Coding for non-uniform/trapezoid landscapes

Introduction:
I am trying to create a game that has the landscape laid out as an inverted sphere. Think of Inception. The idea for the sphere is a box smoothed over several times within Maya. This gives a reference in how the landscape would be laid out. To be able to properly fit the landscapes together, the landscape must be non-squared/trapezoid in shape. There would be some deformation of the height map if and when applied, but that is livable.

What I have tried:
I have tried to lay out the landscape by hand, but the edges never match up and there are gaps. I have gone as small as 256 x 256 to see if it would at least line up most of the time, but still same issue.

What I want to do: - This will likely need a DEV answer and help if possible.
I want to be able to modify via. code the landscapes that I create and assign them trapezoid shapes. Is there a direction that I can be guided too? There is hardly any documentation within the code to help with the uninitiated.

I would hate to have to drop the game idea because I think it would be an awesome idea.

Thanks.

do you need to use a landscape? I would think it be easier to model the inverted sphere landscape in maya then import it into ue4 as a static mesh.

Also just a thought,
You’d have to throw a quick prototype together to see if this will work, but you could, in theory, use a normal flat landscape then put a camera directly over the player. The camera would then feed a render target material placed on a sphere that encircles the player.

I have actually tried something like that in the beginning, but it either doesn’t work like I wanted it to or I didn’t really have it setup very well. It would be a nice cheat to do. There will be some flying involved and not sure how that would work with the setup.

you responded as an answer rather than a comment. people might not bother to click your post if they see somebody already gave an answer.

I was a bit curious so I googled around for myself. Wouldn’t be surprise if you’ve found similar stuff, but I’ll share the links.
here’s a unity shader trick that curves the world based on the distance from camera.

If you’re world is really big this could work. Maybe you could teleport/rotate the player around a bit to make it seem like he is sphere. for example, if he flies straight up you could discretely flip him around and swap out the landscape under him.

and here’s a dev talk about building a procedural sphere for a planet.