An example of Gordon Surface based upon OCC

[microelly2]

bp_828.png (48.61 KiB) Viewed 2320 times

one profile has the false direction but it works fine.

red is the result
green is S1
brown is S2
and blue is S3

I made this video with my example to see the differences of these helper shapes

phpBB [video]

the short but good article about gordon surfaces is here:
http://old.cescg.org/CESCG99/MKuklisova/node1.html

[freecad-heini-1]

Whow Thomas, very nice. Please can you try to create a gordon surface with m experiments to design the tide-bottle in Freecad:

tide_bottle_gordon.fcstd

(115.19 KiB) Downloaded 111 times

[hammax]

… after installing last CurvesWB-update (7) and turning my stern-profile by placement z=180° it works.
But: I had constructed my hull frames by copying from a single starting frame and modification, there should be no fish-twist.
All original placement data were ok.
Maybe the new grid sorting algorithm wants it in this special form.

Gordon_6.PNG (76.82 KiB) Viewed 2272 times

[microelly2]

Whow Thomas, very nice. Please can you try to create a gordon surface with m experiments to design the tide-bottle in Freecad:
tide_bottle_gordon.fcstd

I had to model the circle and the ellipse as beziers,
here are the sketches and curves

bp_829.png (6.9 KiB) Viewed 2260 times

and here the surface

bp_830.png (22.86 KiB) Viewed 2260 times

[freecad-heini-1]

Whow Thomas, very nice. Please can you try to create a gordon surface with m experiments to design the tide-bottle in Freecad:
tide_bottle_gordon.fcstd

I had to model the circle and the ellipse as beziers,
here are the sketches and curves
bp_829.png
and here the surface
bp_830.png

Hi Thomas,
what about the tool from the curves-wb to join the selected Edges into Bspline curves?
Are this kind of bspline curves usable with your gordon surface tool?
Best regards
Wilfried

[microelly2]

Hi Thomas,
what about the tool from the curves-wb to join the selected Edges into Bspline curves?
Are this kind of bspline curves usable with your gordon surface tool?
Best regards
Wilfried

it is really not a big deal
and I have already the methods to convert most of the surfaces to bspline surfaces,
and now its the time to do it with curves too.
I allways use at a last step to convet the bsplines to multiplicity 3 knots, that means to bezier objects which are easier to edit
and all my methods in the editor work on this base.
So I see no compatibility problem in future. Any curve and surface should have a way to become a bspline if it is needed to perfom free forming actions.
The idea of the Gordon surfaces I had in background for the way to reconstruct shoes from scan: slice the point cloud, convert the slices to beziers with same structure, create a gordon surface from the slice grid. The big benefit of the gorden is the S3 term which gives better results than the loft and the sweeps with one or 2 sweep pathes.
https://youtu.be/4-S1P9MAA04

[freecad-heini-1]

Thank you Thomas for your answer.

Industrial designer mostly provide 2d drawings with dimensions and views in three or more view.
So the common way is to sketch the curves with this dimensions and not freehand.
To design freeform surfaces, the common way is to create the curves in the sketcher using lines and arcs and bspline curves. In some cases it make sense to convert lines and arcs with the curves-wb tool "join the selected Edges into Bspline curves to a joinCurve feature".
With the option corner-break false you can reduce knots and inbetween faces to reach a nice face. All this steps are full parametric. That means, if I change the sketch, the joinCurve will update automatically and the face as well.

What about your workflow. Is it full parametric? Is it possible to use sketcher bsplines and joinCurve and Lattice2 sublink edges?

Best regards
Wilfried

[hammax]

Hi Chris,
after your todays fixing of the "closed surface bug"
the Gordon feature doesn't work any more.
(Neither in TIGL-test nor on my hull-test.)
FC.18.14061 on Win10-32

[Chris_G]

Hi,
I had to add a dependency to python-numpy.
Isn't it bundled in your version of FC ?
What is the result of this command in the python console :

Code: Select all

import numpy

EDIT : I also forgot to remove an unused dependency to scipy.
What is the result of :

Code: Select all

import scipy

If you get an error here, please try to update CurvesWB.

[hammax]

… numpy is in my package
but scipy is missing (with that I had already earlier version problems) - this should be a task of the FC18dev-package.

In the TIGL-file the following items don't work with the newest update
Full_Nacelle
Fuselage
Heli_Body
Spiral_Wing