Module openscad_py.path_tube
Classes
class PathTube (points: List[list | Point],
radius: float | list,
fn: int,
make_torus: bool = False,
convexity: int = 10)-
Creates a tube-like or toroid polyhedron from a path (list of points).
Arguments
- points: The list of points
- radius: A float or a list of floats for each point
- fn: int, The number of sides
- make_torus: bool, Whether to make a torus instead of a pipe with ends. Warning: the last segment may be twisted.
- convexity: see openscad
Expand source code
class PathTube(Object): """Creates a tube-like or toroid polyhedron from a path (list of points).""" def __init__(self, points: List[TUnion[list, Point]], radius: TUnion[float, list], fn: int, make_torus: bool = False, convexity: int = 10): """ Arguments: - points: The list of points - radius: A float or a list of floats for each point - fn: int, The number of sides - make_torus: bool, Whether to make a torus instead of a pipe with ends. Warning: the last segment may be twisted. - convexity: see openscad """ self.points = [Point.c(p) for p in points] self.radii = radius if isinstance(radius, list) else [radius for p in points] self.fn = fn self.make_torus = make_torus self.convexity = convexity def process(self, debug: bool = False) -> Polyhedron: """Generate a Polyhedron object from the parameters""" points_rows = [] for ix, point in enumerate(self.points): if debug: print(f"//LOOP {ix}: {point.render()}") if (not self.make_torus) and ix == 0: # Start of the path v = self.points[1].sub(point) # vector toward the first point z_point = Point([0,0,1]) seam = v.cross(z_point) # Track a seam along the pipe using this vector pointing from the middle line if seam.length() == 0: # v is in the z direction seam = Point([1,0,0]) seam = seam.norm() seam2 = v.cross(seam).norm() if debug: print(f"//Start. v={v.render()} seam={seam.render()} seam2={seam2.render()}") points = [] for i in range(self.fn): a = math.pi*2*i/self.fn points.append((seam*math.cos(a) + seam2*math.sin(a))*self.radii[ix] + point) points_rows.append(points) if debug: print(f"// Row: {', '.join([p.render() for p in points])}") elif (not self.make_torus) and ix == len(self.points) - 1: # End of the path v = point.sub(self.points[-2]) seam2 = v.cross(seam).norm() if debug: print(f"//End. v={v.render()} seam={seam.render()} seam2={seam2.render()}") points = [] for i in range(self.fn): a = math.pi*2*i/self.fn points.append((seam*math.cos(a) + seam2*math.sin(a))*self.radii[ix] + point) points_rows.append(points) if debug: print(f"// Row: {', '.join([p.render() for p in points])}") else: # Middle of the path iprev = ix - 1 if ix > 0 else len(self.points) - 1 inext = ix + 1 if ix < len(self.points) - 1 else 0 # (p[-1]) -va-> (p[0]) -vb-> (p[1]) va = point.sub(self.points[iprev]).norm() # vector incoming to this elbow vb = self.points[inext].sub(point).norm() # vector going out from this elbow if debug: print(f"//Middle. va={va.render()} vb={vb.render()}") # Get the vector perpendicular to va that points to the inside of the cylinder around va according # to the elbow at p[0]. This is the component of vb in a basis defined by va. vdot = va.dot(vb) vb_proj = va.scale(vdot) # The projection of vb onto va vb_perp = vb.sub(vb_proj) # This is perpendicular to va if debug: print(f"// vb_proj={vb_proj.render()} vb_perp={vb_perp.render()}") va_inner = vb_perp.norm() va_proj = vb.scale(vdot) va_perp = va.sub(va_proj) if debug: print(f"// va_proj={va_proj.render()} va_perp={va_perp.render()}") vb_inner = va_perp.scale(-1).norm() # Here we want to project -va onto vb if debug: print(f"// va_inner={va_inner.render()} vb_inner={vb_inner.render()}") if ix == 0: # We just choose a seam when making a torus seam_angle = 0 else: # The new seam on vb (seam_b) has the same angle to vb_inner as it had on va to va_inner seam_angle = seam.angle(va_inner, mode="rad") # need to figure out the sign of the angle if seam_angle != 0: if va_inner.cross(seam).dot(va) < 0: seam_angle = -seam_angle vb_inner2 = vb.cross(vb_inner).norm() seam_b = vb_inner*math.cos(seam_angle) + vb_inner2*math.sin(seam_angle) if debug: if ix == 0: print(f"// seam=N/A seam_b={seam_b.render()}") else: print(f"// seam={seam.render()} seam_b={seam_b.render()}") vangle = va.scale(-1).angle(vb, mode="rad") long_inner = (vb-va).norm().scale(1/math.sin(vangle/2)) # long_inner is the long axis of the elliptic intersection between the cylinders around va and vb short = va.cross(long_inner).norm() # the short axis of the ellipse if debug: print(f"// long_inner={long_inner.render()} short={short.render()} vangle={vangle/math.pi*180}(deg) seam_angle={seam_angle/math.pi*180}(deg)") points = [] for i in range(self.fn): # We draw the ellipse according to long_inner and short, but use seam_angle to get the right points a = math.pi*2*i/self.fn + seam_angle points.append((long_inner*math.cos(a) + short*math.sin(a))*self.radii[ix] + point) points_rows.append(points) if debug: print(f"// Row: {', '.join([p.render() for p in points])}") seam = seam_b return Polyhedron.tube(points=points_rows, convexity=self.convexity, make_torus=self.make_torus) def render(self) -> str: """Render the object into OpenSCAD code""" return self.process().render()Ancestors
Methods
def color(self, r, g, b, a=1.0) ‑> Object-
Apply a color and return a new object. See https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Transformations#color
def delta_offset(self, delta, chamfer=False)-
Inherited from:
Object.delta_offsetReturn a new 2D interior or exterior outline from an existing outline. See https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Transformations#offset
def diff(self,
tool: list | ForwardRef('Object')) ‑> Object-
Remove from the object using a difference operator, and return a new object. See …
def extrude(self, height, convexity=10, center: bool = False) ‑> Object-
Inherited from:
Object.extrudeApply a linear extrusion and return a new object. If
centeris false, the linear extrusion Z range is from 0 to height; if it is true, the range is … def intersection(self,
objects: list | ForwardRef('Object')) ‑> Object-
Inherited from:
Object.intersectionGet the intersection of self and an object of list of objects, and return a new object. See …
def move(self,
v: list | Point) ‑> Object-
Apply a translation and return a new object. Synonym of
translate() def process(self, debug: bool = False) ‑> Polyhedron-
Generate a Polyhedron object from the parameters
def radial_offset(self, r)-
Inherited from:
Object.radial_offsetReturn a new 2D interior or exterior outline from an existing outline. See https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Transformations#offset
def render(self) ‑> str-
Render the object into OpenSCAD code
def rotate(self,
a,
v: list | Point) ‑> Object-
Apply a rotation and return a new object. See https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Transformations#rotate
def rotate_extrude(self, angle, convexity=10) ‑> Object-
Inherited from:
Object.rotate_extrudeApply a rotational extrusion and return a new object. For all points x >= 0 must be true. See …
def scale(self,
v: list | Point | float) ‑> Object-
Apply scaling and return a new object. Accepts a vector (a Point object or a list of floats) or a single float for uniform scaling. See …
def translate(self,
v: list | Point) ‑> Object-
Inherited from:
Object.translateApply a translation and return a new object. See https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Transformations#translate
def union(self,
objects: list | ForwardRef('Object')) ‑> Object-
Form the union of self and an object or list of objects, and return a new object. See …