added export check to splinepy/io/iges.py

[mkofler96]

Overview

iges export now checks parametric dimension of spline, if it is 3, then a value error is raised and a suggestion for a solution is presented

Addressed issues

• solved issue #272

Showcase

calling the example from the issue now gives the following error:

ValueError                                Traceback (most recent call last)
[c:\Users\mkofler\miniconda3\envs\splinepy_dev\Lib\site-packages\splinepy\microstructure_fix.ipynb](file:///C:/Users/mkofler/miniconda3/envs/splinepy_dev/Lib/site-packages/splinepy/microstructure_fix.ipynb) Cell 3 line 1
     [13](vscode-notebook-cell:/c%3A/Users/mkofler/miniconda3/envs/splinepy_dev/Lib/site-packages/splinepy/microstructure_fix.ipynb#W0sZmlsZQ%3D%3D?line=12) microstructure.microtile = getattr(sp.microstructure.tiles, "NutTile3D")().create_tile()[0]
     [14](vscode-notebook-cell:/c%3A/Users/mkofler/miniconda3/envs/splinepy_dev/Lib/site-packages/splinepy/microstructure_fix.ipynb#W0sZmlsZQ%3D%3D?line=13) microstructure.tiling = [8, 4, 1]
---> [16](vscode-notebook-cell:/c%3A/Users/mkofler/miniconda3/envs/splinepy_dev/Lib/site-packages/splinepy/microstructure_fix.ipynb#W0sZmlsZQ%3D%3D?line=15) sp.io.iges.export("test.igs",microstructure.create().patches)
     [17](vscode-notebook-cell:/c%3A/Users/mkofler/miniconda3/envs/splinepy_dev/Lib/site-packages/splinepy/microstructure_fix.ipynb#W0sZmlsZQ%3D%3D?line=16) ig = sp.io.iges.load("test.igs")
     [18](vscode-notebook-cell:/c%3A/Users/mkofler/miniconda3/envs/splinepy_dev/Lib/site-packages/splinepy/microstructure_fix.ipynb#W0sZmlsZQ%3D%3D?line=17) ig.show(control_points=False)

File [c:\Users\mkofler\miniconda3\envs\splinepy_dev\Lib\site-packages\splinepy\io\iges.py:41](file:///C:/Users/mkofler/miniconda3/envs/splinepy_dev/Lib/site-packages/splinepy/io/iges.py:41), in export(fname, splines)
     39 for ispl, spline in enumerate(splines):
     40   if spline.para_dim == 3:
---> 41       raise ValueError(f"Volumetric {type(spline)} found at splines[{ispl}], which cannot be handled by the Iges file format \n"
     42                        "Use a boundary representation instead by calling e.g. spline.boundary_multipatch()")
     44 return splinepy_core.export_iges(fname, splines)

ValueError: Volumetric <class 'splinepy.bezier.Bezier'> found at splines[0], which cannot be handled by the Iges file format 
Use a boundary representation instead by calling e.g. spline.boundary_multipatch()

Checklists

• [ ] Documentations are up-to-date.
• [ ] Added example(s)
• [ ] Added test(s), is this necessary?

[mkofler96]

Thanks! Can you add a round-trip test? You can create a separate PR and we can merge both when the test is ready

Did you think of something like this? tests/test_json.py

If yes: should we keep all import/export tests in a single file? Then one could loop over every import/export method, something like

        with tempfile.TemporaryDirectory() as tmpd:
            tmpf = c.to_tmpf(tmpd)

            export_formats = [(c.splinepy.io.json, {"bas64encoding": False}), (c.splinepy.io.iges, {}), (c.splinepy.io.irit, {}) ...]

            for (ef, ef_arguments) in export_formats: 
                ef.export(
                    tmpf, list_of_splines, **ef_arguments
                )
                list_of_splines_loaded = ef.load(tmpf)
                self.assertTrue(
                    all(
                        c.are_splines_equal(a, b)
                        for a, b in zip(list_of_splines, list_of_splines_loaded)
                    )
                )

What do you think?

[j042]

Thanks! Can you add a round-trip test? You can create a separate PR and we can merge both when the test is ready

Did you think of something like this? tests/test_json.py

If yes: should we keep all import/export tests in a single file? Then one could loop over every import/export method, something like

        with tempfile.TemporaryDirectory() as tmpd:
            tmpf = c.to_tmpf(tmpd)

            export_formats = [(c.splinepy.io.json, {"bas64encoding": False}), (c.splinepy.io.iges, {}), (c.splinepy.io.irit, {}) ...]

            for (ef, ef_arguments) in export_formats: 
                ef.export(
                    tmpf, list_of_splines, **ef_arguments
                )
                list_of_splines_loaded = ef.load(tmpf)
                self.assertTrue(
                    all(
                        c.are_splines_equal(a, b)
                        for a, b in zip(list_of_splines, list_of_splines_loaded)
                    )
                )

What do you think?

yes

[jzwar]

Is this still beeing worked on?

[mkofler96]

Is this still beeing worked on?

yes, I'm still working on the round-trip tests, I just have not found the time for it yet

[j042]

so turns out BSplineLib will append zeros in case of dim < para_dim and always export 3D splines (maybe this is IGES rule?)