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985c397 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 | # SPDX-License-Identifier: LGPL-2.1-or-later
# ***************************************************************************
# * Copyright (c) 2021 sliptonic <shopinthewoods@gmail.com> *
# * *
# * This program is free software; you can redistribute it and/or modify *
# * it under the terms of the GNU Lesser General Public License (LGPL) *
# * as published by the Free Software Foundation; either version 2 of *
# * the License, or (at your option) any later version. *
# * for detail see the LICENCE text file. *
# * *
# * 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 Library General Public License for more details. *
# * *
# * You should have received a copy of the GNU Library 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 *
# * *
# ***************************************************************************
# Technical Debt. This generator currently assumes 3+2 axis rotation of CA.
# The main generator function should be extended to include other flavors of 3+2
import math
import Path
import FreeCAD
from enum import Enum
__title__ = "Rotation toolpath Generator"
__author__ = "sliptonic (Brad Collette)"
__url__ = "https://www.freecad.org"
__doc__ = "Generates the rotation toolpath"
if False:
Path.Log.setLevel(Path.Log.Level.DEBUG, Path.Log.thisModule())
Path.Log.trackModule(Path.Log.thisModule())
else:
Path.Log.setLevel(Path.Log.Level.INFO, Path.Log.thisModule())
class refAxis(Enum):
x = FreeCAD.Vector(1, 0, 0)
y = FreeCAD.Vector(0, 1, 0)
z = FreeCAD.Vector(0, 0, 1)
def relAngle(vec, ref):
"""
Takes a vector and a reference axis (refAxis) vector. Calculates the
relative angle. The result is returned in degrees (plus or minus)
"""
Path.Log.debug("vec: {} ref: {}".format(vec, ref))
norm = vec * 1 # copy vec so we don't alter original
if ref == refAxis.x:
plane = refAxis.y.value
elif ref == refAxis.y:
plane = refAxis.z.value
else:
plane = refAxis.x.value
norm.projectToPlane(FreeCAD.Vector(0, 0, 0), plane)
ref = ref.value
rot = FreeCAD.Rotation(norm, ref)
ang = math.degrees(rot.Angle)
angle = ang * plane.dot(rot.Axis)
Path.Log.debug("relative ang: {}".format(angle))
return angle
def __getCRotation(normalVector, cMin=-360, cMax=360):
"""
Calculate the valid C axis rotations component to align the normalVector
with either the +y or -y axis.
multiple poses may be possible. Returns a list of all valid poses
"""
Path.Log.debug("normalVector: {} cMin: {} cMax: {}".format(normalVector, cMin, cMax))
angle = relAngle(normalVector, refAxis.y)
# Given an angle, there are four possibilities; rotating +- to each of the
# two axes +y and -y
candidates = [angle]
if angle == 0:
candidates.append(180)
elif angle == 180:
candidates.append(0)
elif angle >= 0:
candidates.append(angle - 180)
candidates.append(180 + angle)
candidates.append(angle - 360)
else:
candidates.append(angle + 180)
candidates.append(-180 + angle)
candidates.append(angle + 360)
# final results are candidates that don't violate rotation limits
results = [c for c in candidates if c >= cMin and c <= cMax]
return results
def __getARotation(normalVector, aMin=-360, aMax=360):
"""
Calculate the A axis rotation component.
Final rotation is always assumed to be around +X. The sign of the returned
value indicates direction of rotation.
Returns None if rotation violates min/max constraints
"""
angle = relAngle(normalVector, refAxis.z)
# only return a result if it doesn't violate rotation constraints
if angle > aMin and angle <= aMax:
return angle
else:
return None
def generate(normalVector, aMin=-360, aMax=360, cMin=-360, cMax=360, compound=False):
"""
Generates Gcode rotation to align a vector (alignVector) with the positive Z axis.
It first rotates around the Z axis (C rotation)
to align the vector the positive Y axis. Then around the X axis
(A rotation).
The min and max arguments dictate the range of motion allowed rotation in
the respective axis.
Default assumes continuous rotation.
Returns a list of path commands for the shortest valid solution
If compound is False, axis moves will be broken out to individual commands
The normalVector input from a typical face (f) can be obtained like this:
u, v = f.ParameterRange[:2]
n = f.normalAt(u,v)
plm = obj.getGlobalPlacement()
rot = plm.Rotation
normalVector = rot.multVec(n
"""
Path.Log.track(
"\n=============\n normalVector: {}\n aMin: {}\n aMax: {}\n cMin: {}\n cMax: {}".format(
normalVector, aMin, aMax, cMin, cMax
)
)
# Calculate C rotation
cResults = __getCRotation(normalVector, cMin, cMax)
Path.Log.debug("C Rotation results {}".format(cResults))
solutions = []
for result in cResults:
# calculate a new vector based on the result
rot = FreeCAD.Rotation(FreeCAD.Vector(0, 0, 1), result)
newvec = rot.multVec(normalVector)
# Get the candidate A rotation for the new vector
aResult = __getARotation(newvec, aMin, aMax)
Path.Log.debug("\n=====\nFor C Rotation: {}\n Calculated A {}\n".format(result, aResult))
if aResult is not None:
solutions.append({"A": aResult, "C": result})
if len(solutions) == 0: # No valid solution found
raise ValueError("No valid rotation solution found")
# find pose with the shortest transit length
best = solutions[0]
curlen = math.fabs(best["A"]) + math.fabs(best["C"])
for solution in solutions[1:]:
testlen = math.fabs(solution["A"]) + math.fabs(solution["C"])
if testlen < curlen:
best = solution
curlen = testlen
Path.Log.debug("best result: {}".format(best))
# format and return rotation commands
commands = []
if compound:
commands.append(Path.Command("G0", best))
else:
for key, val in best.items():
print(key, val)
commands.append(Path.Command("G0", {key: val}))
return commands
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