Campbell Barton
e8da6131fd
Move copyright text to SPDX-FileCopyrightText or set to the Blender Foundation so "make check_licenses" now runs without warnings.
560 lines
19 KiB
Python
560 lines
19 KiB
Python
# SPDX-FileCopyrightText: 2011-2022 Blender Foundation
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#
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# SPDX-License-Identifier: GPL-2.0-or-later
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"""Manipulations of Models.
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"""
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__author__ = "howard.trickey@gmail.com"
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from . import geom
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from . import triquad
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from . import offset
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import math
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def PolyAreasToModel(polyareas, bevel_amount, bevel_pitch, quadrangulate):
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"""Convert a PolyAreas into a Model object.
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Assumes polyareas are in xy plane.
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Args:
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polyareas: geom.PolyAreas
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bevel_amount: float - if > 0, amount of bevel
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bevel_pitch: float - if > 0, angle in radians of bevel
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quadrangulate: bool - should n-gons be quadrangulated?
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Returns:
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geom.Model
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"""
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m = geom.Model()
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if not polyareas:
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return m
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polyareas.points.AddZCoord(0.0)
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m.points = polyareas.points
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for pa in polyareas.polyareas:
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PolyAreaToModel(m, pa, bevel_amount, bevel_pitch, quadrangulate)
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return m
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def PolyAreaToModel(m, pa, bevel_amount, bevel_pitch, quadrangulate):
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if bevel_amount > 0.0:
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BevelPolyAreaInModel(m, pa, bevel_amount, bevel_pitch, quadrangulate,
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False)
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elif quadrangulate:
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if len(pa.poly) == 0:
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return
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qpa = triquad.QuadrangulateFaceWithHoles(pa.poly, pa.holes, pa.points)
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m.faces.extend(qpa)
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m.face_data.extend([pa.data] * len(qpa))
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else:
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m.faces.append(pa.poly)
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# TODO: just the first part of QuadrangulateFaceWithHoles, to join
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# holes to outer poly
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m.face_data.append(pa.data)
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def ExtrudePolyAreasInModel(mdl, polyareas, depth, cap_back):
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"""Extrude the boundaries given by polyareas by -depth in z.
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Assumes polyareas are in xy plane.
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Arguments:
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mdl: geom.Model - where to do extrusion
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polyareas: geom.Polyareas
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depth: float
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cap_back: bool - if True, cap off the back
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Side Effects:
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For all edges in polys in polyareas, make quads in Model
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extending those edges by depth in the negative z direction.
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The application data will be the data of the face that the edge
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is part of.
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"""
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for pa in polyareas.polyareas:
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back_poly = _ExtrudePoly(mdl, pa.poly, depth, pa.data, True)
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back_holes = []
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for p in pa.holes:
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back_holes.append(_ExtrudePoly(mdl, p, depth, pa.data, False))
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if cap_back:
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qpa = triquad.QuadrangulateFaceWithHoles(back_poly, back_holes,
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polyareas.points)
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# need to reverse each poly to get normals pointing down
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for i, p in enumerate(qpa):
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t = list(p)
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t.reverse()
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qpa[i] = tuple(t)
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mdl.faces.extend(qpa)
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mdl.face_data.extend([pa.data] * len(qpa))
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def _ExtrudePoly(mdl, poly, depth, data, isccw):
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"""Extrude the poly by -depth in z
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Arguments:
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mdl: geom.Model - where to do extrusion
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poly: list of vertex indices
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depth: float
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data: application data
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isccw: True if counter-clockwise
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Side Effects
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For all edges in poly, make quads in Model
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extending those edges by depth in the negative z direction.
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The application data will be the data of the face that the edge
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is part of.
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Returns:
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list of int - vertices for extruded poly
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"""
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if len(poly) < 2:
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return
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extruded_poly = []
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points = mdl.points
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if isccw:
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incr = 1
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else:
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incr = -1
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for i, v in enumerate(poly):
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vnext = poly[(i + incr) % len(poly)]
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(x0, y0, z0) = points.pos[v]
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(x1, y1, z1) = points.pos[vnext]
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vextrude = points.AddPoint((x0, y0, z0 - depth))
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vnextextrude = points.AddPoint((x1, y1, z1 - depth))
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if isccw:
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sideface = [v, vextrude, vnextextrude, vnext]
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else:
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sideface = [v, vnext, vnextextrude, vextrude]
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mdl.faces.append(sideface)
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mdl.face_data.append(data)
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extruded_poly.append(vextrude)
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return extruded_poly
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def BevelPolyAreaInModel(mdl, polyarea,
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bevel_amount, bevel_pitch, quadrangulate, as_percent):
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"""Bevel the interior of polyarea in model.
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This does smart beveling: advancing edges are merged
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rather than doing an 'overlap'. Advancing edges that
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hit an opposite edge result in a split into two beveled areas.
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If the polyarea is not in the xy plane, do the work in a
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transformed model, and then transfer the changes back.
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Arguments:
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mdl: geom.Model - where to do bevel
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polyarea geom.PolyArea - area to bevel into
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bevel_amount: float - if > 0, amount of bevel
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bevel_pitch: float - if > 0, angle in radians of bevel
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quadrangulate: bool - should n-gons be quadrangulated?
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as_percent: bool - if True, interpret amount as percent of max
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Side Effects:
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Faces and points are added to model to model the
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bevel and the interior of the polyareas.
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"""
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pa_norm = polyarea.Normal()
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if pa_norm == (0.0, 0.0, 1.0):
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m = mdl
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pa_rot = polyarea
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else:
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(pa_rot, inv_rot, inv_map) = _RotatedPolyAreaToXY(polyarea, pa_norm)
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# don't have to add the original faces into model, just their points.
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m = geom.Model()
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m.points = pa_rot.points
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vspeed = math.tan(bevel_pitch)
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off = offset.Offset(pa_rot, 0.0, vspeed)
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if as_percent:
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bevel_amount = bevel_amount * off.MaxAmount() / 100.0
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off.Build(bevel_amount)
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inner_pas = AddOffsetFacesToModel(m, off, polyarea.data)
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for pa in inner_pas.polyareas:
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if quadrangulate:
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if len(pa.poly) == 0:
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continue
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qpa = triquad.QuadrangulateFaceWithHoles(pa.poly, pa.holes,
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pa.points)
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m.faces.extend(qpa)
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m.face_data.extend([pa.data] * len(qpa))
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else:
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m.faces.append(pa.poly)
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m.face_data.append(pa.data)
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if m != mdl:
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_AddTransformedPolysToModel(mdl, m.faces, m.points, m.face_data,
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inv_rot, inv_map)
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def AddOffsetFacesToModel(mdl, off, data=None):
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"""Add the faces due to an offset into model.
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Returns the remaining interiors of the offset as a PolyAreas.
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Args:
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mdl: geom.Model - model to add offset faces into
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off: offset.Offset
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data: any - application data to be copied to the faces
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Returns:
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geom.PolyAreas
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"""
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mdl.points = off.polyarea.points
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assert(len(mdl.points.pos) == 0 or len(mdl.points.pos[0]) == 3)
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o = off
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ostack = []
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while o:
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if o.endtime != 0.0:
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for face in o.facespokes:
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n = len(face)
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for i, spoke in enumerate(face):
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nextspoke = face[(i + 1) % n]
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v0 = spoke.origin
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v1 = nextspoke.origin
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v2 = nextspoke.dest
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v3 = spoke.dest
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if v2 == v3:
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mface = [v0, v1, v2]
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else:
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mface = [v0, v1, v2, v3]
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mdl.faces.append(mface)
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mdl.face_data.append(data)
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ostack.extend(o.inneroffsets)
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if ostack:
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o = ostack.pop()
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else:
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o = None
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return off.InnerPolyAreas()
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def BevelSelectionInModel(mdl, bevel_amount, bevel_pitch, quadrangulate,
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as_region, as_percent):
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"""Bevel all the faces in the model, perhaps as one region.
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If as_region is False, each face is beveled individually,
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otherwise regions of contiguous faces are merged into
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PolyAreas and beveled as a whole.
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TODO: something if extracted PolyAreas are not approximately
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planar.
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Args:
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mdl: geom.Model
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bevel_amount: float - amount to inset
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bevel_pitch: float - angle of bevel side
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quadrangulate: bool - should insides be quadrangulated?
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as_region: bool - should faces be merged into regions?
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as_percent: bool - should amount be interpreted as a percent
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of the maximum amount (if True) or an absolute amount?
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Side effect:
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Beveling faces will be added to the model
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"""
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pas = []
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if as_region:
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pas = RegionToPolyAreas(mdl.faces, mdl.points, mdl.face_data)
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else:
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for f, face in enumerate(mdl.faces):
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pas.append(geom.PolyArea(mdl.points, face, [],
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mdl.face_data[f]))
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for pa in pas:
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BevelPolyAreaInModel(mdl, pa,
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bevel_amount, bevel_pitch, quadrangulate, as_percent)
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def RegionToPolyAreas(faces, points, data):
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"""Find polygonal outlines induced by union of faces.
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Finds the polygons formed by boundary edges (those not
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sharing an edge with another face in region_faces), and
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turns those into PolyAreas.
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In the general case, there will be holes inside.
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We want to associate data with the region PolyAreas.
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Just choose a representative element of data[] when
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more than one face is combined into a PolyArea.
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Args:
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faces: list of list of int - each sublist is a face (indices into points)
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points: geom.Points - gives coordinates for vertices
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data: list of any - parallel to faces, app data to put in PolyAreas
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Returns:
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list of geom.PolyArea
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"""
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ans = []
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(edges, vtoe) = _GetEdgeData(faces)
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(face_adj, is_interior_edge) = _GetFaceGraph(faces, edges, vtoe, points)
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(components, ftoc) = _FindFaceGraphComponents(faces, face_adj)
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for c in range(len(components)):
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boundary_edges = set()
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betodata = dict()
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vstobe = dict()
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for e, ((vs, ve), f) in enumerate(edges):
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if ftoc[f] != c or is_interior_edge[e]:
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continue
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boundary_edges.add(e)
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# vstobe[v] is set of edges leaving v
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# (could be more than one if boundary touches itself at a vertex)
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if vs in vstobe:
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vstobe[vs].append(e)
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else:
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vstobe[vs] = [e]
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betodata[(vs, ve)] = data[f]
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polys = []
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poly_data = []
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while boundary_edges:
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e = boundary_edges.pop()
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((vstart, ve), face_i) = edges[e]
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poly = [vstart, ve]
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datum = betodata[(vstart, ve)]
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while ve != vstart:
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if ve not in vstobe:
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print("whoops, couldn't close boundary")
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break
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nextes = vstobe[ve]
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if len(nextes) == 1:
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nexte = nextes[0]
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else:
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# find a next edge with face index face_i
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# TODO: this is not guaranteed to work,
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# as continuation edge may have been for a different
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# face that is now combined with face_i by erasing
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# interior edges. Find a better algorithm here.
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nexte = -1
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for ne_cand in nextes:
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if edges[ne_cand][1] == face_i:
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nexte = ne_cand
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break
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if nexte == -1:
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# case mentioned in TODO may have happened;
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# just choose any nexte - may mess things up
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nexte = nextes[0]
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((_, ve), face_i) = edges[nexte]
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if nexte not in boundary_edges:
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print("whoops, nexte not a boundary edge", nexte)
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break
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boundary_edges.remove(nexte)
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if ve != vstart:
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poly.append(ve)
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polys.append(poly)
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poly_data.append(datum)
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if len(polys) == 0:
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# can happen if an entire closed polytope is given
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# at least until we do an edge check
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return []
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elif len(polys) == 1:
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ans.append(geom.PolyArea(points, polys[0], [], poly_data[0]))
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else:
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outerf = _FindOuterPoly(polys, points, faces)
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pa = geom.PolyArea(points, polys[outerf], [], poly_data[outerf])
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pa.holes = [polys[i] for i in range(len(polys)) if i != outerf]
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ans.append(pa)
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return ans
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def _GetEdgeData(faces):
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"""Find edges from faces, and some lookup dictionaries.
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Args:
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faces: list of list of int - each a closed CCW polygon of vertex indices
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Returns:
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(list of ((int, int), int), dict{ int->list of int}) -
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list elements are ((startv, endv), face index)
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dict maps vertices to edge indices
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"""
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edges = []
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vtoe = dict()
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for findex, f in enumerate(faces):
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nf = len(f)
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for i, v in enumerate(f):
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endv = f[(i + 1) % nf]
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edges.append(((v, endv), findex))
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eindex = len(edges) - 1
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if v in vtoe:
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vtoe[v].append(eindex)
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else:
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vtoe[v] = [eindex]
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return (edges, vtoe)
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def _GetFaceGraph(faces, edges, vtoe, points):
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"""Find the face adjacency graph.
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Faces are adjacent if they share an edge,
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and the shared edge goes in the reverse direction,
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and if the angle between them isn't too large.
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Args:
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faces: list of list of int
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edges: list of ((int, int), int) - see _GetEdgeData
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vtoe: dict{ int->list of int } - see _GetEdgeData
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points: geom.Points
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Returns:
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(list of list of int, list of bool) -
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first list: each sublist is adjacent face indices for each face
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second list: maps edge index to True if it separates adjacent faces
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"""
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face_adj = [[] for i in range(len(faces))]
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is_interior_edge = [False] * len(edges)
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for e, ((vs, ve), f) in enumerate(edges):
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for other in vtoe[ve]:
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((_, we), g) = edges[other]
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if we == vs:
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# face g is adjacent to face f
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# TODO: angle check
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if g not in face_adj[f]:
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face_adj[f].append(g)
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is_interior_edge[e] = True
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# Don't bother with mirror relations, will catch later
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return (face_adj, is_interior_edge)
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def _FindFaceGraphComponents(faces, face_adj):
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"""Partition faces into connected components.
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Args:
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faces: list of list of int
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face_adj: list of list of int - see _GetFaceGraph
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Returns:
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(list of list of int, list of int) -
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first list partitions face indices into separate lists,
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each a component
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second list maps face indices into their component index
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"""
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if not faces:
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return ([], [])
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components = []
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ftoc = [-1] * len(faces)
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for i in range(len(faces)):
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if ftoc[i] == -1:
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compi = len(components)
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comp = []
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_FFGCSearch(i, faces, face_adj, ftoc, compi, comp)
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components.append(comp)
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return (components, ftoc)
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def _FFGCSearch(findex, faces, face_adj, ftoc, compi, comp):
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"""Depth first search helper function for _FindFaceGraphComponents
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Searches recursively through all faces connected to findex, adding
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each face found to comp and setting ftoc for that face to compi.
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"""
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comp.append(findex)
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ftoc[findex] = compi
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for otherf in face_adj[findex]:
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if ftoc[otherf] == -1:
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_FFGCSearch(otherf, faces, face_adj, ftoc, compi, comp)
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def _FindOuterPoly(polys, points, faces):
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"""Assuming polys has one CCW-oriented face when looking
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down average normal of faces, return that one.
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Only one of the faces should have a normal whose dot product
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with the average normal of faces is positive.
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Args:
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polys: list of list of int - list of polys given by vertex indices
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points: geom.Points
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faces: list of list of int - original selected region, used to find
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average normal
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Returns:
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int - the index in polys of the outermost one
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"""
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if len(polys) < 2:
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return 0
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fnorm = (0.0, 0.0, 0.0)
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for face in faces:
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if len(face) > 2:
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fnorm = geom.VecAdd(fnorm, geom.Newell(face, points))
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if fnorm == (0.0, 0.0, 0.0):
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return 0
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# fnorm is really a multiple of the normal, but fine for test below
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for i, poly in enumerate(polys):
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if len(poly) > 2:
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pnorm = geom.Newell(poly, points)
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if geom.VecDot(fnorm, pnorm) > 0:
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return i
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print("whoops, couldn't find an outermost poly")
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return 0
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def _RotatedPolyAreaToXY(polyarea, norm):
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"""Return a PolyArea rotated to xy plane.
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Only the points in polyarea will be transferred.
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Args:
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polyarea: geom.PolyArea
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norm: the normal for polyarea
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Returns:
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(geom.PolyArea, (float, ..., float), dict{ int -> int }) - new PolyArea,
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4x3 inverse transform, dict mapping new verts to old ones
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"""
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# find rotation matrix that takes norm to (0,0,1)
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(nx, ny, nz) = norm
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if abs(nx) < abs(ny) and abs(nx) < abs(nz):
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v = (vx, vy, vz) = geom.Norm3(0.0, nz, - ny)
|
|
elif abs(ny) < abs(nz):
|
|
v = (vx, vy, vz) = geom.Norm3(nz, 0.0, - nx)
|
|
else:
|
|
v = (vx, vy, vz) = geom.Norm3(ny, - nx, 0.0)
|
|
(ux, uy, uz) = geom.Cross3(v, norm)
|
|
rotmat = [ux, vx, nx, uy, vy, ny, uz, vz, nz, 0.0, 0.0, 0.0]
|
|
# rotation matrices are orthogonal, so inverse is transpose
|
|
invrotmat = [ux, uy, uz, vx, vy, vz, nx, ny, nz, 0.0, 0.0, 0.0]
|
|
pointmap = dict()
|
|
invpointmap = dict()
|
|
newpoints = geom.Points()
|
|
for poly in [polyarea.poly] + polyarea.holes:
|
|
for v in poly:
|
|
vcoords = polyarea.points.pos[v]
|
|
newvcoords = geom.MulPoint3(vcoords, rotmat)
|
|
newv = newpoints.AddPoint(newvcoords)
|
|
pointmap[v] = newv
|
|
invpointmap[newv] = v
|
|
pa = geom.PolyArea(newpoints)
|
|
pa.poly = [pointmap[v] for v in polyarea.poly]
|
|
pa.holes = [[pointmap[v] for v in hole] for hole in polyarea.holes]
|
|
pa.data = polyarea.data
|
|
return (pa, invrotmat, invpointmap)
|
|
|
|
|
|
def _AddTransformedPolysToModel(mdl, polys, points, poly_data,
|
|
transform, pointmap):
|
|
"""Add (transformed) the points and faces to a model.
|
|
|
|
Add polys to mdl. The polys have coordinates given by indices
|
|
into points.pos; those need to be transformed by multiplying by
|
|
the transform matrix.
|
|
The vertices may already exist in mdl. Rather than relying on
|
|
AddPoint to detect the duplicate (transform rounding error makes
|
|
that dicey), the pointmap dictionar is used to map vertex indices
|
|
in polys into those in mdl - if they exist already.
|
|
|
|
Args:
|
|
mdl: geom.Model - where to put new vertices, faces
|
|
polys: list of list of int - each sublist a poly
|
|
points: geom.Points - coords for vertices in polys
|
|
poly_data: list of any - parallel to polys
|
|
transform: (float, ..., float) - 12-tuple, a 4x3 transform matrix
|
|
pointmap: dict { int -> int } - maps new vertex indices to old ones
|
|
Side Effects:
|
|
The model gets new faces and vertices, based on those in polys.
|
|
We are allowed to modify pointmap, as it will be discarded after call.
|
|
"""
|
|
|
|
for i, coords in enumerate(points.pos):
|
|
if i not in pointmap:
|
|
p = geom.MulPoint3(coords, transform)
|
|
pointmap[i] = mdl.points.AddPoint(p)
|
|
for i, poly in enumerate(polys):
|
|
mpoly = [pointmap[v] for v in poly]
|
|
mdl.faces.append(mpoly)
|
|
mdl.face_data.append(poly_data[i])
|