カーブ生成 ＋ 渦巻き (blender 2.82a)

uzumaki.py

import bpy
import math

# カーブ生成 ＋ 渦巻き (blender 2.82a)
# (渦巻きは曲線上の点をプロットしたもので、NURBSのポイントとして適切かは考慮していません。）

def createPolyline(coords, obj_name, closed=False):
    # ref: https://blender.stackexchange.com/questions/120074/how-to-make-a-curve-path-from-scratch-given-a-list-of-x-y-z-points
    cv = bpy.data.curves.new('cv', 'CURVE')
    cv.dimensions = '3D'

    spline = cv.splines.new(type='NURBS')  # 'POLY', 'BEZIER', 'BSPLINE', 'CARDINAL', 'NURBS'
    spline.points.add(len(coords) - 1)
    spline.use_cyclic_u = closed

    for p, co in zip(spline.points, coords):
        p.co = co + [1.0]
        
    obj = bpy.data.objects.new(obj_name, cv)
    bpy.context.scene.collection.objects.link(obj)
    return obj


def uzumaki1():
    # 渦巻き。点がだいたい等間隔になる描き方
    coords = []
    r = t = 0.0
    y = 2.0
    m = 1.0
    for i in range(100):
        coords.append([math.cos(t) * r, math.sin(t) * r, 0])
        t += math.atan2(y, r) * m
        r += y / t * m
    return createPolyline(coords, "uzumaki1")

def uzumaki2():
    # 渦巻き。オーソドックスな数式による描き方
    coords = []
    t = 0.0
    t_incr = 0.2
    for i in range(100):
        coords.append([math.cos(t) * t, math.sin(t) * t, 0])
        t += t_incr
    return createPolyline(coords, "uzumaki2")

uzu = uzumaki1()
#uzu = uzumaki2()
uzu.data.bevel_depth = 1.0