Processing weird 2-vertex shapes in P3D and maybe related shapely conversion issue

[villares]

In Processing, if you use the vertex function on the P3D renderer, sometimes 2-vertex shapes ares not drawn.
This behavior seems kind of weird. I think I have seen something similar with lines if called with just xa, ya, xb, yb instead of xa, ya, za, xb, yb, zb, but I couldn't reproduce.

Now, on py5, this seems to affect the py5.convert_shape() feature on shapely.LineString objects, but I haven't looked in detail the source to confirm. I'd like to have a workaround or a "fix" :(
Could we think of something? Should we ask Processing upstream to change this behavior?

Using begin_shape(LINES) seems to help a bit, but again, it's a not solution for the shapely conversions.
Lately it affected my "hatches" experiments, when trying to do them in 3D.

[hx2A]

Yes, this has to do with P3D's triangulation. I would expect to see the same behavior for P2D also because it is really a watered down P3D renderer.

I agree that this should be fixed in convert_shape(). It would have to special case this and draw a line instead of a polygon there. Can you open an issue for this?