# This PostProcessingPlugin script is released under the terms of the LGPLv3 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 # Beginning 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 enumerate(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)