Why is Soft Edge applied to top and bottom, not just side?

[gpvillamil]

I am doing a fairly simple mapping project, four projectors across a wall.

I am using Soft Edge to blend the edges (there is a lot of overlap), and am finding that the blend area on the projectors on the end is not just the side edge, but also the bottom.

See the attached screenshots. I would like the edge blend to look like Slice 3, not Slice 1.

Note the excessive shading along the bottom edge.

This looks OK.

[Zoltán]

Could you attach your screen setup preset?

[gpvillamil]

Presets attached

[Zoltán]

Looks like your slice3 is overlapping with both slice1 and 2.

slice overlap.gif (2.24 MiB) Viewed 4086 times

That could be the reason why the soft edge gets confused on slice1, though I don't see the bottom edge when I load your preset.