If I have triangle fan that makes a circle, for example what you get when you Add->Circle, with fill type Triangle Fan, and I want to add more edge loops radially, what's the best way to do that?
I can sort of do this if I extrude the outer edge, then scale down the 'old' outer edge. Once I do this I can do loop cut like normal between the two but this modifies the original edge. I'd like to figure out a way to do this that doesn't touch the outer edges.
To add edge loops on a triangle fan, select all the faces of your circle, hit I button, adjust the distance of the loop with the mouse and repeat the operation with Shift+R until you have the number of loop cuts you want.
The easy way is use the cut faces addon from STANISLAV BLINOV:
general forum
how to use in circle:
video about how to use in circle
addon:
bl_info = {
"name" : "Cut Faces",
"author" : "Stanislav Blinov",
"version" : (1, 0, 0),
"blender" : (2, 72, 0),
"description" : "Cut Faces and Deselect Boundary operators",
"category" : "Mesh",}
import bpy
import bmesh
def bmesh_from_object(object):
mesh = object.data
if object.mode == 'EDIT':
bm = bmesh.from_edit_mesh(mesh)
else:
bm = bmesh.new()
bm.from_mesh(mesh)
return bm
def bmesh_release(bm, object):
mesh = object.data
bm.select_flush_mode()
if object.mode == 'EDIT':
bmesh.update_edit_mesh(mesh, True)
else:
bm.to_mesh(mesh)
bm.free()
def calc_face(face, keep_caps=True):
assert face.tag
def radial_loops(loop):
next = loop.link_loop_radial_next
while next != loop:
result, next = next, next.link_loop_radial_next
yield result
result = []
face.tag = False
selected = []
to_select = []
for loop in face.loops:
self_selected = False
# Iterate over selected adjacent faces
for radial_loop in filter(lambda l: l.face.select, radial_loops(loop)):
# Tag the edge if no other face done so already
if not loop.edge.tag:
loop.edge.tag = True
self_selected = True
adjacent_face = radial_loop.face
# Only walk adjacent face if current face tagged the edge
if adjacent_face.tag and self_selected:
result += calc_face(adjacent_face, keep_caps)
if loop.edge.tag:
(selected, to_select)[self_selected].append(loop)
for loop in to_select:
result.append(loop.edge)
selected.append(loop)
# Select opposite edge in quads
if keep_caps and len(selected) == 1 and len(face.verts) == 4:
result.append(selected[0].link_loop_next.link_loop_next.edge)
return result
def get_edge_rings(bm, keep_caps=True):
def tag_face(face):
if face.select:
face.tag = True
for edge in face.edges: edge.tag = False
return face.select
# fetch selected faces while setting up tags
selected_faces = [ f for f in bm.faces if tag_face(f) ]
edges = []
try:
# generate a list of edges to select:
# traversing only tagged faces, since calc_face can walk and untag islands
for face in filter(lambda f: f.tag, selected_faces): edges += calc_face(face, keep_caps)
finally:
# housekeeping: clear tags
for face in selected_faces:
face.tag = False
for edge in face.edges: edge.tag = False
return edges
class MESH_xOT_deselect_boundary(bpy.types.Operator):
"""Deselect boundary edges of selected faces"""
bl_idname = "mesh.ext_deselect_boundary"
bl_label = "Deselect Boundary"
bl_options = {'REGISTER', 'UNDO'}
keep_cap_edges = bpy.props.BoolProperty(
name = "Keep Cap Edges",
description = "Keep quad strip cap edges selected",
default = False)
@classmethod
def poll(cls, context):
active_object = context.active_object
return active_object and active_object.type == 'MESH' and active_object.mode == 'EDIT'
def execute(self, context):
object = context.active_object
bm = bmesh_from_object(object)
try:
edges = get_edge_rings(bm, keep_caps = self.keep_cap_edges)
if not edges:
self.report({'WARNING'}, "No suitable selection found")
return {'CANCELLED'}
bpy.ops.mesh.select_all(action='DESELECT')
bm.select_mode = {'EDGE'}
for edge in edges:
edge.select = True
context.tool_settings.mesh_select_mode[:] = False, True, False
finally:
bmesh_release(bm, object)
return {'FINISHED'}
class MESH_xOT_cut_faces(bpy.types.Operator):
"""Cut selected faces, connecting through their adjacent edges"""
bl_idname = "mesh.ext_cut_faces"
bl_label = "Cut Faces"
bl_options = {'REGISTER', 'UNDO'}
# from bmesh_operators.h
SUBD_INNERVERT = 0
SUBD_PATH = 1
SUBD_FAN = 2
SUBD_STRAIGHT_CUT = 3
num_cuts = bpy.props.IntProperty(
name = "Number of Cuts",
default = 1,
min = 1,
max = 100,
subtype = 'UNSIGNED')
use_single_edge = bpy.props.BoolProperty(
name = "Quad/Tri Mode",
description = "Cut boundary faces",
default = False)
corner_type = bpy.props.EnumProperty(
items = [('SUBD_INNERVERT', "Inner Vert", ""),
('SUBD_PATH', "Path", ""),
('SUBD_FAN', "Fan", ""),
('SUBD_STRAIGHT_CUT', "Straight Cut", ""),],
name = "Quad Corner Type",
description = "How to subdivide quad corners",
default = 'SUBD_STRAIGHT_CUT')
use_grid_fill = bpy.props.BoolProperty(
name = "Use Grid Fill",
description = "Fill fully enclosed faces with a grid",
default = True)
@classmethod
def poll(cls, context):
active_object = context.active_object
return active_object and active_object.type == 'MESH' and active_object.mode == 'EDIT'
def cut_edges(self, context):
object = context.active_object
bm = bmesh_from_object(object)
try:
edges = get_edge_rings(bm, keep_caps = True)
if not edges:
self.report({'WARNING'}, "No suitable selection found")
return False
result = bmesh.ops.subdivide_edges(
bm,
edges = edges,
cuts = int(self.num_cuts),
use_grid_fill = bool(self.use_grid_fill),
use_single_edge = bool(self.use_single_edge),
quad_corner_type = eval("self."+self.corner_type))
bpy.ops.mesh.select_all(action='DESELECT')
bm.select_mode = {'EDGE'}
inner = result['geom_inner']
for edge in filter(lambda e: isinstance(e, bmesh.types.BMEdge), inner):
edge.select = True
finally:
bmesh_release(bm, object)
return True
def execute(self, context):
if not self.cut_edges(context):
return {'CANCELLED'}
context.tool_settings.mesh_select_mode[:] = False, True, False
# Try to select all possible loops
bpy.ops.mesh.loop_multi_select(ring=False)
return {'FINISHED'}
def menu_deselect_boundary(self, context):
self.layout.operator(MESH_xOT_deselect_boundary.bl_idname)
def menu_cut_faces(self, context):
self.layout.operator(MESH_xOT_cut_faces.bl_idname)
def register():
bpy.utils.register_class(MESH_xOT_deselect_boundary)
bpy.utils.register_class(MESH_xOT_cut_faces)
if __name__ != "__main__":
bpy.types.VIEW3D_MT_select_edit_mesh.append(menu_deselect_boundary)
bpy.types.VIEW3D_MT_edit_mesh_faces.append(menu_cut_faces)
def unregister():
bpy.utils.unregister_class(MESH_xOT_deselect_boundary)
bpy.utils.unregister_class(MESH_xOT_cut_faces)
if __name__ != "__main__":
bpy.types.VIEW3D_MT_select_edit_mesh.remove(menu_deselect_boundary)
bpy.types.VIEW3D_MT_edit_mesh_faces.remove(menu_cut_faces)
if __name__ == "__main__":
register()
