VR cave development issue: need to skew viewports to compensate for projector angles

My team is updating a portable VR cave to work with Unreal Engine (currently works with Unity). Because the cave is very small, all of the projectors are at pretty extreme angles. We’ve used nDisplay to split a single window into multiple viewports, but we need to skew each of the viewports to compensate for the projector angles. I know we can skew the perspective of each viewport by modifying the rotation values for the screens and scene components separately in the nDisplay config, but the viewports are still square, which means they won’t align properly with the projection screens.

For Unity, we have a tool that will allow us to generate normalized device coordinates (NDC) for each viewport based on the position/angle of each projector. We could then import these into Unity to skew each viewport as needed so that it would display correctly on the screen. I know that Unreal uses NDC values in screen space - does anyone have an idea how we might manipulate those values to skew the viewports?

i think what you want is “warping” the image , wich should be posible based on what this link says:

i would first try that,
and if not then an external tool for mapping each projector(there are a lot).

personally i created my own tool because ndisplay didnt existed yet when i created my mapping,
i didnt have to deal with curved surfaces but had irregular shaped ones so
my solution was to create a special material for blending and warping and used a multiplayer
system to sync 3 computers to show the same level in the massive display

You could try using Output remap feature of nDisplay to rotate your final output.
giving a shot to easyblend from scalable might work too!