"""BlenderCAM 'gcodeimportparser.py'
Code modified from YAGV (Yet Another G-code Viewer) - https://github.com/jonathanwin/yagv
No license terms found in YAGV repo, will assume GNU release
"""
import math
import numpy as np
import bpy
np.set_printoptions(suppress=True) # suppress scientific notation in subdivide functions linspace
[docs]
def import_gcode(context, filepath):
"""Import G-code data into the scene.
This function reads G-code from a specified file and processes it
according to the settings defined in the context. It utilizes the
GcodeParser to parse the file and classify segments of the model.
Depending on the options set in the scene, it may subdivide the model
and draw it with or without layer splitting. The time taken for the
import process is printed to the console.
Args:
context (Context): The context containing the scene and tool settings.
filepath (str): The path to the G-code file to be imported.
Returns:
dict: A dictionary indicating the import status, typically
{'FINISHED'}.
"""
print("Running read_some_data...")
scene = context.scene
mytool = scene.cam_import_gcode
import time
then = time.time()
parse = GcodeParser()
model = parse.parseFile(filepath)
if mytool.subdivide:
model.subdivide(mytool.max_segment_size)
model.classifySegments()
if mytool.split_layers:
model.draw(split_layers=True)
else:
model.draw(split_layers=False)
now = time.time()
print("Importing Gcode Took ", round(now - then, 1), "Seconds")
return {'FINISHED'}
[docs]
def segments_to_meshdata(segments):
"""Convert a list of segments into mesh data consisting of vertices and
edges.
This function processes a list of segment objects, extracting the
coordinates of vertices and defining edges based on the styles of the
segments. It identifies when to add vertices and edges based on whether
the segments are in 'extrude' or 'travel' styles. The resulting mesh
data can be used for 3D modeling or rendering applications.
Args:
segments (list): A list of segment objects, each containing 'style' and
'coords' attributes.
Returns:
tuple: A tuple containing two elements:
- list: A list of vertices, where each vertex is represented as a
list of coordinates [X, Y, Z].
- list: A list of edges, where each edge is represented as a list
of indices corresponding to the vertices.
"""
# edges only on extrusion
segs = segments
verts = []
edges = []
del_offset = 0 # to travel segs in a row, one gets deleted, need to keep track of index for edges
for i in range(len(segs)):
if i >= len(segs) - 1:
if segs[i].style == 'extrude':
verts.append([segs[i].coords['X'], segs[i].coords['Y'], segs[i].coords['Z']])
break
# start of extrusion for first time
if segs[i].style == 'travel' and segs[i + 1].style == 'extrude':
verts.append([segs[i].coords['X'], segs[i].coords['Y'], segs[i].coords['Z']])
verts.append([segs[i + 1].coords['X'], segs[i + 1].coords['Y'], segs[i + 1].coords['Z']])
edges.append([i - del_offset, (i - del_offset) + 1])
# mitte, current and next are extrusion, only add next, current is already in vert list
if segs[i].style == 'extrude' and segs[i + 1].style == 'extrude':
verts.append([segs[i + 1].coords['X'], segs[i + 1].coords['Y'], segs[i + 1].coords['Z']])
edges.append([i - del_offset, (i - del_offset) + 1])
if segs[i].style == 'travel' and segs[i + 1].style == 'travel':
del_offset += 1
return verts, edges
[docs]
def obj_from_pydata(name, verts, edges=None, close=True, collection_name=None):
"""Create a Blender object from provided vertex and edge data.
This function generates a mesh object in Blender using the specified
vertices and edges. If edges are not provided, it automatically creates
a chain of edges connecting the vertices. The function also allows for
the option to close the mesh by connecting the last vertex back to the
first. Additionally, it can place the created object into a specified
collection within the Blender scene. The object is scaled down to a
smaller size for better visibility in the Blender environment.
Args:
name (str): The name of the object to be created.
verts (list): A list of vertex coordinates, where each vertex is represented as a
tuple of (x, y, z).
edges (list?): A list of edges defined by pairs of vertex indices. Defaults to None.
close (bool?): Whether to close the mesh by connecting the last vertex to the first.
Defaults to True.
collection_name (str?): The name of the collection to which the object should be added. Defaults
to None.
Returns:
None: The function does not return a value; it creates an object in the
Blender scene.
"""
if edges is None:
# join vertices into one uninterrupted chain of edges.
edges = [[i, i + 1] for i in range(len(verts) - 1)]
if close:
edges.append([len(verts) - 1, 0]) # connect last to first
me = bpy.data.meshes.new(name)
me.from_pydata(verts, edges, [])
obj = bpy.data.objects.new(name, me)
# Move into collection if specified
if collection_name is not None: # make argument optional
# collection exists
collection = bpy.data.collections.get(collection_name)
if collection:
bpy.data.collections[collection_name].objects.link(obj)
else:
collection = bpy.data.collections.new(collection_name)
bpy.context.scene.collection.children.link(collection) # link collection to main scene
bpy.data.collections[collection_name].objects.link(obj)
obj.scale = (0.001, 0.001, 0.001)
bpy.context.view_layer.objects.active = obj
obj.select_set(True)
bpy.ops.object.transform_apply(location=False, rotation=False, scale=True)
if bpy.context.scene.cam_import_gcode.output == 'curve':
bpy.ops.object.convert(target='CURVE')
[docs]
class GcodeParser:
# global, to access in other classes(to access RGB values in comment above when parsing M163).
# Theres probably better way
def __init__(self):
[docs]
self.model = GcodeModel(self)
[docs]
def parseFile(self, path):
"""Parse a G-code file and update the model.
This function reads a G-code file line by line, increments a line
counter for each line, and processes each line using the `parseLine`
method. The function assumes that the file is well-formed and that each
line can be parsed without errors. After processing all lines, it
returns the updated model.
Args:
path (str): The file path to the G-code file to be parsed.
Returns:
model: The updated model after parsing the G-code file.
"""
# read the gcode file
with open(path, 'r') as f:
# init line counter
self.lineNb = 0
# for all lines
for line in f:
# inc line counter
self.lineNb += 1
# remove trailing linefeed
self.line = line.rstrip()
# parse a line
self.parseLine()
return self.model
[docs]
def parseLine(self):
"""Parse a line of G-code and execute the corresponding command.
This method processes a line of G-code by stripping comments, cleaning
the command, and identifying the command code and its arguments. It
handles specific G-code commands and invokes the appropriate parsing
method if available. If the command is unsupported, it prints an error
message. The method also manages tool numbers and coordinates based on
the parsed command.
"""
# strip comments:
bits = self.line.split(';', 1)
if (len(bits) > 1):
GcodeParser.comment = bits[1]
# extract & clean command
command = bits[0].strip()
s = ""
a = ""
a_old = ""
for i in range(len(command)): # check each character in the line
a = command[i]
if a.isupper() and a_old != ' ' and i > 0: # add a space if upper case letter and no space is found before
s += ' '
s += a
a_old = a
print(s)
command = s
# code is fist word, then args
comm = command.split(None, 1)
code = comm[0] if (len(comm) > 0) else None
args = comm[1] if (len(comm) > 1) else None
if code:
# convert all G01 and G00 to G1 and G0
if code == 'G01':
code = 'G1'
if code == 'G00':
code = 'G0'
if hasattr(self, "parse_" + code):
getattr(self, "parse_" + code)(args)
self.last_command = code
else:
if code[0] == "T":
self.model.toolnumber = int(code[1:])
print(self.model.toolnumber)
# if code doesn't start with a G but starts with a coordinate add the last command to the line
elif code[0] == 'X' or code[0] == 'Y' or code[0] == 'Z':
self.line = self.last_command + ' ' + self.line
self.parseLine() # parse this line again with the corrections
else:
pass
print("Unsupported gcode " + str(code))
[docs]
def parseArgs(self, args):
"""Parse command-line arguments into a dictionary.
This function takes a string of arguments, splits it into individual
components, and maps each component's first character to its
corresponding numeric value. If a numeric value cannot be converted from
the string, it defaults to 1. The resulting dictionary contains the
first characters as keys and their associated numeric values as values.
Args:
args (str): A string of space-separated arguments, where each argument
consists of a letter followed by a numeric value.
Returns:
dict: A dictionary mapping each letter to its corresponding numeric value.
"""
dic = {}
if args:
bits = args.split()
for bit in bits:
letter = bit[0]
try:
coord = float(bit[1:])
except ValueError:
coord = 1
dic[letter] = coord
return dic
[docs]
def parse_G1(self, args, type="G1"):
# G1: Controlled move
self.model.do_G1(self.parseArgs(args), type)
[docs]
def parse_G0(self, args, type="G0"):
# G1: Controlled move
self.model.do_G1(self.parseArgs(args), type)
[docs]
def parse_G90(self, args):
# G90: Set to Absolute Positioning
self.model.setRelative(False)
[docs]
def parse_G91(self, args):
# G91: Set to Relative Positioning
self.model.setRelative(True)
[docs]
def parse_G92(self, args):
# G92: Set Position
self.model.do_G92(self.parseArgs(args))
[docs]
def warn(self, msg):
print("[WARN] Line %d: %s (Text:'%s')" % (self.lineNb, msg, self.line))
[docs]
def error(self, msg):
"""Log an error message and raise an exception.
This method prints an error message to the console, including the line
number, the provided message, and the text associated with the error.
After logging the error, it raises a generic Exception with the same
message format.
Args:
msg (str): The error message to be logged.
Raises:
Exception: Always raises an Exception with the formatted error message.
"""
print("[ERROR] Line %d: %s (Text:'%s')" % (self.lineNb, msg, self.line))
raise Exception("[ERROR] Line %d: %s (Text:'%s')" % (self.lineNb, msg, self.line))
[docs]
class GcodeModel:
def __init__(self, parser):
# save parser for messages
# latest coordinates & extrusion relative to offset, feedrate
[docs]
self.relative = {
"X": 0.0,
"Y": 0.0,
"Z": 0.0,
"F": 0.0,
"E": 0.0}
# offsets for relative coordinates and position reset (G92)
[docs]
self.offset = {
"X": 0.0,
"Y": 0.0,
"Z": 0.0,
"E": 0.0}
# if true, args for move (G1) are given relatively (default: absolute)
[docs]
self.isRelative = False
[docs]
self.color = [0, 0, 0, 0, 0, 0, 0, 0] # RGBCMYKW
# the segments
[docs]
def do_G1(self, args, type):
"""Perform a rapid or controlled movement based on the provided arguments.
This method updates the current coordinates based on the input
arguments, either in relative or absolute terms. It constructs a segment
representing the movement and adds it to the model if there are changes
in the XYZ coordinates. The function handles unknown axes by issuing a
warning and ensures that the segment is only added if there are actual
changes in position.
Args:
args (dict): A dictionary containing movement parameters for each axis.
type (str): The type of movement (e.g., 'G0' for rapid move, 'G1' for controlled
move).
"""
# G0/G1: Rapid/Controlled move
# clone previous coords
coords = dict(self.relative)
# update changed coords
for axis in args.keys():
# print(coords)
if axis in coords:
if self.isRelative:
coords[axis] += args[axis]
else:
coords[axis] = args[axis]
else:
self.warn("Unknown axis '%s'" % axis)
# build segment
absolute = {
"X": self.offset["X"] + coords["X"],
"Y": self.offset["Y"] + coords["Y"],
"Z": self.offset["Z"] + coords["Z"],
"F": coords["F"] # no feedrate offset
}
# if gcode line has no E = travel move
# but still add E = 0 to segment (so coords dictionaries have same shape for subdividing linspace function)
if "E" not in args: # "E" in coords:
absolute["E"] = 0
else:
absolute["E"] = args["E"]
seg = Segment(
type,
absolute,
self.color,
self.toolnumber,
# self.layerIdx,
self.parser.lineNb,
self.parser.line)
# only add seg if XYZ changes (skips "G1 Fxxx" only lines and avoids double vertices inside Blender,
# because XYZ stays the same on such a segment.
if seg.coords['X'] != self.relative['X'] + self.offset["X"] or seg.coords['Y'] != self.relative['Y'] + \
self.offset["Y"] or seg.coords['Z'] != self.relative['Z'] + self.offset["Z"]:
self.addSegment(seg)
# update model coords
self.relative = coords
[docs]
def do_G92(self, args):
"""Set the current position of the axes without moving.
This method updates the current coordinates for the specified axes based
on the provided arguments. If no axes are mentioned, it sets all axes
(X, Y, Z) to zero. The method adjusts the offset values by transferring
the difference between the relative and specified values for each axis.
If an unknown axis is provided, a warning is issued.
Args:
args (dict): A dictionary containing axis names as keys
(e.g., 'X', 'Y', 'Z') and their corresponding
position values as float.
"""
# G92: Set Position
# this changes the current coords, without moving, so do not generate a segment
# no axes mentioned == all axes to 0
if not len(args.keys()):
args = {"X": 0.0, "Y": 0.0, "Z": 0.0} # , "E":0.0
# update specified axes
for axis in args.keys():
if axis in self.offset:
# transfer value from relative to offset
self.offset[axis] += self.relative[axis] - args[axis]
self.relative[axis] = args[axis]
else:
self.warn("Unknown axis '%s'" % axis)
[docs]
def do_M163(self, args):
"""Update the color settings for a specific segment based on given
parameters.
This method modifies the color attributes of an object by updating the
CMYKW values for a specified segment. It first creates a new list from
the existing color attribute to avoid reference issues. The method then
extracts the index and weight from the provided arguments and updates
the color list accordingly. Additionally, it retrieves RGB values from
the last comment and applies them to the color list.
Args:
args (dict): A dictionary containing the parameters for the operation.
- 'S' (int): The index of the segment to update.
- 'P' (float): The weight to set for the CMYKW color component.
Returns:
None: This method does not return a value; it modifies the object's state.
"""
col = list(
self.color) # list() creates new list, otherwise you just change reference and all segs have same color
extr_idx = int(args['S']) # e.g. M163 S0 P1
weight = args['P']
# change CMYKW
col[extr_idx + 3] = weight # +3 weil ersten 3 stellen RGB sind, need only CMYKW values for extrude
self.color = col
# take RGB values for seg from last comment (above first M163 statement)
comment = eval(GcodeParser.comment) # string comment to list
# RGB = [GcodeParser.comment[1], GcodeParser.com
RGB = comment[:3]
self.color[:3] = RGB
[docs]
def setRelative(self, isRelative):
self.isRelative = isRelative
[docs]
def addSegment(self, segment):
self.segments.append(segment)
[docs]
def warn(self, msg):
self.parser.warn(msg)
[docs]
def error(self, msg):
self.parser.error(msg)
[docs]
def classifySegments(self):
"""Classify segments into layers based on their coordinates and extrusion
style.
This method processes a list of segments, determining their extrusion
style (travel, retract, restore, or extrude) based on the movement of
the coordinates and the state of the extruder. It organizes the segments
into layers, which are used for later rendering. The classification is
based on changes in the Z-coordinate and the extruder's position. The
function initializes the coordinates and iterates through each segment,
checking for movements in the X, Y, and Z directions. It identifies when
a new layer begins based on changes in the Z-coordinate and the
extruder's state. Segments are then grouped into layers for further
processing. Raises: None
"""
# start model at 0, act as prev_coords
coords = {
"X": 0.0,
"Y": 0.0,
"Z": 0.0,
"F": 0.0,
"E": 0.0}
# first layer at Z=0
currentLayerIdx = 0
currentLayerZ = 0 # better to use self.first_layer_height
layer = [] # add layer to model.layers
for i, seg in enumerate(self.segments):
# default style is travel (move, no extrusion)
style = "travel"
# no horizontal movement, but extruder movement: retraction/refill
# if (
# (seg.coords["X"] == coords["X"]) and
# (seg.coords["Y"] == coords["Y"]) and
# (seg.coords["Z"] == coords["Z"]) and
# (seg.coords["E"] != coords["E"]) ):
# style = "retract" if (seg.coords["E"] < coords["E"]) else "restore"
# some horizontal movement, and positive extruder movement: extrusion
if (
((seg.coords["X"] != coords["X"]) or (seg.coords["Y"] != coords["Y"]) or (
seg.coords["Z"] != coords["Z"]))): # != coords["E"]
style = "extrude"
# #force extrude if there is some movement
# segments to layer lists
# look ahead and if next seg has E and differenz Z, add new layer for current segment
if i == len(self.segments) - 1:
layer.append(seg)
currentLayerIdx += 1
seg.style = style
seg.layerIdx = currentLayerIdx
# add layer to list of Layers, used to later draw single layer objects
self.layers.append(layer)
break
# positive extruder movement of next point in a different Z signals a layer change for this segment
if self.segments[i].coords["Z"] != currentLayerZ and self.segments[i + 1].coords["E"] > 0:
self.layers.append(
layer) # layer abschließen, add layer to list of Layers, used to later draw single layer objects
layer = [] # start new layer
currentLayerZ = seg.coords["Z"]
currentLayerIdx += 1
# lookback, previous point before texrsuion is part of new layer too, both create an edge
# set style and layer in segment
seg.style = style
seg.layerIdx = currentLayerIdx
layer.append(seg)
coords = seg.coords
[docs]
def subdivide(self, subd_threshold):
"""Subdivide segments based on a specified threshold.
This method processes a list of segments and subdivides them into
smaller segments if the distance between consecutive segments exceeds
the given threshold. The subdivision is performed by interpolating
points between the original segment's coordinates, ensuring that the
resulting segments maintain the original order and properties. This is
particularly useful for manipulating attributes such as color and
continuous deformation in graphical representations.
Args:
subd_threshold (float): The distance threshold for subdividing segments.
Segments with a distance greater than this value
will be subdivided.
Returns:
None: The method modifies the instance's segments attribute in place.
"""
# smart subdivide
# divide edge if > subd_threshold
# do it in parser to keep index order of vertex and travel/extrude info
# segmentation of path necessary for manipulation of color, continous deforming ect.
subdivided_segs = []
# start model at 0
coords = {
"X": 0.0,
"Y": 0.0,
"Z": 0.0,
"F": 0.0, # no interpolation
"E": 0.0}
for seg in self.segments:
# calc XYZ distance
d = (seg.coords["X"] - coords["X"]) ** 2
d += (seg.coords["Y"] - coords["Y"]) ** 2
d += (seg.coords["Z"] - coords["Z"]) ** 2
seg.distance = math.sqrt(d)
if seg.distance > subd_threshold:
subdivs = math.ceil(
seg.distance / subd_threshold) # ceil makes sure that linspace interval is at least 2
P1 = coords
P2 = seg.coords
# interpolated points
interp_coords = np.linspace(list(P1.values()), list(
P2.values()), num=subdivs, endpoint=True)
for i in range(len(interp_coords)): # inteprolated points array back to segment object
new_coords = {"X": interp_coords[i][0], "Y": interp_coords[i][1], "Z": interp_coords[i][2],
"F": seg.coords["F"]}
# E/subdivs is for relative extrusion, absolute extrusion need "E":interp_coords[i][4]
# print("interp_coords_new:", new_coords)
if seg.coords["E"] > 0:
new_coords["E"] = round(seg.coords["E"] / (subdivs - 1), 5)
else:
new_coords["E"] = 0
# make sure P1 hasn't been written before, compare with previous line
if new_coords['X'] != coords['X'] or new_coords['Y'] != coords['Y'] or new_coords['Z'] != \
coords['Z']:
# write segment only if movement changes,
# avoid double coordinates due to same start and endpoint of linspace
new_seg = Segment(seg.type, new_coords, seg.color,
seg.toolnumber, seg.lineNb, seg.line)
new_seg.layerIdx = seg.layerIdx
new_seg.style = seg.style
subdivided_segs.append(new_seg)
else:
subdivided_segs.append(seg)
coords = seg.coords # P1 becomes P2
self.segments = subdivided_segs
# create blender curve and vertex_info in text file(coords, style, color...)
[docs]
def draw(self, split_layers=False):
"""Draws a mesh from segments and layers.
This function creates a Blender curve and vertex information in a text
file, which includes coordinates, style, and color. If the
`split_layers` parameter is set to True, it processes each layer
individually, generating vertices and edges for each layer. If False, it
processes the segments as a whole.
Args:
split_layers (bool): A flag indicating whether to split the drawing into
separate layers or not.
"""
if split_layers:
i = 0
for layer in self.layers:
verts, edges = segments_to_meshdata(layer)
if len(verts) > 0:
obj_from_pydata(str(i), verts, edges, close=False, collection_name="Layers")
i += 1
else:
verts, edges = segments_to_meshdata(self.segments)
obj_from_pydata("Gcode", verts, edges, close=False, collection_name="Layers")
[docs]
class Segment:
def __init__(self, type, coords, color, toolnumber, lineNb, line):
[docs]
def __str__(self):
"""Return a string representation of the object.
This method constructs a string that includes the coordinates, line
number, style, layer index, and color of the object. It formats these
attributes into a readable string format for easier debugging and
logging.
Returns:
str: A formatted string representing the object's attributes.
"""
return " <coords=%s, lineNb=%d, style=%s, layerIdx=%d, color=%s" % \
(str(self.coords), self.lineNb, self.style, self.layerIdx, str(self.color))
[docs]
class Layer:
def __init__(self, Z):
[docs]
def __str__(self):
return "<Layer: Z=%f, len(segments)=%d>" % (self.Z, len(self.segments))
if __name__ == '__main__':
parser = GcodeParser()
model = parser.parseFile(path)
