Multi-channel / viewgroups / views - cannot align views

[neilhewitt]

Hi.

I'm setting up a multi-channel system with a 180 degree cylindrically curved screen. There are two projectors, one for each 90 degree half of the screen (the screen is too small for a 3-projector system). I have one client machine connected to each projector, and a host machine connected to my controllers and other devices.

I have a blend zone of 12% and I'm using NTHUSIM to warp and blend the display. This has been done properly and is as close to pixel-perfect as I can get it.

After some struggling, I got the multi-channel stuff figured out. After further struggle, I understood the view group system and have defined a view group for my outside views and assigned the views to the correct machines and displays. However, no matter what I do I cannot get the left and right views I have defined to blend properly in the centre. Using the overlap function I can get the two views to the right position on the screen so that they overlap to the right degree to blend, but they will not overlap completely because of the spherical projection P3D is applying to the views. They might overlap perfectly at the centreline of the screen, say, but at the top and bottom they will be significantly off.

I have tried many combinations of FOV, zoom factor and overlap settings. Setting the view group projection to flat is a lot better than cylindrical (presumably because my warped display is basically a flat surface projected to a cylinder by NTHUSIM), but no matter what I do, P3D applies some correction of the view at the edges, and since the middle of the screen is where two view edges meet, things never line up properly. I have to take the zoom up to 5+ to get remotely in the right ballpark, and that's clearly too high.

I know this is possible to do, because I've seen videos of blended multi-projector systems using P3D and they look fine. What am I missing? Is there some secret setting I'm unaware of? It seems like what I need to be able to do is turn off the spherical correction being applied to the view - can that be done with a custom camera?

If anyone who's built a similar multi-projector curved-screen system could spare me a little advice, I'd be very grateful, because I'm tearing my hair out :-(

NH

[NatCrea]

Sounds like you're doing a simple single view blend, but creating a multiple view flight..will never work.
It should look "OK" if you go back to a simple forward view in P3D.

Nat Crea