Source code for cam.utilities.shapely_utils
"""Fabex 'shapely_utils.py' © 2012 Vilem Novak
Functions to handle shapely operations and conversions - curve, coords, polygon
"""
from math import pi
import shapely
from shapely.geometry import polygon as spolygon
from shapely import geometry as sgeometry
from mathutils import Euler, Vector
try:
import bl_ext.blender_org.simplify_curves_plus as curve_simplify
except ImportError:
pass
from ..constants import SHAPELY
[docs]
def shapely_remove_doubles(p, optimize_threshold):
"""Remove duplicate points from the boundary of a shape.
This function simplifies the boundary of a given shape by removing
duplicate points using the Ramer-Douglas-Peucker algorithm. It iterates
through each contour of the shape, applies the simplification, and adds
the resulting contours to a new shape. The optimization threshold can be
adjusted to control the level of simplification.
Args:
p (Shape): The shape object containing boundaries to be simplified.
optimize_threshold (float): A threshold value that influences the
simplification process.
Returns:
Shape: A new shape object with simplified boundaries.
"""
optimize_threshold *= 0.000001
soptions = ["distance", "distance", 0.0, 5, optimize_threshold, 5, optimize_threshold]
for ci, c in enumerate(p.boundary): # in range(0,len(p)):
veclist = []
for v in c:
veclist.append(Vector((v[0], v[1])))
s = curve_simplify.simplify_RDP(veclist, soptions)
nc = []
for i in range(0, len(s)):
nc.append(c[s[i]])
if len(nc) > 2:
pnew.addContour(nc, p.isHole(ci))
else:
pnew.addContour(p[ci], p.isHole(ci))
return pnew
[docs]
def shapely_to_multipolygon(anydata):
"""Convert a Shapely geometry to a MultiPolygon.
This function takes a Shapely geometry object and converts it to a
MultiPolygon. If the input geometry is already a MultiPolygon, it
returns it as is. If the input is a Polygon and not empty, it wraps the
Polygon in a MultiPolygon. If the input is an empty Polygon, it returns
an empty MultiPolygon. For any other geometry type, it prints a message
indicating that the conversion was aborted and returns an empty
MultiPolygon.
Args:
anydata (shapely.geometry.base.BaseGeometry): A Shapely geometry object
Returns:
shapely.geometry.MultiPolygon: A MultiPolygon representation of the input
geometry.
"""
print("Geometry Type: ", anydata.geom_type)
print("Anydata Empty: ", anydata.is_empty)
## bug: empty mesh circle makes anydata empty: geometry type 'GeometryCollection'
if anydata.geom_type == "MultiPolygon":
return anydata
elif anydata.geom_type == "Polygon":
if not anydata.is_empty:
return shapely.geometry.MultiPolygon([anydata])
else:
return sgeometry.MultiPolygon()
else:
print("Shapely Conversion Aborted")
return sgeometry.MultiPolygon()
[docs]
def shapely_to_coordinates(anydata):
"""Convert a Shapely geometry object to a list of coordinates.
This function takes a Shapely geometry object and extracts its
coordinates based on the geometry type. It handles various types of
geometries including Polygon, MultiPolygon, LineString, MultiLineString,
and GeometryCollection. If the geometry is empty or of type MultiPoint,
it returns an empty list. The coordinates are returned in a nested list
format, where each sublist corresponds to the exterior or interior
coordinates of the geometries.
Args:
anydata (shapely.geometry.base.BaseGeometry): A Shapely geometry object
Returns:
list: A list of coordinates extracted from the input geometry.
The structure of the list depends on the geometry type.
"""
p = anydata
seq = []
if p.is_empty:
return seq
elif p.geom_type == "Polygon":
clen = len(p.exterior.coords)
seq = [p.exterior.coords]
for interior in p.interiors:
seq.append(interior.coords)
elif p.geom_type == "MultiPolygon":
clen = 0
seq = []
for sp in p.geoms:
clen += len(sp.exterior.coords)
seq.append(sp.exterior.coords)
for interior in sp.interiors:
seq.append(interior.coords)
elif p.geom_type == "MultiLineString":
seq = []
for linestring in p.geoms:
seq.append(linestring.coords)
elif p.geom_type == "LineString":
seq = []
seq.append(p.coords)
elif p.geom_type == "MultiPoint":
return
elif p.geom_type == "GeometryCollection":
clen = 0
seq = []
for sp in p.geoms: # TODO
clen += len(sp.exterior.coords)
seq.append(sp.exterior.coords)
for interior in sp.interiors:
seq.extend(interior.coords)
return seq
[docs]
def shapely_to_curve(name, p, z, cyclic=True):
"""Create a 3D curve object in Blender from a Shapely geometry.
This function takes a Shapely geometry and converts it into a 3D curve
object in Blender. It extracts the coordinates from the Shapely geometry
and creates a new curve object with the specified name. The curve is
created in the 3D space at the given z-coordinate, with a default weight
for the points.
Args:
name (str): The name of the curve object to be created.
p (shapely.geometry): A Shapely geometry object from which to extract
coordinates.
z (float): The z-coordinate for all points of the curve.
Returns:
bpy.types.Object: The newly created curve object in Blender.
"""
import bpy
import bmesh
from bpy_extras import object_utils
verts = []
edges = []
vi = 0
ci = 0
seq = shapely_to_coordinates(p)
w = 1 # weight
curvedata = bpy.data.curves.new(name=name, type="CURVE")
curvedata.dimensions = "3D"
objectdata = bpy.data.objects.new(name, curvedata)
objectdata.location = (0, 0, 0) # object origin
bpy.context.collection.objects.link(objectdata)
for c in seq:
polyline = curvedata.splines.new("POLY")
polyline.points.add(len(c) - 1)
for num in range(len(c)):
x, y = c[num][0], c[num][1]
polyline.points[num].co = (x, y, z, w)
bpy.context.view_layer.objects.active = objectdata
objectdata.select_set(state=True)
for c in objectdata.data.splines:
c.use_cyclic_u = cyclic
return objectdata # bpy.context.active_object
