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mightyscape-1.1-deprecated/extensions/fablabchemnitz/paperfold/paperfold.py

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49 KiB
Python

#!/usr/bin/env python3
import math
import inkex
from inkex import Transform, TextElement, Tspan, Color, Circle, PathElement, CubicSuperPath
import tempfile
import os
import random
import numpy as np
import openmesh as om
import networkx as nx
from lxml import etree
import copy
"""
Extension for InkScape 1.0
Paperfold is another flattener for triangle mesh files, heavily based on paperfoldmodels by Felix Scholz aka felixfeliz.
Author: Mario Voigt / FabLab Chemnitz
Mail: mario.voigt@stadtfabrikanten.org
Date: 13.09.2020
Last patch: 10.05.2021
License: GNU GPL v3
To run this you need to install OpenMesh with python pip.
The algorithm of paperfoldmodels consists of three steps:
- Find a minimum spanning tree of the dual graph of the mesh.
- Unfold the dual graph.
- Remove self-intersections by adding additional cuts along edges.
Reference: The code is mostly based on the algorithm presented in a by Straub and Prautzsch (https://geom.ivd.kit.edu/downloads/proj-paper-models_cut_out_sheets.pdf).
Module licenses
- paperfoldmodels (https://github.com/felixfeliz/paperfoldmodels) - MIT License
possible import file types -> https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-8.0-Documentation/a04096.html
todo:
- option to render all triangles in a detached way (overlapping lines/independent) + merge coplanar adjacent triangles to polygons
- write tab and slot generator (like joinery/polyhedra extension)
- fstl preview
- fix line: dualGraph.add_edge(face1.idx(), face2.idx(), idx=edge.idx(), weight=edgeweight) # #might fail without throwing any error (silent aborts) ...
- option to set fill color per face
- add some way to merge coplanar triangles (tri-faces) to polygons and keep those polygons (facets) intact. At the moment facets are getting destroyed. Not good for some papercrafts
"""
class Paperfold(inkex.EffectExtension):
angleRangeCalculated = False #set to true after first calculation iteration (needed globally)
minAngle = 0
minAngle = 0
angleRange = 0
# Compute the third point of a triangle when two points and all edge lengths are given
def getThirdPoint(self, v0, v1, l01, l12, l20):
v2rotx = (l01 ** 2 + l20 ** 2 - l12 ** 2) / (2 * l01)
val = (l01 + l20 + l12) * (l01 + l20 - l12) * (l01 - l20 + l12) * (-l01 + l20 + l12)
v2roty0 = np.sqrt(abs(val)) / (2 * l01)
v2roty1 = - v2roty0
theta = np.arctan2(v1[1] - v0[1], v1[0] - v0[0])
v2trans0 = np.array(
[v2rotx * np.cos(theta) - v2roty0 * np.sin(theta), v2rotx * np.sin(theta) + v2roty0 * np.cos(theta), 0])
v2trans1 = np.array(
[v2rotx * np.cos(theta) - v2roty1 * np.sin(theta), v2rotx * np.sin(theta) + v2roty1 * np.cos(theta), 0])
return [v2trans0 + v0, v2trans1 + v0]
# Check if two lines intersect
def lineIntersection(self, v1, v2, v3, v4, epsilon):
d = (v4[1] - v3[1]) * (v2[0] - v1[0]) - (v4[0] - v3[0]) * (v2[1] - v1[1])
u = (v4[0] - v3[0]) * (v1[1] - v3[1]) - (v4[1] - v3[1]) * (v1[0] - v3[0])
v = (v2[0] - v1[0]) * (v1[1] - v3[1]) - (v2[1] - v1[1]) * (v1[0] - v3[0])
if d < 0:
u, v, d = -u, -v, -d
return ((0 + epsilon) <= u <= (d - epsilon)) and ((0 + epsilon) <= v <= (d - epsilon))
# Check if a point lies inside a triangle
def pointInTriangle(self, A, B, C, P, epsilon):
v0 = [C[0] - A[0], C[1] - A[1]]
v1 = [B[0] - A[0], B[1] - A[1]]
v2 = [P[0] - A[0], P[1] - A[1]]
cross = lambda u, v: u[0] * v[1] - u[1] * v[0]
u = cross(v2, v0)
v = cross(v1, v2)
d = cross(v1, v0)
if d < 0:
u, v, d = -u, -v, -d
return u >= (0 + epsilon) and v >= (0 + epsilon) and (u + v) <= (d - epsilon)
# Check if two triangles intersect
def triangleIntersection(self, t1, t2, epsilon):
if self.lineIntersection(t1[0], t1[1], t2[0], t2[1], epsilon): return True
if self.lineIntersection(t1[0], t1[1], t2[0], t2[2], epsilon): return True
if self.lineIntersection(t1[0], t1[1], t2[1], t2[2], epsilon): return True
if self.lineIntersection(t1[0], t1[2], t2[0], t2[1], epsilon): return True
if self.lineIntersection(t1[0], t1[2], t2[0], t2[2], epsilon): return True
if self.lineIntersection(t1[0], t1[2], t2[1], t2[2], epsilon): return True
if self.lineIntersection(t1[1], t1[2], t2[0], t2[1], epsilon): return True
if self.lineIntersection(t1[1], t1[2], t2[0], t2[2], epsilon): return True
if self.lineIntersection(t1[1], t1[2], t2[1], t2[2], epsilon): return True
inTri = True
inTri = inTri and self.pointInTriangle(t1[0], t1[1], t1[2], t2[0], epsilon)
inTri = inTri and self.pointInTriangle(t1[0], t1[1], t1[2], t2[1], epsilon)
inTri = inTri and self.pointInTriangle(t1[0], t1[1], t1[2], t2[2], epsilon)
if inTri == True: return True
inTri = True
inTri = inTri and self.pointInTriangle(t2[0], t2[1], t2[2], t1[0], epsilon)
inTri = inTri and self.pointInTriangle(t2[0], t2[1], t2[2], t1[1], epsilon)
inTri = inTri and self.pointInTriangle(t2[0], t2[1], t2[2], t1[2], epsilon)
if inTri == True: return True
return False
# Functions for visualisation and output
def addVisualisationData(self, mesh, unfoldedMesh, originalHalfedges, unfoldedHalfedges, glueNumber, dihedralAngles):
for i in range(3):
dihedralAngles[unfoldedMesh.edge_handle(unfoldedHalfedges[i]).idx()] = round(math.degrees(mesh.calc_dihedral_angle(originalHalfedges[i])), self.options.roundingDigits)
# Information, which edges belong together
glueNumber[unfoldedMesh.edge_handle(unfoldedHalfedges[i]).idx()] = mesh.edge_handle(originalHalfedges[i]).idx()
# Function that unwinds a spanning tree
def unfoldSpanningTree(self, mesh, spanningTree):
try:
unfoldedMesh = om.TriMesh() # the unfolded mesh
numFaces = mesh.n_faces()
sizeTree = spanningTree.number_of_edges()
numUnfoldedEdges = 3 * numFaces - sizeTree
isFoldingEdge = np.zeros(numUnfoldedEdges, dtype=bool) # Indicates whether an edge is folded or cut
glueNumber = np.empty(numUnfoldedEdges, dtype=int) # Saves with which edge is glued together
dihedralAngles = np.empty(numUnfoldedEdges, dtype=float) # Valley folding or mountain folding
connections = np.empty(numFaces, dtype=int) # Saves which original triangle belongs to the unrolled one
numFaces = mesh.n_faces()
sizeTree = spanningTree.number_of_edges()
numUnfoldedEdges = 3 * numFaces - sizeTree
# Select the first triangle as desired
startingNode = list(spanningTree.nodes())[0]
startingTriangle = mesh.face_handle(startingNode)
# We unwind the first triangle
# All half edges of the first triangle
firstHalfEdge = mesh.halfedge_handle(startingTriangle)
secondHalfEdge = mesh.next_halfedge_handle(firstHalfEdge)
thirdHalfEdge = mesh.next_halfedge_handle(secondHalfEdge)
originalHalfEdges = [firstHalfEdge, secondHalfEdge, thirdHalfEdge]
# Calculate the lengths of the edges, this will determine the shape of the triangle (congruence)
edgelengths = [mesh.calc_edge_length(firstHalfEdge), mesh.calc_edge_length(secondHalfEdge),
mesh.calc_edge_length(thirdHalfEdge)]
# The first two points
firstUnfoldedPoint = np.array([0, 0, 0])
secondUnfoldedPoint = np.array([edgelengths[0], 0, 0])
# We calculate the third point of the triangle from the first two. There are two possibilities
[thirdUnfolded0, thirdUnfolded1] = self.getThirdPoint(firstUnfoldedPoint, secondUnfoldedPoint, edgelengths[0],
edgelengths[1],
edgelengths[2])
if thirdUnfolded0[1] > 0:
thirdUnfoldedPoint = thirdUnfolded0
else:
thirdUnfoldePoint = thirdUnfolded1
# Add the new corners to the unwound net
firstUnfoldedVertex = unfoldedMesh.add_vertex(secondUnfoldedPoint)
secondUnfoldedVertex = unfoldedMesh.add_vertex(thirdUnfoldedPoint)
thirdUnfoldedVertex = unfoldedMesh.add_vertex(firstUnfoldedPoint)
#firstUnfoldedVertex = unfoldedMesh.add_vertex(firstUnfoldedPoint)
#secondUnfoldedVertex = unfoldedMesh.add_vertex(secondUnfoldedPoint)
#thirdUnfoldedVertex = unfoldedMesh.add_vertex(thirdUnfoldedPoint)
# Create the page
unfoldedFace = unfoldedMesh.add_face(firstUnfoldedVertex, secondUnfoldedVertex, thirdUnfoldedVertex)
# Memory properties of the surface and edges
# The half edges in unrolled mesh
firstUnfoldedHalfEdge = unfoldedMesh.opposite_halfedge_handle(unfoldedMesh.halfedge_handle(firstUnfoldedVertex))
secondUnfoldedHalfEdge = unfoldedMesh.next_halfedge_handle(firstUnfoldedHalfEdge)
thirdUnfoldedHalfEdge = unfoldedMesh.next_halfedge_handle(secondUnfoldedHalfEdge)
unfoldedHalfEdges = [firstUnfoldedHalfEdge, secondUnfoldedHalfEdge, thirdUnfoldedHalfEdge]
# Associated triangle in 3D mesh
connections[unfoldedFace.idx()] = startingTriangle.idx()
# Folding direction and adhesive number
self.addVisualisationData(mesh, unfoldedMesh, originalHalfEdges, unfoldedHalfEdges, glueNumber, dihedralAngles)
if self.angleRangeCalculated is False:
self.minAngle = min(dihedralAngles)
self.maxAngle = max(dihedralAngles)
#sometimes weird large value are returned, like -34345645435464565453356788761029782
if self.minAngle < -180.0:
self.minAngle = -180.0
if self.maxAngle > 180.0:
self.maxAngle = 180.0
self.angleRange = self.maxAngle - self.minAngle
#self.msg(minAngle)
#self.msg(maxAngle)
#self.msg(angleRange)
self.angleRangeCalculated = True
halfEdgeConnections = {firstHalfEdge.idx(): firstUnfoldedHalfEdge.idx(),
secondHalfEdge.idx(): secondUnfoldedHalfEdge.idx(),
thirdHalfEdge.idx(): thirdUnfoldedHalfEdge.idx()}
# We walk through the tree
for dualEdge in nx.dfs_edges(spanningTree, source=startingNode):
try:
foldingEdge = mesh.edge_handle(spanningTree[dualEdge[0]][dualEdge[1]]['idx'])
# Find the corresponding half edge in the output triangle
foldingHalfEdge = mesh.halfedge_handle(foldingEdge, 0)
if not (mesh.face_handle(foldingHalfEdge).idx() == dualEdge[0]):
foldingHalfEdge = mesh.halfedge_handle(foldingEdge, 1)
# Find the corresponding unwound half edge
unfoldedLastHalfEdge = unfoldedMesh.halfedge_handle(halfEdgeConnections[foldingHalfEdge.idx()])
# Find the point in the unrolled triangle that is not on the folding edge
oppositeUnfoldedVertex = unfoldedMesh.to_vertex_handle(unfoldedMesh.next_halfedge_handle(unfoldedLastHalfEdge))
# We turn the half edges over to lie in the new triangle
foldingHalfEdge = mesh.opposite_halfedge_handle(foldingHalfEdge)
unfoldedLastHalfEdge = unfoldedMesh.opposite_halfedge_handle(unfoldedLastHalfEdge)
# The two corners of the folding edge
unfoldedFromVertex = unfoldedMesh.from_vertex_handle(unfoldedLastHalfEdge)
unfoldedToVertex = unfoldedMesh.to_vertex_handle(unfoldedLastHalfEdge)
# Calculate the edge lengths in the new triangle
secondHalfEdgeInFace = mesh.next_halfedge_handle(foldingHalfEdge)
thirdHalfEdgeInFace = mesh.next_halfedge_handle(secondHalfEdgeInFace)
originalHalfEdges = [foldingHalfEdge, secondHalfEdgeInFace, thirdHalfEdgeInFace]
edgelengths = [mesh.calc_edge_length(foldingHalfEdge), mesh.calc_edge_length(secondHalfEdgeInFace),
mesh.calc_edge_length(thirdHalfEdgeInFace)]
# We calculate the two possibilities for the third point in the triangle
[newUnfoldedVertex0, newUnfoldedVertex1] = self.getThirdPoint(unfoldedMesh.point(unfoldedFromVertex),
unfoldedMesh.point(unfoldedToVertex), edgelengths[0],
edgelengths[1], edgelengths[2])
newUnfoldedVertex = unfoldedMesh.add_vertex(newUnfoldedVertex0)
# Make the face
newface = unfoldedMesh.add_face(unfoldedFromVertex, unfoldedToVertex, newUnfoldedVertex)
secondUnfoldedHalfEdge = unfoldedMesh.next_halfedge_handle(unfoldedLastHalfEdge)
thirdUnfoldedHalfEdge = unfoldedMesh.next_halfedge_handle(secondUnfoldedHalfEdge)
unfoldedHalfEdges = [unfoldedLastHalfEdge, secondUnfoldedHalfEdge, thirdUnfoldedHalfEdge]
# Saving the information about edges and page
# Dotted one's in the output
unfoldedLastEdge = unfoldedMesh.edge_handle(unfoldedLastHalfEdge)
isFoldingEdge[unfoldedLastEdge.idx()] = True
# Gluing number and folding direction
self.addVisualisationData(mesh, unfoldedMesh, originalHalfEdges, unfoldedHalfEdges, glueNumber, dihedralAngles)
# Related page
connections[newface.idx()] = dualEdge[1]
# Identify the half edges
for i in range(3):
halfEdgeConnections[originalHalfEdges[i].idx()] = unfoldedHalfEdges[i].idx()
except Exception as e:
inkex.utils.debug("Error walking the dual tree at dualEdge {}".format(e))
exit(1)
return [unfoldedMesh, isFoldingEdge, connections, glueNumber, dihedralAngles]
except Exception as e:
inkex.utils.debug("Error: model could not be unfolded. Check for:")
inkex.utils.debug(" - watertight model / intact hull")
inkex.utils.debug(" - duplicated edges or faces")
inkex.utils.debug(" - detached faces or holes")
inkex.utils.debug(" - missing units")
inkex.utils.debug(" - missing coordinate system")
inkex.utils.debug(" - multiple bodies in one file")
exit(1)
def unfold(self, mesh):
# Calculate the number of surfaces, edges and corners, as well as the length of the longest shortest edge
numEdges = mesh.n_edges()
numVertices = mesh.n_vertices()
numFaces = mesh.n_faces()
if numFaces > self.options.maxNumFaces:
inkex.utils.debug("Aborted. Target STL file has " + str(numFaces) + " faces, but only " + str( self.options.maxNumFaces) + " are allowed.")
exit(1)
if self.options.printStats is True:
inkex.utils.debug("Input STL mesh stats:")
inkex.utils.debug("* Number of edges: " + str(numEdges))
inkex.utils.debug("* Number of vertices: " + str(numVertices))
inkex.utils.debug("* Number of faces: " + str(numFaces))
inkex.utils.debug("-----------------------------------------------------------")
# Generate the dual graph of the mesh and calculate the weights
dualGraph = nx.Graph()
# For the weights: calculate the longest and shortest edge of the triangle
minLength = 1000
maxLength = 0
for edge in mesh.edges():
edgelength = mesh.calc_edge_length(edge)
if edgelength < minLength:
minLength = edgelength
if edgelength > maxLength:
maxLength = edgelength
# All edges in the net
for edge in mesh.edges():
#inkex.utils.debug("edge.idx = " + str(edge.idx()))
# The two sides adjacent to the edge
face1 = mesh.face_handle(mesh.halfedge_handle(edge, 0))
face2 = mesh.face_handle(mesh.halfedge_handle(edge, 1))
# The weight
edgeweight = 1.0 - (mesh.calc_edge_length(edge) - minLength) / (maxLength - minLength)
if self.options.experimentalWeights is True:
if round(math.degrees(mesh.calc_dihedral_angle(edge)), self.options.roundingDigits) > 0:
edgeweight = 1.0 - (mesh.calc_edge_length(edge) - minLength) / (maxLength - minLength)
if round(math.degrees(mesh.calc_dihedral_angle(edge)), self.options.roundingDigits) < 0:
edgeweight = -(1.0 - (mesh.calc_edge_length(edge) - minLength) / (maxLength - minLength))
if round(math.degrees(mesh.calc_dihedral_angle(edge)), self.options.roundingDigits) == 0:
edgeweight = 0.0
#inkex.utils.debug("edgeweight = " + str(edgeweight))
# Calculate the centres of the pages (only necessary for visualisation)
center1 = (0, 0)
for vertex in mesh.fv(face1):
center1 = center1 + 0.3333333333333333 * np.array([mesh.point(vertex)[0], mesh.point(vertex)[2]])
center2 = (0, 0)
for vertex in mesh.fv(face2):
center2 = center2 + 0.3333333333333333 * np.array([mesh.point(vertex)[0], mesh.point(vertex)[2]])
# Add the new nodes and edge to the dual graph
dualGraph.add_node(face1.idx(), pos=center1)
dualGraph.add_node(face2.idx(), pos=center2)
dualGraph.add_edge(face1.idx(), face2.idx(), idx=edge.idx(), weight=edgeweight) # #might fail without throwing any error ...
# Calculate the minimum spanning tree
spanningTree = nx.minimum_spanning_tree(dualGraph)
# Unfold the tree
fullUnfolding = self.unfoldSpanningTree(mesh, spanningTree)
[unfoldedMesh, isFoldingEdge, connections, glueNumber, dihedralAngles] = fullUnfolding
# Resolve the intersections
# Find all intersections
epsilon = 1E-12 # Accuracy
faceIntersections = []
for face1 in unfoldedMesh.faces():
for face2 in unfoldedMesh.faces():
if face2.idx() < face1.idx(): # so that we do not double check the couples
# Get the triangle faces
triangle1 = []
triangle2 = []
for halfedge in unfoldedMesh.fh(face1):
triangle1.append(unfoldedMesh.point(unfoldedMesh.from_vertex_handle(halfedge)))
for halfedge in unfoldedMesh.fh(face2):
triangle2.append(unfoldedMesh.point(unfoldedMesh.from_vertex_handle(halfedge)))
if self.triangleIntersection(triangle1, triangle2, epsilon):
faceIntersections.append([connections[face1.idx()], connections[face2.idx()]])
# Find the paths
# We find the minimum number of cuts to resolve any self-intersection
# Search all paths between overlapping triangles
paths = []
for intersection in faceIntersections:
paths.append(
nx.algorithms.shortest_paths.shortest_path(spanningTree, source=intersection[0], target=intersection[1]))
# Find all edges in all threads
edgepaths = []
for path in paths:
edgepath = []
for i in range(len(path) - 1):
edgepath.append((path[i], path[i + 1]))
edgepaths.append(edgepath)
# List of all edges in all paths
allEdgesInPaths = list(set().union(*edgepaths))
# Count how often each edge occurs
numEdgesInPaths = []
for edge in allEdgesInPaths:
num = 0
for path in edgepaths:
if edge in path:
num = num + 1
numEdgesInPaths.append(num)
S = []
C = []
while len(C) != len(paths):
# Calculate the weights to decide which edge to cut
cutWeights = np.empty(len(allEdgesInPaths))
for i in range(len(allEdgesInPaths)):
currentEdge = allEdgesInPaths[i]
# Count how many of the paths in which the edge occurs have already been cut
numInC = 0
for path in C:
if currentEdge in path:
numInC = numInC + 1
# Determine the weight
if (numEdgesInPaths[i] - numInC) > 0:
cutWeights[i] = 1 / (numEdgesInPaths[i] - numInC)
else:
cutWeights[i] = 1000 # 1000 = infinite
# Find the edge with the least weight
minimalIndex = np.argmin(cutWeights)
S.append(allEdgesInPaths[minimalIndex])
# Find all paths where the edge occurs and add them to C
for path in edgepaths:
if allEdgesInPaths[minimalIndex] in path and not path in C:
C.append(path)
# Now we remove the cut edges from the minimum spanning tree
spanningTree.remove_edges_from(S)
# Find the cohesive components
connectedComponents = nx.algorithms.components.connected_components(spanningTree)
connectedComponentList = list(connectedComponents)
# Unfolding of the components
unfoldings = []
for component in connectedComponentList:
unfoldings.append(self.unfoldSpanningTree(mesh, spanningTree.subgraph(component)))
return fullUnfolding, unfoldings
def findBoundingBox(self, mesh):
firstpoint = mesh.point(mesh.vertex_handle(0))
xmin = firstpoint[0]
xmax = firstpoint[0]
ymin = firstpoint[1]
ymax = firstpoint[1]
for vertex in mesh.vertices():
coordinates = mesh.point(vertex)
if (coordinates[0] < xmin):
xmin = coordinates[0]
if (coordinates[0] > xmax):
xmax = coordinates[0]
if (coordinates[1] < ymin):
ymin = coordinates[1]
if (coordinates[1] > ymax):
ymax = coordinates[1]
boxSize = np.maximum(np.abs(xmax - xmin), np.abs(ymax - ymin))
return [xmin, ymin, boxSize]
def writeSVG(self, unfolding, size, randomColorSet):
mesh = unfolding[0]
isFoldingEdge = unfolding[1]
glueNumber = unfolding[3]
dihedralAngles = unfolding[4]
#statistic values
gluePairs = 0
cuts = 0
coplanarEdges = 0
mountainFolds = 0
valleyFolds = 0
# Calculate the bounding box
[xmin, ymin, boxSize] = self.findBoundingBox(unfolding[0])
if size > 0:
boxSize = size
strokewidth = boxSize * self.options.fontSize / 8000
dashLength = boxSize * self.options.fontSize / 2000
spaceLength = boxSize * self.options.fontSize / 800
textDistance = boxSize * self.options.fontSize / 800
textStrokeWidth = boxSize * self.options.fontSize / 3000
fontsize = boxSize * self.options.fontSize / 1000
# Grouping
uniqueMainId = self.svg.get_unique_id("")
paperfoldPageGroup = self.document.getroot().add(inkex.Group(id=uniqueMainId + "-paperfold-page"))
textGroup = inkex.Group(id=uniqueMainId + "-text")
edgesGroup = inkex.Group(id=uniqueMainId + "-edges")
paperfoldPageGroup.add(textGroup)
paperfoldPageGroup.add(edgesGroup)
textFacesGroup = inkex.Group(id=uniqueMainId + "-textFaces")
textEdgesGroup = inkex.Group(id=uniqueMainId + "-textEdges")
textGroup.add(textFacesGroup)
textGroup.add(textEdgesGroup)
#we could write the unfolded mesh as a 2D stl file to disk if we like:
if self.options.writeTwoDSTL is True:
if not os.path.exists(self.options.TwoDSTLdir):
inkex.utils.debug("Export location for 2D STL unfoldings does not exist. Please select a another dir and try again.")
exit(1)
else:
om.write_mesh(os.path.join(self.options.TwoDSTLdir, uniqueMainId + "-paperfold-page.stl"), mesh)
#########################################################
# Nmbering triangle faces with circle around
#########################################################
if self.options.printTriangleNumbers is True:
for face in mesh.faces():
centroid = mesh.calc_face_centroid(face)
textFaceGroup = inkex.Group(id=uniqueMainId + "-textFace-" + str(face.idx()))
circle = textFaceGroup.add(Circle(cx="{:0.6f}".format(centroid[0]), cy="{:0.6f}".format(centroid[1]), r="{:0.6f}".format(fontsize)))
circle.set('id', uniqueMainId + "-textFaceCricle-" + str(face.idx()))
circle.set("style", "stroke:#000000;stroke-width:{:0.6f}".format(strokewidth/2) + ";fill:none")
text = textFaceGroup.add(TextElement(id=uniqueMainId + "-textFaceNumber-" + str(face.idx())))
text.set("x", "{:0.6f}".format(centroid[0]))
text.set("y", "{:0.6f}".format(centroid[1] + fontsize / 3))
text.set("font-size", "{:0.6f}".format(fontsize))
text.set("style", "stroke-width {:0.6f}".format(textStrokeWidth) + ";text-anchor:middle;text-align:center")
tspan = text.add(Tspan(id=uniqueMainId + "-textFaceNumberTspan-" + str(face.idx())))
tspan.set("x", "{:0.6f}".format(centroid[0]))
tspan.set("y", "{:0.6f}".format(centroid[1] + fontsize / 3))
tspan.set("style", "stroke-width {:0.6f}".format(textStrokeWidth) + ";text-anchor:middle;text-align:center")
tspan.text = str(face.idx())
textFacesGroup.append(textFaceGroup)
#########################################################
# Nmbering triangle edges and style them according to their type
#########################################################
# Go over all edges of the grid
for edge in mesh.edges():
# The two endpoints
he = mesh.halfedge_handle(edge, 0)
vertex0 = mesh.point(mesh.from_vertex_handle(he))
vertex1 = mesh.point(mesh.to_vertex_handle(he))
# Write a straight line between the two corners
line = edgesGroup.add(PathElement())
line.set('d', "M {:0.6f},{:0.6f} {:0.6f},{:0.6f}".format(vertex0[0], vertex0[1], vertex1[0], vertex1[1]))
# Colour depending on folding direction
lineStyle = {"fill": "none"}
lineStyle.update({"stroke": self.options.colorCutEdges})
line.set("id", uniqueMainId + "-cut-edge-" + str(edge.idx()))
lineStyle.update({"stroke-width": "{:0.6f}".format(strokewidth)})
lineStyle.update({"stroke-linecap":"butt"})
lineStyle.update({"stroke-linejoin":"miter"})
lineStyle.update({"stroke-miterlimit":"4"})
dihedralAngle = dihedralAngles[edge.idx()]
# Dotted lines for folding edges
if isFoldingEdge[edge.idx()]:
if self.options.dashes is True:
lineStyle.update({"stroke-dasharray":"{:0.6f}, {:0.6f}".format(dashLength, spaceLength)})
if dihedralAngle > 0:
lineStyle.update({"stroke": self.options.colorMountainFolds})
line.set("id", uniqueMainId + "-mountain-fold-" + str(edge.idx()))
mountainFolds += 1
if dihedralAngle < 0:
lineStyle.update({"stroke": self.options.colorValleyFolds})
line.set("id", uniqueMainId + "-valley-fold-" + str(edge.idx()))
valleyFolds += 1
if dihedralAngle == 0:
lineStyle.update({"stroke": self.options.colorCoplanarEdges})
line.set("id", uniqueMainId + "-coplanar-edge-" + str(edge.idx()))
if self.options.importCoplanarEdges is False:
line.delete()
coplanarEdges += 1
else:
lineStyle.update({"stroke-dasharray":"none"})
# The number of the edge to be glued
if not isFoldingEdge[edge.idx()]:
if self.options.separateGluePairsByColor is True:
lineStyle.update({"stroke": randomColorSet[glueNumber[edge.idx()]]})
gluePairs += 1
lineStyle.update({"stroke-dashoffset":"0.0"})
lineStyle.update({"stroke-opacity":"1.0"})
if self.options.edgeStyle == "saturationsForAngles":
if dihedralAngle != 0: #we dont want to apply HSL adjustments for zero angle lines because they would be invisible then
hslColor = inkex.Color(lineStyle.get('stroke')).to_hsl()
newSaturation = abs(dihedralAngle / self.angleRange) * 100 #percentage values
hslColor.saturation = newSaturation
lineStyle.update({"stroke":hslColor.to_rgb()})
elif self.options.edgeStyle == "opacitiesForAngles":
if dihedralAngle != 0: #we dont want to apply opacity adjustments for zero angle lines because they would be invisible then
opacity = abs(dihedralAngle / 180)
lineStyle.update({"stroke-opacity": "{:0.6f}".format(opacity)})
line.style = lineStyle
#########################################################
# Textual things
#########################################################
halfEdge = mesh.halfedge_handle(edge, 0) # Find halfedge in the face
if mesh.face_handle(halfEdge).idx() == -1:
halfEdge = mesh.opposite_halfedge_handle(halfEdge)
vector = mesh.calc_edge_vector(halfEdge)
vector = vector / np.linalg.norm(vector) # normalize
midPoint = 0.5 * (
mesh.point(mesh.from_vertex_handle(halfEdge)) + mesh.point(mesh.to_vertex_handle(halfEdge)))
rotatedVector = np.array([-vector[1], vector[0], 0])
angle = np.arctan2(vector[1], vector[0])
position = midPoint + textDistance * rotatedVector
if self.options.flipLabels is True:
position = midPoint - textDistance * rotatedVector
rotation = 180 / np.pi * angle
if self.options.flipLabels is True:
rotation += 180
text = textEdgesGroup.add(TextElement(id=uniqueMainId + "-edgeNumber-" + str(edge.idx())))
text.set("x", "{:0.6f}".format(position[0]))
text.set("y", "{:0.6f}".format(position[1]))
text.set("font-size", "{:0.6f}".format(fontsize))
text.set("style", "stroke-width {:0.6f}".format(textStrokeWidth) + ";text-anchor:middle;text-align:center")
text.set("transform", "rotate({:0.6f} {:0.6f} {:0.6f})".format(rotation, position[0], position[1]))
tspan = text.add(Tspan())
tspan.set("x", "{:0.6f}".format(position[0]))
tspan.set("y", "{:0.6f}".format(position[1]))
tspan.set("style", "stroke-width {:0.6f}".format(textStrokeWidth) + ";text-anchor:middle;text-align:center")
tspanText = []
if self.options.printGluePairNumbers is True and not isFoldingEdge[edge.idx()]:
tspanText.append(str(glueNumber[edge.idx()]))
if self.options.printAngles is True and dihedralAngle != 0.0:
tspanText.append("{:0.2f}°".format(dihedralAngle))
if self.options.printLengths is True:
printUnit = True
if printUnit is False:
unitToPrint = self.svg.unit
else:
unitToPrint = ""
tspanText.append("{:0.2f} {}".format(self.options.scalefactor * math.hypot(vertex1[0] - vertex0[0], vertex1[1] - vertex0[1]), unitToPrint))
tspan.text = " | ".join(tspanText)
if tspan.text == "": #if no text we remove again to clean up
text.delete()
tspan.delete()
'''
merge cutting edges to single contour. code ripped off from "join path" extension
'''
if self.options.merge_cut_lines is True:
cutEdges = []
#find all cutting edges - they have to be sorted to build up a clean continuous line
for edge in edgesGroup:
edge_id = edge.get('id')
if "cut-edge-" in edge_id:
cutEdges.append(edge)
#find the cutting edge which starts at the previous cutting edge end point
paths = {p.get('id'): self.getPartsFromCubicSuper(CubicSuperPath(p.get('d'))) for p in cutEdges }
pathIds = [p.get('id') for p in cutEdges]
startPathId = pathIds[0]
pathIds = self.getArrangedIds(paths, startPathId)
newParts = []
firstElem = None
for key in pathIds:
parts = paths[key]
# ~ parts = getPartsFromCubicSuper(cspath)
start = parts[0][0][0]
elem = self.svg.getElementById(key)
if(len(newParts) == 0):
newParts += parts[:]
firstElem = elem
else:
if(self.vectCmpWithMargin(start, newParts[-1][-1][-1], margin = .01)):
newParts[-1] += parts[0]
else:
newSeg = [newParts[-1][-1][-1], newParts[-1][-1][-1], start, start]
newParts[-1].append(newSeg)
newParts[-1] += parts[0]
if(len(parts) > 1):
newParts += parts[1:]
parent = elem.getparent()
parent.remove(elem)
newElem = copy.copy(firstElem)
oldId = firstElem.get('id')
newElem.set('d', CubicSuperPath(self.getCubicSuperFromParts(newParts)))
newElem.set('id', oldId + '_joined')
parent.append(newElem) #insert at the end
if len(textFacesGroup) == 0:
textFacesGroup.delete() #delete if empty set
if len(textEdgesGroup) == 0:
textEdgesGroup.delete() #delete if empty set
if len(textGroup) == 0:
textGroup.delete() #delete if empty set
if self.options.printStats is True:
inkex.utils.debug(" * Number of cuts: " + str(cuts))
inkex.utils.debug(" * Number of coplanar edges: " + str(coplanarEdges))
inkex.utils.debug(" * Number of mountain folds: " + str(mountainFolds))
inkex.utils.debug(" * Number of valley folds: " + str(valleyFolds))
inkex.utils.debug(" * Number of glue pairs: {:0.0f}".format(gluePairs / 2))
inkex.utils.debug(" * min angle: {:0.2f}".format(self.minAngle))
inkex.utils.debug(" * max angle: {:0.2f}".format(self.maxAngle))
inkex.utils.debug(" * Edge angle range: {:0.2f}".format(self.angleRange))
return paperfoldPageGroup
def floatCmpWithMargin(self, float1, float2, margin):
return abs(float1 - float2) < margin
def vectCmpWithMargin(self, vect1, vect2, margin):
return all(self.floatCmpWithMargin(vect2[i], vect1[i], margin) for i in range(0, len(vect1)))
def getPartsFromCubicSuper(self, cspath):
parts = []
for subpath in cspath:
part = []
prevBezPt = None
for i, bezierPt in enumerate(subpath):
if(prevBezPt != None):
seg = [prevBezPt[1], prevBezPt[2], bezierPt[0], bezierPt[1]]
part.append(seg)
prevBezPt = bezierPt
parts.append(part)
return parts
def getCubicSuperFromParts(self, parts):
cbsuper = []
for part in parts:
subpath = []
lastPt = None
pt = None
for seg in part:
if(pt == None):
ptLeft = seg[0]
pt = seg[0]
ptRight = seg[1]
subpath.append([ptLeft, pt, ptRight])
ptLeft = seg[2]
pt = seg[3]
subpath.append([ptLeft, pt, pt])
cbsuper.append(subpath)
return cbsuper
def getArrangedIds(self, pathMap, startPathId):
nextPathId = startPathId
orderPathIds = [nextPathId]
#Arrange in order
while(len(orderPathIds) < len(pathMap)):
minDist = 9e+100 #A large float
closestId = None
np = pathMap[nextPathId]
npPts = [np[-1][-1][-1]]
if(len(orderPathIds) == 1):#compare both the ends for the first path
npPts.append(np[0][0][0])
for key in pathMap:
if(key in orderPathIds):
continue
parts = pathMap[key]
start = parts[0][0][0]
end = parts[-1][-1][-1]
for i, npPt in enumerate(npPts):
dist = abs(start[0] - npPt[0]) + abs(start[1] - npPt[1])
if(dist < minDist):
minDist = dist
closestId = key
dist = abs(end[0] - npPt[0]) + abs(end[1] - npPt[1])
if(dist < minDist):
minDist = dist
pathMap[key] = [[[pts for pts in reversed(seg)] for seg in \
reversed(part)] for part in reversed(parts)]
closestId = key
#If start point of the first path is closer reverse its direction
if(i > 0 and closestId == key):
pathMap[nextPathId] = [[[pts for pts in reversed(seg)] for seg in \
reversed(part)] for part in reversed(np)]
orderPathIds.append(closestId)
nextPathId = closestId
return orderPathIds
def add_arguments(self, pars):
pars.add_argument("--tab")
#Input
pars.add_argument("--inputfile")
pars.add_argument("--maxNumFaces", type=int, default=200, help="If the STL file has too much detail it contains a large number of faces. This will make unfolding extremely slow. So we can limit it.")
pars.add_argument("--scalefactor", type=float, default=1.0, help="Manual scale factor")
pars.add_argument("--roundingDigits", type=int, default=3, help="Digits for rounding")
#Output
pars.add_argument("--printGluePairNumbers", type=inkex.Boolean, default=False, help="Print glue pair numbers on cut edges")
pars.add_argument("--printAngles", type=inkex.Boolean, default=False, help="Print folding angles on edges")
pars.add_argument("--printLengths", type=inkex.Boolean, default=False, help="Print lengths on edges")
pars.add_argument("--printTriangleNumbers", type=inkex.Boolean, default=False, help="Print triangle numbers on faces")
pars.add_argument("--importCoplanarEdges", type=inkex.Boolean, default=False, help="Import coplanar edges")
pars.add_argument("--experimentalWeights", type=inkex.Boolean, default=False, help="Mess around with algorithm")
pars.add_argument("--printStats", type=inkex.Boolean, default=False, help="Show some unfold statistics")
pars.add_argument("--resizetoimport", type=inkex.Boolean, default=True, help="Resize the canvas to the imported drawing's bounding box")
pars.add_argument("--extraborder", type=float, default=0.0)
pars.add_argument("--extraborderUnits")
pars.add_argument("--writeTwoDSTL", type=inkex.Boolean, default=False, help="Write 2D STL unfoldings")
pars.add_argument("--TwoDSTLdir", default="./inkscape_export/", help="Location to save exported 2D STL")
#Style
pars.add_argument("--fontSize", type=int, default=15, help="Label font size (%)")
pars.add_argument("--flipLabels", type=inkex.Boolean, default=False, help="Flip labels")
pars.add_argument("--dashes", type=inkex.Boolean, default=True, help="Dashes for cut/coplanar edges")
pars.add_argument("--merge_cut_lines", type=inkex.Boolean, default=True, help="Merge cut lines")
pars.add_argument("--edgeStyle", help="Adjust color saturation or opacity for folding edges. The larger the angle the darker the color")
pars.add_argument("--separateGluePairsByColor", type=inkex.Boolean, default=False, help="Separate glue pairs by color")
pars.add_argument("--colorCutEdges", type=Color, default='255', help="Cut edges")
pars.add_argument("--colorCoplanarEdges", type=Color, default='1943148287', help="Coplanar edges")
pars.add_argument("--colorValleyFolds", type=Color, default='3422552319', help="Valley fold edges")
pars.add_argument("--colorMountainFolds", type=Color, default='879076607', help="Mountain fold edges")
#Post Processing
pars.add_argument("--joineryMode", type=inkex.Boolean, default=False, help="Enable joinery mode")
pars.add_argument("--origamiSimulatorMode", type=inkex.Boolean, default=False, help="Enable origami simulator mode")
def effect(self):
if not os.path.exists(self.options.inputfile):
inkex.utils.debug("The input file does not exist. Please select a proper file and try again.")
exit(1)
mesh = om.read_trimesh(self.options.inputfile)
#mesh = om.read_polymesh(self.options.inputfile) #we must work with triangles instead of polygons because the algorithm works with that ONLY
fullUnfolded, unfoldedComponents = self.unfold(mesh)
unfoldComponentCount = len(unfoldedComponents)
#if len(unfoldedComponents) == 0:
# inkex.utils.debug("Error: no components were unfolded.")
# exit(1)
if self.options.printStats is True:
inkex.utils.debug("Unfolding components: {:0.0f}".format(unfoldComponentCount))
# Compute maxSize of the components
# All components must be scaled to the same size as the largest component
maxSize = 0
for unfolding in unfoldedComponents:
[xmin, ymin, boxSize] = self.findBoundingBox(unfolding[0])
if boxSize > maxSize:
maxSize = boxSize
xSpacing = maxSize / unfoldComponentCount * 0.1 # 10% spacing between each component; calculated by max box size
#########################################################
# mode config for joinery:
#########################################################
if self.options.joineryMode is True:
self.options.separateGluePairsByColor = True #we need random colors in this mode
#########################################################
# mode config for origami simulator:
#########################################################
'''
required style for Origami Simulator:
colors:
- #ff0000 (red) - mountain folds
- #0000ff (blue) - valley folds
- #000000 (black) - boundary cuts (for both the outline of the pattern and any internal holes)
- #ffff00 (yellow) - coplonar triangle edges ("facet creases") (no support for polygons > 3 edges)
- #00ff00 (green) - thin slits
- #ff00ff (magenta) - undriven creases (swing freely)
opacity:
- final fold angle of a mountain or valley fold is set by its opacity. Any fold angle between 0° and 180° may be used. For example:
- 1.0 = 180° (fully folded)
- 0.5 = 90°
- 0 = 0° (flat)
'''
if self.options.origamiSimulatorMode is True:
self.options.joineryMode = True #we set to true even if false because we need the same flat structure for origami simulator
self.options.separateGluePairsByColor = False #we need to have no weird random colors in this mode
self.options.edgeStyle = "opacitiesForAngles" #highly important for simulation
self.options.dashes = False
self.options.printGluePairNumbers = False
self.options.printAngles = False
self.options.printLengths = False
self.options.importCoplanarEdges = True
self.options.colorCutEdges = "#000000" #black
self.options.colorCoplanarEdges = "#ffff00" #yellow
self.options.colorMountainFolds = "#ff0000" #red
self.options.colorValleyFolds = "#0000ff" #blue
#generate random colors; used to identify glue tab pairs
randomColorSet = []
if self.options.separateGluePairsByColor:
while len(randomColorSet) < len(mesh.edges()):
r = lambda: random.randint(0,255)
newColor = '#%02X%02X%02X' % (r(),r(),r())
if newColor not in randomColorSet:
randomColorSet.append(newColor)
# Create a new container group to attach all paperfolds
paperfoldMainGroup = self.document.getroot().add(inkex.Group(id=self.svg.get_unique_id("paperfold-"))) #make a new group at root level
for i in range(len(unfoldedComponents)):
if self.options.printStats is True:
inkex.utils.debug("-----------------------------------------------------------")
inkex.utils.debug("Unfolding component nr.: {:0.0f}".format(i))
paperfoldPageGroup = self.writeSVG(unfoldedComponents[i], maxSize, randomColorSet)
#translate the groups next to each other to remove overlappings
if i != 0:
previous_bbox = paperfoldMainGroup[i-1].bounding_box()
this_bbox = paperfoldPageGroup.bounding_box()
paperfoldPageGroup.set("transform", "translate({:0.6f}, 0.0)".format(previous_bbox.left + previous_bbox.width - this_bbox.left + xSpacing))
paperfoldMainGroup.append(paperfoldPageGroup)
#apply scale factor
translation_matrix = [[self.options.scalefactor, 0.0, 0.0], [0.0, self.options.scalefactor, 0.0]]
paperfoldMainGroup.transform = Transform(translation_matrix) * paperfoldMainGroup.transform
#paperfoldMainGroup.set('transform', 'scale(%f,%f)' % (self.options.scalefactor, self.options.scalefactor))
#adjust canvas to the inserted unfolding
if self.options.resizetoimport:
bbox = paperfoldMainGroup.bounding_box()
namedView = self.document.getroot().find(inkex.addNS('namedview', 'sodipodi'))
root = self.svg.getElement('//svg:svg');
offset = self.svg.unittouu(str(self.options.extraborder) + self.options.extraborderUnits)
root.set('viewBox', '%f %f %f %f' % (bbox.left - offset, bbox.top - offset, bbox.width + 2 * offset, bbox.height + 2 * offset))
root.set('width', "{:0.6f}{}".format(bbox.width + 2 * offset, self.svg.unit))
root.set('height', "{:0.6f}{}".format(bbox.height + 2 * offset, self.svg.unit))
#if set, we move all edges (path elements) to the top level
if self.options.joineryMode is True:
for paperfoldPage in paperfoldMainGroup.getchildren():
for child in paperfoldPage:
if "-edges" in child.get('id'):
for edge in child:
edgeTransform = edge.composed_transform()
self.document.getroot().append(edge)
edge.transform = edgeTransform
if __name__ == '__main__':
Paperfold().run()