How do I fix jagged edges in 3D?

I'm using trilinear sampling and it seems to smooth curves and oblique lines, but only in an in-object fashion, and not inter-objects (i.e. not between adjacent objects on screen). That is: observe in the image how the lines circled in blue are completely smooth, but the ones in red circles are not. I suppose it is because pixels that come from the same objects are anti-aliased with each other, but pixels at the intersection between two different objects are not. (Sorry if I'm not using the correct terminology, I'm not a specialist.)

Does someone know how to remove the jagged appearance from the parts circled in red?

The sampling method affects how the textures are blended. Hence the nice anti-aliased lines on the textures on the 3d shape. The 3d shape itself is drawn with triangles and the edges come out aliased like that. I don't think there's a solution within construct other than a layer effect to blur it or something.