Extrude along path in y direction path with face in XZ plane #148

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1. BAleiHi commented on Jul 13, 2020

   

   BAleiHi

   on Jul 13, 2020

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   Sorry - that was a test after I encountered the original problem. The simplest version of this that did not work is:

   from euclid3 import Point3
   from solid import scad_render_to_file
   from solid.utils import extrude_along_path

   a = extrude_along_path(shape_pts=[Point3(0,0,0),Point3(0,0,2),Point3(2,0,2),Point3(2,0,0)],
   path_pts=[Point3(0,0,0),Point3(0,10,0)], scale_factors=None)
   file_out = scad_render_to_file(a, 'test.scad', include_orig_code=True)

   which produces:
   

   Does extrude have limitations on how the "shape" and "path" are defined?
2. etjones commented on Jul 13, 2020

   

   etjones

   on Jul 13, 2020

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   The simple answer is that shape_pts need to lie in the XY-plane.

   If you change your line to:

   a = extrude_along_path(shape_pts=[Point3(0,0,0),Point3(0,2,0),Point3(2,2,0),Point3(2,0,0)],

   ( transposing the Y & Z dimensions of your original) you end up with a rectangular prism as intended.

   I need to check on this in the documentation. The XY-plane limitation is in the comments at the top of solid.utils.extrude_along_path(), but that doesn't help much if it doesn't make it into the docs, huh? Sorry it's been left out.

   Anyway, for the moment, here's the comment from the extrude_along_path() source specifying limitations:

       # Extrude the convex curve defined by shape_pts along path_pts.
       # -- For predictable results, shape_pts must be planar, convex, and lie
       # in the XY plane centered around the origin.
       #
       # -- len(scale_factors) should equal len(path_pts).  If not present, scale
       #       will be assumed to be 1.0 for each point in path_pts
       # -- Future additions might include corner styles (sharp, flattened, round)
       #       or a twist factor

   As I think about it now, it should be possible to take the normal of shape_pts and make calculations based on that rather than assuming that shape_pts is in XY. I'll add this to the TODO queue
3. etjones

   closed this as completedon Jul 13, 2020