Filling a hole with a tangent surface

Is there any way to fill this four-sided hole such that the fill surface is tangent on all four sides?

Whatever i try I get one or more edges that are not tangent. Here, a networksrf. MatchSrf does not want to do all four edges for me at once and doing them one at a time just shifts the location of the non-tangent edge.

Problem (488.2 KB)

EdgeSrf to create a surface which fills the hole.
MatchSrf with Preserve isocurve direction on each edge, one at a time.

The surfaces have a very large number of control points.

0.001 degrees is extremely tight for the angle precision. Typically angle tolerance of 0.1 or possibly 0.01 degress is appropriate.

Hm. I don’t think you can have 4 tangent edges on that surface due to the sharp kink upwards in the leftmost corner (in picture).

This is what I could achieve with XNurbs interpolation. Also there are two other edges in your surfaces which are not very good as can be seen with the zebra analysis.

The initial surfaces just won’t allow tangent matching these edges directly. Needs more preparatory work.

Problem Fill RE.3dm (1.4 MB)

I guess this problem could be expanded to how to fill the entire area, including the triangular area. I keep going back to this problem and have not found a good solution to this area.

I use 1/64" as the tolerance. I copied to a blank file with the smaller tolerance.

I have tried bringing the surfaces down to that corner but have never gotten the curves to work out above.

An observation: The initial surfaces are not very dense. With each surface I add and match, the density of the new surfaces grows. This, as the last hole to file is the most dense.

Another density problem is sweep2 generates really bad shapes for this purpose in most of the sections (I have previously posted examples of how Sweep generates really horrible shapes here). I have to resort to the dreaded NetworkSrf for more surfaces than I would like. There are sweeps where possible.

I note that the blueprints do not have measurements for this area. There are measurements forward and aft but non for this. It must have been problematic for the original drafters as well.

The problem could be rephrased as how to fill this hole:

Problem Fill 2.3dm (3.4 MB)

Tangency not needed on the upper edge.

Hm - I think I’d piece it together something like this:

but I do not think you get to keep tangency to the vertical triangle, with that hard corner there.