Image applied as a UV texture is deformed I am trying to apply an image with a horizon line of a city on a plane.



The face I'm trying to apply it to is like a trapezoid shape.



But when I preview the render in rendered view, the horizon line seems skewed (bottom right preview):



If I change the size of the two vertices on the left in UV image viewer, I get a rendered preview that makes me feel like the plane isn't really plane, and that Blender is adding an invisible edge to deal with this:



I've found this question here "How to flatten a face to avoid distortion (make an ngon planar)", but none of the solutions on this question helped solve it.

Blend:

 

Note: this model is inspired from the works of Patrick Hughes.
I think that for what you are trying to do you need to set the right ortho view and unwrap using project from view (bounds):



Then set your material to actually use that newly created UV map as coordinates:





If you still have some deformation, use a subsurf modifier, but instead of the default Catmul-Clark subdivision use Simple