How to control surface with rails and profiles?

Codi · January 8, 2018, 7:42pm

Hello.
I’ve stuck with trying to build “nice” surface along the profiles guided with rails :(

There are two main rails (top and bottom) which are highly fixed (a small deviation is acceptable, not welcome but still can be )
Earlier I tried sweep with 2 rails - failed.
Next tried to segment the fuseladge and build surfaces with loft - failed.
Next I tried segmented surfaces based on 4 edge curves - was better but failed with how to blend segments with control (I thought it is possible like in a “Adjust Curve Blend” then would be excelent).

So far the best results I got with “Surface From Network Curves”.
As two rails are fixed - there was no control to me how to control transition between segments.
In my dream I wish to place a line “sticked” to the profiles and via Curve Control Points to control shape. So far any changes on third line brakes connection with profiles.
As a result “Surface From Network Curves” is averaging somehow distance between profile and third rail.

Could anybody advice how to design surface on a given fuselage with more control between segments (having in mind 2 rails are almost fixed)?
How to change “on the fly” second profile to see how the surface is changing?
How to “stick” third rail to profile in order to pull the control line and simultanously “deform” in one direction sticked profile?

Any advices are warmly welcome (already spent many, many hours) and stucked …

Thank you,
Codi
Rails_profiles_surface.3dm (617.4 KB)

pascal · January 8, 2018, 9:12pm

Hi Codi - the way you have the curves arranged, I’d be inclined to make it in sections.

Make all the cross section curves have the same structure - one way to do this is to Rebuild to the same degree and point count - I used degree 5 and seven points, it might be possible with six points.
Make the pairs of rails match
Make EdgeSrf surfaces and then MatchSrf for tangency between sections.

My rebuilt curves with some quick edits to match yours are blue in the attached.

Rails_profiles_surface_PG.3dm (133.9 KB)

@Codi - it looks like I used one of the more complex curves rather than my simpler ones in making one of the surfaces in my file - I fixed that and updated the file - now, if you turn on all the points there is a consistent structure all the way along.

-Pascal

Codi · January 9, 2018, 6:46pm

Hello Pascal.
Thank you for your suggestions - I think I got the point with equalise points and degree curves
Also I read more about basics “know how” from recommended lectures:

“Degree of Curves: Is there any good tutorials?”

I workout with surfaces and would like to ask if there is a way not only to Match Surfaces but more blend it where there is control over “the blending distance” (aka Adjust Curve Blend).

By now there is a “kink” which I would like to diffuse/blend but … I don’t know how

Thank you for support,
Codi.