Union hangs with junction & reused flatSurface's

[jlvila]

Dear,

Here is a piece of code that produces a TriangulationError (line of code : _p2 = union(_cone, _p1)).
That is specific is that the the _cone is built using 2 two interfaces that I want to reuse to have a closed volume.

from madcad import *
x = 1
y = 1
w = 1
h = 1

_b2 = Box(vec3(0, 0, 0), vec3(
    x+w, y+h, 10))
_br2 = brick(_b2)

color = vec3(1)

_radius = w/2.0
_length = h
interfaces = [
    flatsurface(wire(Circle((vec3(0), vec3(0, 1, 0)), _radius))),
    flatsurface(wire(Circle((vec3(0, _length, 0), vec3(0, -1, 0)), 0.1)))
]

_cone = junction(
    interfaces[0],
    interfaces[1],
    tangents='straight'
)
_cone.mergeclose()
_p1 = union(interfaces[0], interfaces[1])
_p1.mergeclose()
_p2 = union(_cone, _p1)
show([_p2])

[jimy-byerley]

Hi @jlvila

It's true that the boolean operations gets touchy when one of the two surfaces of the operation does intersect the second only on one of its frontiers (like in your case where the interfaces only intersects the cone by their outer ring). That's a common issue with #8

Luckyly in your case (If I correctly understood) you don't need boolean operations with intersection, stiching, etc. You can simply concatenate your cone surface with its ends surfaces using the + operator:

_cone = junction(
    interfaces[0],
    interfaces[1],
    tangents='straight'
)
_cone.mergeclose()

_p2 = _cone + interfaces[0].flip() + interfaces[1].flip()
_p2.mergeclose()

[jlvila]

@jimy-byerley Many thanks again for your work,

[jimy-byerley]

With great pleasure :) I hope it is of some help for you !