Skip to content

Instantly share code, notes, and snippets.

@zeffii zeffii/
Last active Dec 17, 2015

What would you like to do?
intersect_all as an addon. seems ok! needs user testing
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
bl_info = {
"name": "Edge tools : tinyCAD X ALL",
"author": "zeffii",
"version": (0, 0, 4),
"blender": (2, 6, 7),
"category": "Mesh",
"location": "View3D > EditMode > (w) Specials",
"warning": "Still under development",
"wiki_url": "",
"tracker_url": ""
import bpy
import bmesh
from mathutils import Vector
from mathutils.geometry import intersect_line_line as LineIntersect
import itertools
from collections import defaultdict
VTX_PRECISION = 1.0e-5 # Epsilon. or 1.0e-6 ..if you need
''' helpers '''
def mDist(A, B):
''' returns distance between two given points '''
return (A-B).length
def isPointOnEdge(point, A, B):
''' returns True / False if a point happens to lie on an edge '''
eps = ((mDist(A, B) - mDist(point,B)) - mDist(A,point))
if abs(eps) < VTX_PRECISION: return True
return False
def CountPointOnEdges(point, edges):
''' returns the number of edges that a point lies on. '''
v1, v2, v3, v4 = edges
count = 0
if(isPointOnEdge(point, v1, v2)): count+=1
if(isPointOnEdge(point, v3, v4)): count+=1
return count
def vertex_indices_from_edges_tuple(bm, edge):
''' find the vertex indices of a 2-tuple of edges '''
k = lambda v, w: bm.edges[edge[v]].verts[w].index
return [k(i>>1, i%2)for i in range(4)]
def vector_from_indices(bm, raw_vert_indices):
return [bm.verts[i].co for i in raw_vert_indices]
def order_points(edge, point_list):
''' order these edges from distance to v1, then
sandwich the sorted list with v1, v2 '''
v1, v2 = edge
dist = lambda co: (v1-co).length
point_list = sorted(point_list, key=dist)
return [v1] + point_list + [v2]
def has_shared_vertex(vert_indices):
if len(set(vert_indices)) < len(vert_indices):
return True
def remove_permutations_that_share_a_vertex(bm, permutations):
''' Get useful Permutations '''
final_permutations = []
for edges in permutations:
raw_vert_indices = vertex_indices_from_edges_tuple(bm, edges)
if has_shared_vertex(raw_vert_indices): continue
# reaches this point if they do not share.
return final_permutations
def get_valid_permutations(bm, edge_indices):
raw_permutations = itertools.permutations(edge_indices, 2)
permutations = [result for result in raw_permutations if result[0] < result[1]]
return remove_permutations_that_share_a_vertex(bm, permutations)
def can_skip(closest_points, vert_vectors):
'''this checks if the intersection lies on both edges, returns True
when criteria are not met, and thus this point can be skipped'''
if not closest_points: return True
if not isinstance(closest_points[0].x, float): return True
if CountPointOnEdges(closest_points[0], vert_vectors) < 2: return True
# if this distance is larger than than VTX_PRECISION, we can skip it.
if mDist(closest_points[0], closest_points[1]) > VTX_PRECISION: return True
return False
def get_intersection_dictionary(bm, edge_indices):
permutations = get_valid_permutations(bm, edge_indices)
k = defaultdict(list)
d = defaultdict(list)
for edges in permutations:
raw_vert_indices = vertex_indices_from_edges_tuple(bm, edges)
vert_vectors = vector_from_indices(bm, raw_vert_indices)
points = LineIntersect(*vert_vectors)
# some can be skipped. (NaN, None, not on both edges)
if can_skip(points, vert_vectors): continue
# reaches this point only when an intersection happens on both edges.
[k[edge].append(points[0]) for edge in edges]
# k will contain a dict of edge indices and points found on those edges.
for edge_idx, unordered_points in k.items():
tv1, tv2 = bm.edges[edge_idx].verts
v1 = bm.verts[tv1.index].co
v2 = bm.verts[tv2.index].co
ordered_points = order_points((v1,v2), unordered_points)
return d
def update_mesh(obj, d):
''' Make new geometry (delete old first) '''
oe =
ov =
vert_count = len(ov)
edge_count = len(oe)
for old_edge, point_list in d.items():
num_points = len(point_list)
num_edges_to_add = num_points-1
for i in range(num_edges_to_add):
ov[vert_count].co = point_list[i]
ov[vert_count+1].co = point_list[i+1]
oe[edge_count].vertices = [vert_count, vert_count+1]
vert_count = len(ov)
edge_count = len(oe)
# set edit mode
bpy.ops.mesh.remove_doubles(threshold=VTX_DOUBLES_THRSHLD, use_unselected=False)
def unselect_nonintersecting(bm, d_edges, edge_indices):
if len(edge_indices) > len(d_edges):
reserved_edges = set(edge_indices) - set(d_edges)
for edge in reserved_edges:
bm.edges[edge].select = False
print("unselected {}, non intersecting edges".format(reserved_edges))
class IntersectAllEdges(bpy.types.Operator):
bl_idname = 'mesh.intersectall'
bl_label = 'Edge tools : tinyCAD X ALL'
# bl_options = {'REGISTER', 'UNDO'}
def poll(self, context):
obj = context.active_object
return obj != None and obj.type == 'MESH' and obj.mode == 'EDIT'
def execute(self, context):
# must force edge selection mode here
bpy.context.tool_settings.mesh_select_mode = (False, True, False)
obj = context.active_object
if obj.mode == "EDIT":
bm = bmesh.from_edit_mesh(
selected_edges = [edge for edge in bm.edges if]
edge_indices = [i.index for i in selected_edges]
d = get_intersection_dictionary(bm, edge_indices)
unselect_nonintersecting(bm, d.keys(), edge_indices)
update_mesh(obj, d)
print('must be in edit mode')
return {'FINISHED'}
def menu_func(self, context):
self.layout.operator(IntersectAllEdges.bl_idname, text="Intersect selected edges")
def register():
def unregister():
if __name__ == "__main__":
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.