parametric pants

[looo]

This is a project I had in my mind for a long time. Several attempts lead to no result but finally, I was able to do so with the help of assembly3 (placing sketches at points created by a "master-sketch", lattice2 to extract geometry in a parametric way. The creation of patterns and additional modifications (seam-allowances, pockets) are not done in a parametric way. But I am totally happy everything was doable with FreeCAD. And the work with Draft-workbench was a really enjoyable adventure. I was used to a very buggy experience (py3) from the last attempts, but this time there was no crash at all .
The real result is also already wearable, but still has some small issues which will be optimized in the next generation and due to the parametric geometry definition and the intuitive work with the draft module, I am already looking forward to this.

So thanks everyone involved in this project. Keep on doing this great work!

Bildschirmfoto von 2019-11-14 15-06-57.png (67.13 KiB) Viewed 2812 times

[vocx]

LOL.

My first thought was just LOL.

Amazing! Parametric pants.

When I think of parametric clothing the first thing that comes to mind are running shoes, for athletes, footballers, basketballers, and the like.

Is there a huge variation with pants? On first impression I think having parametric dress shirts would be more important. I feel that people tend to vary in arm length, torso size, belly, etc., more than they do with their legs, where basically the waist size is the critical part.

and the intuitive work with the draft module,...

How did you use the Draft Workbench? I feel in the forum the Draft workbench doesn't get a lot of love, because most people are doing product design so they go for Sketcher and PartDesign. I tell people Draft is not a substitute for Sketcher, it's a different concept, more like traditional Autocad drafting.

[looo]

When I think of parametric clothing the first thing that comes to mind are running shoes, for athletes, footballers, basketballers, and the like.

Is there a huge variation with pants? On first impression I think having parametric dress shirts would be more important. I feel that people tend to vary in arm length, torso size, belly, etc., more than they do with their legs, where basically the waist size is the critical part.

Whatever makes sense to you, I don't care much, for me it makes sense.

How did you use the Draft Workbench? I feel in the forum the Draft workbench doesn't get a lot of love, because most people are doing product design so they go for Sketcher and PartDesign. I tell people Draft is not a substitute for Sketcher, it's a different concept, more like traditional Autocad drafting.

Autocad-like tools are still used everywhere. So Draft-workbench is definitely useful.

[triplus]

Nice!

[bernd]

What do you need the mesh for?

[microelly2]

what is your workflow to get the subfaces which are developed to the planar pieces?

[looo]

What do you need the mesh for?

As you cannot unwrap the pants in a direct way (doubled curved sections) there is a need for a "as good as possible" unwrapping which is done with the unwrap tools from mesh-design workbench. It's a very simple FE-method which minimize the total deformation energy introduced by the flattening process (with some assumption of the material behaviour) Similar to other FE-methods a mesh is the basic representation of the geometry upon which the differential-equation is formulated.

what is your workflow to get the subfaces which are developed to the planar pieces?

Workflow is like this:
1. create center bspline. (A 3d-curve would be best, but I used only a sketch)
2. create vertical sections (another sketch)
3. create intersections (points by boolean fragment) *1
4. create sketches of the profiles at the given intersections (by measuring body + adding some amount of extra lengths) *1
5. create assembly and put all part-containers into the assembly
6. align all profiles (2 times point-on-axis for every profile-section)
7. solve and additionally add an angle (if needed, I didn't do this, but afterward realized that the upper back should be longer than the upper front, therefore the uppermost profile-sketch should be rotated a bit)
8. use a simple skript to get part-shapes from an assembly in a parametric way *2
9. create loft of the extracted profiles
10. cut the loft into front and back (boolean-fragments)
11. join all fron and all back faces with lattice2 parametric subelements
-------------- until here everything should be parametric------------
11. go to mesh-design and create mesh with netgen
12. unwrap mesh
13. use the patterns to design the pockets (maybe it's also possible to do this in 3d but I don't think this is absolutely necessary)
14. add seam-allowences (This needs a lot of thinking if you are not used to textil work)

*1 every object used for the assembly is placed inside an part-container.
*2

Code: Select all

import FreeCAD as app
import FreeCADGui as gui

class ProxyAssemblyPart(object):
    def __init__(self, obj, part_container):
        obj.addProperty("App::PropertyLink","part_container","assembly","linked part").part_container = part_container
        obj.Proxy = self

    def execute(self, fp):
        # assume there is only one shape in part!
        fp.Shape = fp.part_container.Shape
        fp.Placement = fp.part_container.Placement

def make_assembly_shapes():
    assembly = gui.Selection.getSelection()[0]
    for part_container in assembly.Group[2].Group:
        assembly_part = app.ActiveDocument.addObject("Part::FeaturePython", "assembly_part")
        ProxyAssemblyPart(assembly_part, part_container)
        assembly_part.ViewObject.Proxy = 0
    app.ActiveDocument.recompute()