Existing workflow
- Import/define body measures of the person who is going to wear the clothing: This could be done as properties of a scripted object. Due to technical problems I used a separate sketch for this which is a perfect solution for me.
- Sketch the outlines of one piece of the pattern in Sketcher
- Make sketch dependend on external measures
- Use more or less complex formulas and constraints to adjust the outline of the piece
- Use symmetry constraints, because many parts are left-right symmetric
- Create a TechDraw document and add the drawing of the piece to a page
- Export document as SVG or directly as PDF for large format printing service
Missing features
There are a few essential things missing. As far as I see they could be implemented by scripting or are allready under construction. What is missing?
- Adding seam allowance: For many simple use cases it is sufficient to create a 2D offset around each part we have drawn in sketcher. In more complex cases some curves or lines may or may not need a seam allowance. I could be necessary to select elements that need a seam allowance. Possible ways of realization:
- 2D Offset tool in sketcher: This is allready in work.
- A kind of postprocessing feature between Sketcher and TechDraw. This is the way the seam allowance is realized Seamly2D.
- Matching parts: Normal clothes consist of several parts. Typically connecting edges of two parts are restricted to have the same length. There are exceptions like quillings, but the normal case is a clear match. A typical case where three parts have to match a common curve length is a sleeves seam to the two body parts (front and back). While the top end of the sleeve has a gaussian like shape, the cutouts in the front and back part are more or less simple curves. The condition we have to meet for a functions sewing pattern is that the curve length of the sleeve is equal to the total length of the two cut out curves on front and back part. I know that it no point and click automatic to realize this matching without user interaction but we will need a few things to make it possible:
- Measuring curve length between a start and end point in a sketch or curve length of one geometrical element.
- Adjusting one or more points in one or more parts along a predefined vector to match the curve length to a mathematically defined condition. Adjusting curvature could also be an option, but adjusting points is more straight forward and more effective.
Your opinion
What is your opinnion, what are your suggestions? I am really interested in discussion this topic with you, because I think this could become a really nice and new application for FreeCAD. I think about extending this idea to a full grown workbench including 3D simulation of clothes as realized in Marvelous Designer and other professional 3D tools. The FEM tools are allready there :-)