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# ##### BEGIN GPL LICENSE BLOCK #####
#
# 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
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#
# ##### END GPL LICENSE BLOCK #####
# <pep8 compliant>
bl_info = {
"name": "Inset Straight Skeleton",
"author": "Howard Trickey",
"version": (1, 1),
"blender": (2, 80, 0),
"location": "3DView Operator",
"description": "Make an inset inside selection using straight skeleton algorithm.",
"warning": "",
"wiki_url": "https://docs.blender.org/manual/en/dev/addons/"
"mesh/inset_straight_skeleton.html",
"category": "Mesh"}
if "bpy" in locals():
import importlib
else:
from . import (
geom,
model,
offset,
triquad,
)
import math
import bpy
import bmesh
import mathutils
from mathutils import Vector
from bpy_extras import view3d_utils
import gpu
from gpu_extras.batch import batch_for_shader
from bpy.props import (
BoolProperty,
EnumProperty,
FloatProperty,
)
SpaceView3D = bpy.types.SpaceView3D
INSET_VALUE = 0
HEIGHT_VALUE = 1
NUM_VALUES = 2
# TODO: make a dooted-line shader
shader = gpu.shader.from_builtin('2D_UNIFORM_COLOR') if not bpy.app.background else None
class MESH_OT_InsetStraightSkeleton(bpy.types.Operator):
bl_idname = "mesh.insetstraightskeleton"
bl_label = "Inset Straight Skeleton"
bl_description = "Make an inset inside selection using straight skeleton algorithm"
bl_options = {'UNDO', 'REGISTER', 'GRAB_CURSOR', 'BLOCKING'}
inset_amount: FloatProperty(name="Amount",
description="Amount to move inset edges",
default=0.0,
min=0.0,
max=1000.0,
soft_min=0.0,
soft_max=100.0,
unit='LENGTH')
inset_height: FloatProperty(name="Height",
description="Amount to raise inset faces",
default=0.0,
min=-10000.0,
max=10000.0,
soft_min=-500.0,
soft_max=500.0,
unit='LENGTH')
region: BoolProperty(name="Region",
description="Inset selection as one region?",
default=True)
quadrangulate: BoolProperty(name="Quadrangulate",
description="Quadrangulate after inset?",
default=True)
@classmethod
def poll(cls, context):
obj = context.active_object
return (obj and obj.type == 'MESH' and context.mode == 'EDIT_MESH')
def draw(self, context):
layout = self.layout
box = layout.box()
box.label(text="Inset Options:")
box.prop(self, "inset_amount")
box.prop(self, "inset_height")
box.prop(self, "region")
box.prop(self, "quadrangulate")
def invoke(self, context, event):
self.modal = True
# make backup bmesh from current mesh, after flushing editmode to mesh
bpy.context.object.update_from_editmode()
self.backup = bmesh.new()
self.backup.from_mesh(bpy.context.object.data)
self.inset_amount = 0.0
self.inset_height = 0.0
self.center, self.center3d = calc_select_center(context)
self.center_pixel_size = calc_pixel_size(context, self.center3d)
udpi = context.preferences.system.dpi
upixelsize = context.preferences.system.pixel_size
self.pixels_per_inch = udpi * upixelsize
self.value_mode = INSET_VALUE
self.initial_length = [-1.0, -1.0]
self.scale = [self.center_pixel_size] * NUM_VALUES
self.calc_initial_length(event, True)
self.mouse_cur = Vector((event.mouse_region_x, event.mouse_region_y))
col = context.preferences.themes["Default"].view_3d.view_overlay
self.line_color = (col.r, col.g, col.b, 1.0)
self.action(context)
context.window_manager.modal_handler_add(self)
self.draw_handle = SpaceView3D.draw_handler_add(draw_callback,
(self,), 'WINDOW', 'POST_PIXEL')
return {'RUNNING_MODAL'}
def calc_initial_length(self, event, mode_changed):
mdiff = self.center - Vector((event.mouse_region_x, event.mouse_region_y))
mlen = mdiff.length;
vmode = self.value_mode
if mode_changed or self.initial_length[vmode] == -1:
if vmode == INSET_VALUE:
value = self.inset_amount
else:
value = self.inset_height
sc = self.scale[vmode]
if value != 0.0:
mlen = mlen - value / sc
self.initial_length[vmode] = mlen
def modal(self, context, event):
if event.type in ['LEFTMOUSE', 'RIGHTMOUSE', 'ESC']:
if self.modal:
self.backup.free()
if self.draw_handle:
SpaceView3D.draw_handler_remove(self.draw_handle, 'WINDOW')
context.area.tag_redraw()
if event.type == 'LEFTMOUSE': # Confirm
return {'FINISHED'}
else: # Cancel
return {'CANCELLED'}
else:
# restore mesh to original state
bpy.ops.object.editmode_toggle()
self.backup.to_mesh(bpy.context.object.data)
bpy.ops.object.editmode_toggle()
if event.type == 'MOUSEMOVE':
if self.value_mode == INSET_VALUE and event.ctrl:
self.value_mode = HEIGHT_VALUE
self.calc_initial_length(event, True)
elif self.value_mode == HEIGHT_VALUE and not event.ctrl:
self.value_mode = INSET_VALUE
self.calc_initial_length(event, True)
self.mouse_cur = Vector((event.mouse_region_x, event.mouse_region_y))
vmode = self.value_mode
mdiff = self.center - self.mouse_cur
value = (mdiff.length - self.initial_length[vmode]) * self.scale[vmode]
if vmode == INSET_VALUE:
self.inset_amount = value
else:
self.inset_height = value
elif event.type == 'R' and event.value == 'PRESS':
self.region = not self.region
elif event.type == 'Q' and event.value == 'PRESS':
self.quadrangulate = not self.quadrangulate
self.action(context)
return {'RUNNING_MODAL'}
def execute(self, context):
self.modal = False
self.action(context)
return {'FINISHED'}
def action(self, context):
obj = bpy.context.active_object
mesh = obj.data
do_inset(mesh, self.inset_amount, self.inset_height, self.region,
self.quadrangulate)
bpy.ops.object.editmode_toggle()
bpy.ops.object.editmode_toggle()
def draw_callback(op):
startpos = op.mouse_cur
endpos = op.center
coords = [startpos.to_tuple(), endpos.to_tuple()]
batch = batch_for_shader(shader, 'LINES', {"pos": coords})
try:
shader.bind()
shader.uniform_float("color", op.line_color)
batch.draw(shader)
except:
pass
def calc_pixel_size(context, co):
# returns size in blender units of a pixel at 3d coord co
# see C code in ED_view3d_pixel_size and ED_view3d_update_viewmat
m = context.region_data.perspective_matrix
v1 = m[0].to_3d()
v2 = m[1].to_3d()
ll = min(v1.length_squared, v2.length_squared)
len_pz = 2.0 / math.sqrt(ll)
len_sz = max(context.region.width, context.region.height)
rv3dpixsize = len_pz / len_sz
proj = m[3][0] * co[0] + m[3][1] * co[1] + m[3][2] * co[2] + m[3][3]
ups = context.preferences.system.pixel_size
return proj * rv3dpixsize * ups
def calc_select_center(context):
# returns region 2d coord and global 3d coord of selection center
ob = bpy.context.active_object
mesh = ob.data
center = Vector((0.0, 0.0, 0.0))
n = 0
for v in mesh.vertices:
if v.select:
center = center + Vector(v.co)
n += 1
if n > 0:
center = center / n
world_center = ob.matrix_world @ center
world_center_2d = view3d_utils.location_3d_to_region_2d( \
context.region, context.region_data, world_center)
return (world_center_2d, world_center)
def do_inset(mesh, amount, height, region, quadrangulate):
if amount <= 0.0:
return
pitch = math.atan(height / amount)
selfaces = []
selface_indices = []
bm = bmesh.from_edit_mesh(mesh)
for face in bm.faces:
if face.select:
selfaces.append(face)
selface_indices.append(face.index)
m = geom.Model()
# if add all mesh.vertices, coord indices will line up
# Note: not using Points.AddPoint which does dup elim
# because then would have to map vertices in and out
m.points.pos = [v.co.to_tuple() for v in bm.verts]
for f in selfaces:
m.faces.append([loop.vert.index for loop in f.loops])
m.face_data.append(f.index)
orig_numv = len(m.points.pos)
orig_numf = len(m.faces)
model.BevelSelectionInModel(m, amount, pitch, quadrangulate, region, False)
if len(m.faces) == orig_numf:
# something went wrong with Bevel - just treat as no-op
return
blender_faces = m.faces[orig_numf:len(m.faces)]
blender_old_face_index = m.face_data[orig_numf:len(m.faces)]
for i in range(orig_numv, len(m.points.pos)):
bvertnew = bm.verts.new(m.points.pos[i])
bm.verts.index_update()
bm.verts.ensure_lookup_table()
new_faces = []
start_faces = len(bm.faces)
for i, newf in enumerate(blender_faces):
vs = remove_dups([bm.verts[j] for j in newf])
if len(vs) < 3:
continue
# copy face attributes from old face that it was derived from
bfi = blender_old_face_index[i]
# sometimes, not sure why, this face already exists
# bmesh will give a value error in bm.faces.new() in that case
try:
if bfi and 0 <= bfi < start_faces:
bm.faces.ensure_lookup_table()
oldface = bm.faces[bfi]
bfacenew = bm.faces.new(vs, oldface)
# bfacenew.copy_from_face_interp(oldface)
else:
bfacenew = bm.faces.new(vs)
new_faces.append(bfacenew)
except ValueError:
# print("dup face with amount", amount)
# print([v.index for v in vs])
pass
# deselect original faces
for face in selfaces:
face.select_set(False)
# remove original faces
bmesh.ops.delete(bm, geom=selfaces, context='FACES')
# select all new faces (should only select inner faces, but that needs more surgery on rest of code)
for face in new_faces:
face.select_set(True)
bmesh.update_edit_mesh(mesh)
def remove_dups(vs):
seen = set()
return [x for x in vs if not (x in seen or seen.add(x))]
def menu(self, context):
self.layout.operator("mesh.insetstraightskeleton", text="Inset Straight Skeleton")
def register():
bpy.utils.register_class(MESH_OT_InsetStraightSkeleton)
bpy.types.VIEW3D_MT_edit_mesh_faces.append(menu)
def unregister():
bpy.utils.unregister_class(MESH_OT_InsetStraightSkeleton)
bpy.types.VIEW3D_MT_edit_mesh_faces.remove(menu)
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