add_curve_extra_objects/add_curve_braid.py

   1 # SPDX-FileCopyrightText: 2017-2022 Blender Foundation
   2 #
   3 # SPDX-License-Identifier: GPL-2.0-or-later
   4
   5 """
   6 bl_info = {
   7     "name": "New Braid",
   8     "author": "Jared Forsyth <github.com/jaredly>",
   9     "version": (1, 0, 3),
  10     "blender": (2, 80, 0),
  11     "location": "View3D > Add > Mesh > New Braid",
  12     "description": "Adds a new Braid",
  13     "warning": "",
  14     "doc_url": "{BLENDER_MANUAL_URL}/addons/add_curve/extra_objects.html",
  15     "category": "Add Mesh",
  16 }
  17 """
  18
  19 import bpy
  20 from bpy.props import (
  21         FloatProperty,
  22         IntProperty,
  23         BoolProperty,
  24         )
  25 from bpy.types import Operator
  26 from math import (
  27         sin, cos,
  28         pi,
  29         )
  30
  31
  32 def angle_point(center, angle, distance):
  33     cx, cy = center
  34     x = cos(angle) * distance
  35     y = sin(angle) * distance
  36     return x + cx, y + cy
  37
  38
  39 def flat_hump(strands, mx=1, my=1, mz=1, resolution=2):
  40     num = 4 * resolution
  41     dy = 2 * pi / num
  42     dz = 2 * pi * (strands - 1) / num
  43     for i in range(num):
  44         x = i * mx
  45         y = cos(i * dy) * my
  46         z = sin(i * dz) * mz
  47
  48         yield x, y, z
  49
  50
  51 def circle_hump(pos, strands, humps, radius=1, mr=1, mz=.2, resolution=2):
  52     num = 5 * resolution
  53     dt = 2 * pi / humps * strands / num
  54     dr = 2 * pi * (strands - 1) / num
  55     dz = 2 * pi / num
  56     t0 = 2 * pi / humps * pos
  57
  58     for i in range(num):
  59         x, y = angle_point((0, 0), i * dt + t0, radius + sin(i * dr) * mr)
  60         z = cos(i * dz) * mz
  61
  62         yield x, y, z
  63
  64
  65 def make_strands(strands, humps, radius=1, mr=1, mz=.2, resolution=2):
  66     positions = [0 for x in range(humps)]
  67     last = None
  68     lines = []
  69     at = 0
  70
  71     while 0 in positions:
  72         if positions[at]:
  73             at = positions.index(0)
  74             last = None
  75         hump = list(circle_hump(at, strands, humps, radius, mr, mz, resolution))
  76         if last is None:
  77             last = hump
  78             lines.append(last)
  79         else:
  80             last.extend(hump)
  81         positions[at] = 1
  82         at += strands
  83         at %= humps
  84
  85     return lines
  86
  87
  88 def poly_line(curve, points, join=True, type='NURBS'):
  89     polyline = curve.splines.new(type)
  90     polyline.points.add(len(points) - 1)
  91     for num in range(len(points)):
  92         polyline.points[num].co = (points[num]) + (1,)
  93
  94     polyline.order_u = len(polyline.points) - 1
  95     if join:
  96         polyline.use_cyclic_u = True
  97
  98
  99 def poly_lines(objname, curvename, lines, bevel=None, joins=False, ctype='NURBS'):
 100     curve = bpy.data.curves.new(name=curvename, type='CURVE')
 101     curve.dimensions = '3D'
 102     curve.fill_mode = 'FULL'
 103
 104     obj = bpy.data.objects.new(objname, curve)
 105     obj.location = (0, 0, 0)  # object origin
 106
 107     for i, line in enumerate(lines):
 108         poly_line(curve, line, joins if type(joins) == bool else joins[i], type=ctype)
 109
 110     if bevel:
 111         curve.bevel_object = bpy.data.objects[bevel]
 112     return obj
 113
 114
 115 def nurbs_circle(name, w, h):
 116     pts = [(-w / 2, 0, 0), (0, -h / 2, 0), (w / 2, 0, 0), (0, h / 2, 0)]
 117     return poly_lines(name, name + '_curve', [pts], joins=True)
 118
 119
 120 def star_pts(r=1, ir=None, points=5, center=(0, 0)):
 121     """
 122     Create points for a star. They are 2d - z is always zero
 123
 124     r: the outer radius
 125     ir: the inner radius
 126     """
 127     if not ir:
 128         ir = r / 5
 129     pts = []
 130     dt = pi * 2 / points
 131     for i in range(points):
 132         t = i * dt
 133         ti = (i + .5) * dt
 134         pts.append(angle_point(center, t, r) + (0,))
 135         pts.append(angle_point(center, ti, ir) + (0,))
 136     return pts
 137
 138
 139 def defaultCircle(w=.6):
 140     circle = nurbs_circle('braid_circle', w, w)
 141     circle.hide_select = True
 142     return circle
 143
 144
 145 def defaultStar():
 146     star = poly_lines('star', 'staz', [tuple(star_pts(points=5, r=.5, ir=.05))], type='NURBS')
 147     star.hide_select = True
 148     return star
 149
 150
 151 def awesome_braid(strands=3, sides=5, bevel='braid_circle', pointy=False, **kwds):
 152     lines = make_strands(strands, sides, **kwds)
 153     types = {True: 'POLY', False: 'NURBS'}[pointy]
 154     return poly_lines('Braid', 'Braid_c', lines, bevel=bevel, joins=True, ctype=types)
 155
 156
 157 class Braid(Operator):
 158     bl_idname = "curve.add_braid"
 159     bl_label = "New Braid"
 160     bl_description = ("Construct a new Braid\n"
 161                       "Creates two objects - the hidden one is used as the Bevel control")
 162     bl_options = {'REGISTER', 'UNDO', 'PRESET'}
 163
 164     strands : IntProperty(
 165             name="Strands",
 166             description="Number of Strands",
 167             min=2, max=100,
 168             default=3
 169             )
 170     sides : IntProperty(
 171             name="Sides",
 172             description="Number of Knot sides",
 173             min=2, max=100,
 174             default=5
 175             )
 176     radius : FloatProperty(
 177             name="Radius",
 178             description="Increase / decrease the diameter in X,Y axis",
 179             default=1
 180             )
 181     thickness : FloatProperty(
 182             name="Thickness",
 183             description="The ratio between inner and outside diameters",
 184             default=.3
 185             )
 186     strandsize : FloatProperty(
 187             name="Bevel Depth",
 188             description="Individual strand diameter (similar to Curve's Bevel depth)",
 189             default=.3,
 190             min=.01, max=10
 191             )
 192     width : FloatProperty(
 193             name="Width",
 194             description="Stretch the Braids along the Z axis",
 195             default=.2
 196             )
 197     resolution : IntProperty(
 198             name="Bevel Resolution",
 199             description="Resolution of the Created curve\n"
 200                         "Increasing this value, will produce heavy geometry",
 201             min=1,
 202             max=100, soft_max=24,
 203             default=2
 204             )
 205     pointy : BoolProperty(
 206             name="Pointy",
 207             description="Switch between round and sharp corners",
 208             default=False
 209             )
 210     edit_mode : BoolProperty(
 211             name="Show in edit mode",
 212             default=True,
 213             description="Show in edit mode"
 214             )
 215
 216     def draw(self, context):
 217         layout = self.layout
 218
 219         box = layout.box()
 220         col = box.column(align=True)
 221         col.label(text="Settings:")
 222         col.prop(self, "strands")
 223         col.prop(self, "sides")
 224
 225         col = box.column(align=True)
 226         col.prop(self, "radius")
 227         col.prop(self, "thickness")
 228         col.prop(self, "width")
 229
 230         col = box.column()
 231         col.prop(self, "pointy")
 232
 233         box = layout.box()
 234         col = box.column(align=True)
 235         col.label(text="Geometry Options:")
 236         col.prop(self, "strandsize")
 237         col.prop(self, "resolution")
 238
 239         col = layout.column()
 240         col.row().prop(self, "edit_mode", expand=True)
 241
 242     def execute(self, context):
 243          # turn off 'Enter Edit Mode'
 244         use_enter_edit_mode = bpy.context.preferences.edit.use_enter_edit_mode
 245         bpy.context.preferences.edit.use_enter_edit_mode = False
 246
 247         circle = defaultCircle(self.strandsize)
 248         context.scene.collection.objects.link(circle)
 249         braid = awesome_braid(
 250                         self.strands, self.sides,
 251                         bevel=circle.name,
 252                         pointy=self.pointy,
 253                         radius=self.radius,
 254                         mr=self.thickness,
 255                         mz=self.width,
 256                         resolution=self.resolution
 257                         )
 258         base = context.scene.collection.objects.link(braid)
 259
 260         for ob in context.scene.objects:
 261             ob.select_set(False)
 262         braid.select_set(True)
 263         bpy.context.view_layer.objects.active = braid
 264
 265         if use_enter_edit_mode:
 266             bpy.ops.object.mode_set(mode = 'EDIT')
 267
 268         # restore pre operator state
 269         bpy.context.preferences.edit.use_enter_edit_mode = use_enter_edit_mode
 270
 271         if self.edit_mode:
 272             bpy.ops.object.mode_set(mode = 'EDIT')
 273         else:
 274             bpy.ops.object.mode_set(mode = 'OBJECT')
 275
 276         return {'FINISHED'}
 277
 278
 279 def register():
 280     bpy.utils.register_class(Braid)
 281
 282
 283 def unregister():
 284     bpy.utils.unregister_class(Braid)
 285
 286
 287 if __name__ == "__main__":
 288     register()