# This PostProcessingPlugin script is released under the terms of the AGPLv3 or higher.
"""
Copyright (c) 2017 Christophe Baribaud 2017
Python implementation of https://github.com/electrocbd/post_stretch
Correction of hole sizes, cylinder diameters and curves
See the original description in https://github.com/electrocbd/post_stretch
WARNING This script has never been tested with several extruders
"""
from ..Script import Script
import numpy as np
from UM.Logger import Logger
import re
from cura.Settings.ExtruderManager import ExtruderManager
def _getValue(line, key, default=None):
"""
Convenience function that finds the value in a line of g-code.
When requesting key = x from line "G1 X100" the value 100 is returned.
It is a copy of Stript's method, so it is no DontRepeatYourself, but
I split the class into setup part (Stretch) and execution part (Strecher)
and only the setup part inherits from Script
"""
if not key in line or (";" in line and line.find(key) > line.find(";")):
return default
sub_part = line[line.find(key) + 1:]
number = re.search(r"^-?[0-9]+\.?[0-9]*", sub_part)
if number is None:
return default
return float(number.group(0))
class GCodeStep():
"""
Class to store the current value of each G_Code parameter
for any G-Code step
"""
def __init__(self, step, in_relative_movement: bool = False) -> None:
self.step = step
self.step_x = 0
self.step_y = 0
self.step_z = 0
self.step_e = 0
self.step_f = 0
self.in_relative_movement = in_relative_movement
self.comment = ""
def readStep(self, line):
"""
Reads gcode from line into self
"""
if not self.in_relative_movement:
self.step_x = _getValue(line, "X", self.step_x)
self.step_y = _getValue(line, "Y", self.step_y)
self.step_z = _getValue(line, "Z", self.step_z)
self.step_e = _getValue(line, "E", self.step_e)
self.step_f = _getValue(line, "F", self.step_f)
else:
delta_step_x = _getValue(line, "X", 0)
delta_step_y = _getValue(line, "Y", 0)
delta_step_z = _getValue(line, "Z", 0)
delta_step_e = _getValue(line, "E", 0)
self.step_x += delta_step_x
self.step_y += delta_step_y
self.step_z += delta_step_z
self.step_e += delta_step_e
self.step_f = _getValue(line, "F", self.step_f) # the feedrate is not relative
def copyPosFrom(self, step):
"""
Copies positions of step into self
"""
self.step_x = step.step_x
self.step_y = step.step_y
self.step_z = step.step_z
self.step_e = step.step_e
self.step_f = step.step_f
self.comment = step.comment
def setInRelativeMovement(self, value: bool) -> None:
self.in_relative_movement = value
# Execution part of the stretch plugin
class Stretcher:
"""
Execution part of the stretch algorithm
"""
def __init__(self, line_width, wc_stretch, pw_stretch):
self.line_width = line_width
self.wc_stretch = wc_stretch
self.pw_stretch = pw_stretch
if self.pw_stretch > line_width / 4:
self.pw_stretch = line_width / 4 # Limit value of pushwall stretch distance
self.outpos = GCodeStep(0)
self.vd1 = np.empty((0, 2)) # Start points of segments
# of already deposited material for current layer
self.vd2 = np.empty((0, 2)) # End points of segments
# of already deposited material for current layer
self.layer_z = 0 # Z position of the extrusion moves of the current layer
self.layergcode = ""
self._in_relative_movement = False
def execute(self, data):
"""
Computes the new X and Y coordinates of all g-code steps
"""
Logger.log("d", "Post stretch with line width " + str(self.line_width)
+ "mm wide circle stretch " + str(self.wc_stretch)+ "mm"
+ " and push wall stretch " + str(self.pw_stretch) + "mm")
retdata = []
layer_steps = []
in_relative_movement = False
current = GCodeStep(0, in_relative_movement)
self.layer_z = 0.
current_e = 0.
for layer in data:
lines = layer.rstrip("\n").split("\n")
for line in lines:
current.comment = ""
if line.find(";") >= 0:
current.comment = line[line.find(";"):]
if _getValue(line, "G") == 0:
current.readStep(line)
onestep = GCodeStep(0, in_relative_movement)
onestep.copyPosFrom(current)
elif _getValue(line, "G") == 1:
last_x = current.step_x
last_y = current.step_y
last_z = current.step_z
last_e = current.step_e
current.readStep(line)
if (current.step_x == last_x and current.step_y == last_y and
current.step_z == last_z and current.step_e != last_e
):
# It's an extruder only move. Preserve it rather than process it as an
# extruded move. Otherwise, the stretched output might contain slight
# motion in X and Y in addition to E. This can cause problems with
# firmwares that implement pressure advance.
onestep = GCodeStep(-1, in_relative_movement)
onestep.copyPosFrom(current)
# Rather than copy the original line, write a new one with consistent
# extruder coordinates
onestep.comment = "G1 F{} E{}".format(onestep.step_f, onestep.step_e)
else:
onestep = GCodeStep(1, in_relative_movement)
onestep.copyPosFrom(current)
# end of relative movement
elif _getValue(line, "G") == 90:
in_relative_movement = False
current.setInRelativeMovement(in_relative_movement)
# start of relative movement
elif _getValue(line, "G") == 91:
in_relative_movement = True
current.setInRelativeMovement(in_relative_movement)
elif _getValue(line, "G") == 92:
current.readStep(line)
onestep = GCodeStep(-1, in_relative_movement)
onestep.copyPosFrom(current)
onestep.comment = line
else:
onestep = GCodeStep(-1, in_relative_movement)
onestep.copyPosFrom(current)
onestep.comment = line
if line.find(";LAYER:") >= 0 and len(layer_steps):
# Previous plugin "forgot" to separate two layers...
Logger.log("d", "Layer Z " + "{:.3f}".format(self.layer_z)
+ " " + str(len(layer_steps)) + " steps")
retdata.append(self.processLayer(layer_steps))
layer_steps = []
layer_steps.append(onestep)
# self.layer_z is the z position of the last extrusion move (not travel move)
if current.step_z != self.layer_z and current.step_e != current_e:
self.layer_z = current.step_z
current_e = current.step_e
if len(layer_steps): # Force a new item in the array
Logger.log("d", "Layer Z " + "{:.3f}".format(self.layer_z)
+ " " + str(len(layer_steps)) + " steps")
retdata.append(self.processLayer(layer_steps))
layer_steps = []
retdata.append(";Wide circle stretch distance " + str(self.wc_stretch) + "\n")
retdata.append(";Push wall stretch distance " + str(self.pw_stretch) + "\n")
return retdata
def extrusionBreak(self, layer_steps, i_pos):
"""
Returns true if the command layer_steps[i_pos] breaks the extruded filament
i.e. it is a travel move
"""
if i_pos == 0:
return True # Begining a layer always breaks filament (for simplicity)
step = layer_steps[i_pos]
prev_step = layer_steps[i_pos - 1]
if step.step_e != prev_step.step_e:
return False
delta_x = step.step_x - prev_step.step_x
delta_y = step.step_y - prev_step.step_y
if delta_x * delta_x + delta_y * delta_y < self.line_width * self.line_width / 4:
# This is a very short movement, less than 0.5 * line_width
# It does not break filament, we should stay in the same extrusion sequence
return False
return True # New sequence
def processLayer(self, layer_steps):
"""
Computes the new coordinates of g-code steps
for one layer (all the steps at the same Z coordinate)
"""
self.outpos.step_x = -1000 # Force output of X and Y coordinates
self.outpos.step_y = -1000 # at each start of layer
self.layergcode = ""
self.vd1 = np.empty((0, 2))
self.vd2 = np.empty((0, 2))
orig_seq = np.empty((0, 2))
modif_seq = np.empty((0, 2))
iflush = 0
for i, step in enumerate(layer_steps):
if step.step == 0 or step.step == 1:
if self.extrusionBreak(layer_steps, i):
# No extrusion since the previous step, so it is a travel move
# Let process steps accumulated into orig_seq,
# which are a sequence of continuous extrusion
modif_seq = np.copy(orig_seq)
if len(orig_seq) >= 2:
self.workOnSequence(orig_seq, modif_seq)
self.generate(layer_steps, iflush, i, modif_seq)
iflush = i
orig_seq = np.empty((0, 2))
orig_seq = np.concatenate([orig_seq, np.array([[step.step_x, step.step_y]])])
if len(orig_seq):
modif_seq = np.copy(orig_seq)
if len(orig_seq) >= 2:
self.workOnSequence(orig_seq, modif_seq)
self.generate(layer_steps, iflush, len(layer_steps), modif_seq)
return self.layergcode
def stepToGcode(self, onestep):
"""
Converts a step into G-Code
For each of the X, Y, Z, E and F parameter,
the parameter is written only if its value changed since the
previous g-code step.
"""
sout = ""
if onestep.step_f != self.outpos.step_f:
self.outpos.step_f = onestep.step_f
sout += " F{:.0f}".format(self.outpos.step_f).rstrip(".")
if onestep.step_x != self.outpos.step_x or onestep.step_y != self.outpos.step_y:
assert onestep.step_x >= -1000 and onestep.step_x < 1000 # If this assertion fails,
# something went really wrong !
self.outpos.step_x = onestep.step_x
sout += " X{:.3f}".format(self.outpos.step_x).rstrip("0").rstrip(".")
assert onestep.step_y >= -1000 and onestep.step_y < 1000 # If this assertion fails,
# something went really wrong !
self.outpos.step_y = onestep.step_y
sout += " Y{:.3f}".format(self.outpos.step_y).rstrip("0").rstrip(".")
if onestep.step_z != self.outpos.step_z or onestep.step_z != self.layer_z:
self.outpos.step_z = onestep.step_z
sout += " Z{:.3f}".format(self.outpos.step_z).rstrip("0").rstrip(".")
if onestep.step_e != self.outpos.step_e:
self.outpos.step_e = onestep.step_e
sout += " E{:.5f}".format(self.outpos.step_e).rstrip("0").rstrip(".")
return sout
def generate(self, layer_steps, ibeg, iend, orig_seq):
"""
Appends g-code lines to the plugin's returned string
starting from step ibeg included and until step iend excluded
"""
ipos = 0
for i in range(ibeg, iend):
if layer_steps[i].step == 0:
layer_steps[i].step_x = orig_seq[ipos][0]
layer_steps[i].step_y = orig_seq[ipos][1]
sout = "G0" + self.stepToGcode(layer_steps[i])
self.layergcode = self.layergcode + sout + "\n"
ipos = ipos + 1
elif layer_steps[i].step == 1:
layer_steps[i].step_x = orig_seq[ipos][0]
layer_steps[i].step_y = orig_seq[ipos][1]
sout = "G1" + self.stepToGcode(layer_steps[i])
self.layergcode = self.layergcode + sout + "\n"
ipos = ipos + 1
else:
# The command is intended to be passed through unmodified via
# the comment field. In the case of an extruder only move, though,
# the extruder and potentially the feed rate are modified.
# We need to update self.outpos accordingly so that subsequent calls
# to stepToGcode() knows about the extruder and feed rate change.
self.outpos.step_e = layer_steps[i].step_e
self.outpos.step_f = layer_steps[i].step_f
self.layergcode = self.layergcode + layer_steps[i].comment + "\n"
def workOnSequence(self, orig_seq, modif_seq):
"""
Computes new coordinates for a sequence
A sequence is a list of consecutive g-code steps
of continuous material extrusion
"""
d_contact = self.line_width / 2.0
if (len(orig_seq) > 2 and
((orig_seq[len(orig_seq) - 1] - orig_seq[0]) ** 2).sum(0) < d_contact * d_contact):
# Starting and ending point of the sequence are nearby
# It is a closed loop
#self.layergcode = self.layergcode + ";wideCircle\n"
self.wideCircle(orig_seq, modif_seq)
else:
#self.layergcode = self.layergcode + ";wideTurn\n"
self.wideTurn(orig_seq, modif_seq) # It is an open curve
if len(orig_seq) > 6: # Don't try push wall on a short sequence
self.pushWall(orig_seq, modif_seq)
if len(orig_seq):
self.vd1 = np.concatenate([self.vd1, np.array(orig_seq[:-1])])
self.vd2 = np.concatenate([self.vd2, np.array(orig_seq[1:])])
def wideCircle(self, orig_seq, modif_seq):
"""
Similar to wideTurn
The first and last point of the sequence are the same,
so it is possible to extend the end of the sequence
with its beginning when seeking for triangles
It is necessary to find the direction of the curve, knowing three points (a triangle)
If the triangle is not wide enough, there is a huge risk of finding
an incorrect orientation, due to insufficient accuracy.
So, when the consecutive points are too close, the method
use following and preceding points to form a wider triangle around
the current point
dmin_tri is the minimum distance between two consecutive points
of an acceptable triangle
"""
dmin_tri = 0.5
iextra_base = np.floor_divide(len(orig_seq), 3) # Nb of extra points
ibeg = 0 # Index of first point of the triangle
iend = 0 # Index of the third point of the triangle
for i, step in enumerate(orig_seq):
if i == 0 or i == len(orig_seq) - 1:
# First and last point of the sequence are the same,
# so it is necessary to skip one of these two points
# when creating a triangle containing the first or the last point
iextra = iextra_base + 1
else:
iextra = iextra_base
# i is the index of the second point of the triangle
# pos_after is the array of positions of the original sequence
# after the current point
pos_after = np.resize(np.roll(orig_seq, -i-1, 0), (iextra, 2))
# Vector of distances between the current point and each following point
dist_from_point = ((step - pos_after) ** 2).sum(1)
if np.amax(dist_from_point) < dmin_tri * dmin_tri:
continue
iend = np.argmax(dist_from_point >= dmin_tri * dmin_tri)
# pos_before is the array of positions of the original sequence
# before the current point
pos_before = np.resize(np.roll(orig_seq, -i, 0)[::-1], (iextra, 2))
# This time, vector of distances between the current point and each preceding point
dist_from_point = ((step - pos_before) ** 2).sum(1)
if np.amax(dist_from_point) < dmin_tri * dmin_tri:
continue
ibeg = np.argmax(dist_from_point >= dmin_tri * dmin_tri)
# See https://github.com/electrocbd/post_stretch for explanations
# relpos is the relative position of the projection of the second point
# of the triangle on the segment from the first to the third point
# 0 means the position of the first point, 1 means the position of the third,
# intermediate values are positions between
length_base = ((pos_after[iend] - pos_before[ibeg]) ** 2).sum(0)
relpos = ((step - pos_before[ibeg])
* (pos_after[iend] - pos_before[ibeg])).sum(0)
if np.fabs(relpos) < 1000.0 * np.fabs(length_base):
relpos /= length_base
else:
relpos = 0.5 # To avoid division by zero or precision loss
projection = (pos_before[ibeg] + relpos * (pos_after[iend] - pos_before[ibeg]))
dist_from_proj = np.sqrt(((projection - step) ** 2).sum(0))
if dist_from_proj > 0.0003: # Move central point only if points are not aligned
modif_seq[i] = (step - (self.wc_stretch / dist_from_proj)
* (projection - step))
return
def wideTurn(self, orig_seq, modif_seq):
'''
We have to select three points in order to form a triangle
These three points should be far enough from each other to have
a reliable estimation of the orientation of the current turn
'''
dmin_tri = self.line_width / 2.0
ibeg = 0
iend = 2
for i in range(1, len(orig_seq) - 1):
dist_from_point = ((orig_seq[i] - orig_seq[i+1:]) ** 2).sum(1)
if np.amax(dist_from_point) < dmin_tri * dmin_tri:
continue
iend = i + 1 + np.argmax(dist_from_point >= dmin_tri * dmin_tri)
dist_from_point = ((orig_seq[i] - orig_seq[i-1::-1]) ** 2).sum(1)
if np.amax(dist_from_point) < dmin_tri * dmin_tri:
continue
ibeg = i - 1 - np.argmax(dist_from_point >= dmin_tri * dmin_tri)
length_base = ((orig_seq[iend] - orig_seq[ibeg]) ** 2).sum(0)
relpos = ((orig_seq[i] - orig_seq[ibeg]) * (orig_seq[iend] - orig_seq[ibeg])).sum(0)
if np.fabs(relpos) < 1000.0 * np.fabs(length_base):
relpos /= length_base
else:
relpos = 0.5
projection = orig_seq[ibeg] + relpos * (orig_seq[iend] - orig_seq[ibeg])
dist_from_proj = np.sqrt(((projection - orig_seq[i]) ** 2).sum(0))
if dist_from_proj > 0.001:
modif_seq[i] = (orig_seq[i] - (self.wc_stretch / dist_from_proj)
* (projection - orig_seq[i]))
return
def pushWall(self, orig_seq, modif_seq):
"""
The algorithm tests for each segment if material was
already deposited at one or the other side of this segment.
If material was deposited at one side but not both,
the segment is moved into the direction of the deposited material,
to "push the wall"
Already deposited material is stored as segments.
vd1 is the array of the starting points of the segments
vd2 is the array of the ending points of the segments
For example, segment nr 8 starts at position self.vd1[8]
and ends at position self.vd2[8]
"""
dist_palp = self.line_width # Palpation distance to seek for a wall
mrot = np.array([[0, -1], [1, 0]]) # Rotation matrix for a quarter turn
for i in range(len(orig_seq)):
ibeg = i # Index of the first point of the segment
iend = i + 1 # Index of the last point of the segment
if iend == len(orig_seq):
iend = i - 1
xperp = np.dot(mrot, orig_seq[iend] - orig_seq[ibeg])
xperp = xperp / np.sqrt((xperp ** 2).sum(-1))
testleft = orig_seq[ibeg] + xperp * dist_palp
materialleft = False # Is there already extruded material at the left of the segment
testright = orig_seq[ibeg] - xperp * dist_palp
materialright = False # Is there already extruded material at the right of the segment
if self.vd1.shape[0]:
relpos = np.clip(((testleft - self.vd1) * (self.vd2 - self.vd1)).sum(1)
/ ((self.vd2 - self.vd1) * (self.vd2 - self.vd1)).sum(1), 0., 1.)
nearpoints = self.vd1 + relpos[:, np.newaxis] * (self.vd2 - self.vd1)
# nearpoints is the array of the nearest points of each segment
# from the point testleft
dist = ((testleft - nearpoints) * (testleft - nearpoints)).sum(1)
# dist is the array of the squares of the distances between testleft
# and each segment
if np.amin(dist) <= dist_palp * dist_palp:
materialleft = True
# Now the same computation with the point testright at the other side of the
# current segment
relpos = np.clip(((testright - self.vd1) * (self.vd2 - self.vd1)).sum(1)
/ ((self.vd2 - self.vd1) * (self.vd2 - self.vd1)).sum(1), 0., 1.)
nearpoints = self.vd1 + relpos[:, np.newaxis] * (self.vd2 - self.vd1)
dist = ((testright - nearpoints) * (testright - nearpoints)).sum(1)
if np.amin(dist) <= dist_palp * dist_palp:
materialright = True
if materialleft and not materialright:
modif_seq[ibeg] = modif_seq[ibeg] + xperp * self.pw_stretch
elif not materialleft and materialright:
modif_seq[ibeg] = modif_seq[ibeg] - xperp * self.pw_stretch
# Setup part of the stretch plugin
class Stretch(Script):
"""
Setup part of the stretch algorithm
The only parameter is the stretch distance
"""
def __init__(self):
super().__init__()
def getSettingDataString(self):
return """{
"name":"Post stretch script",
"key": "Stretch",
"metadata": {},
"version": 2,
"settings":
{
"wc_stretch":
{
"label": "Wide circle stretch distance",
"description": "Distance by which the points are moved by the correction effect in corners. The higher this value, the higher the effect",
"unit": "mm",
"type": "float",
"default_value": 0.1,
"minimum_value": 0,
"minimum_value_warning": 0,
"maximum_value_warning": 0.2
},
"pw_stretch":
{
"label": "Push Wall stretch distance",
"description": "Distance by which the points are moved by the correction effect when two lines are nearby. The higher this value, the higher the effect",
"unit": "mm",
"type": "float",
"default_value": 0.1,
"minimum_value": 0,
"minimum_value_warning": 0,
"maximum_value_warning": 0.2
}
}
}"""
def execute(self, data):
"""
Entry point of the plugin.
data is the list of original g-code instructions,
the returned string is the list of modified g-code instructions
"""
stretcher = Stretcher(
ExtruderManager.getInstance().getActiveExtruderStack().getProperty("machine_nozzle_size", "value")
, self.getSettingValueByKey("wc_stretch"), self.getSettingValueByKey("pw_stretch"))
return stretcher.execute(data)