really like to take advantage of the power and flexibility of using multiple display computers.

Matt