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Postprocessing script to make FreeCAD paths importible by Easel (WIP)
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| # *************************************************************************** | |
| # * (c) Benno Evers (bennoe@apache.org) 2019 * | |
| # * * | |
| # * This file is part of the FreeCAD CAx development system. * | |
| # * * | |
| # * 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. * | |
| # * * | |
| # * FreeCAD 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 Lesser General Public License for more details. * | |
| # * * | |
| # * You should have received a copy of the GNU Library General Public * | |
| # * License along with FreeCAD; if not, write to the Free Software * | |
| # * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 * | |
| # * USA * | |
| # * * | |
| # ***************************************************************************/ | |
| from __future__ import print_function | |
| TOOLTIP=''' | |
| This is a post-processor for the Easel WebUI which can control various | |
| models of CNC mills, i.e. Carvey, X-Carve and ShapeOko 1/2. | |
| Note that it has only been tested with the Carvey. | |
| Its main task is to linearize any arcs, since Easel only | |
| supports linear movements. | |
| ''' | |
| import datetime | |
| import FreeCAD | |
| import Part | |
| import PathScripts.PostUtils as PostUtils | |
| def export(objectslist, filename, argstring): | |
| "Called when freecad exports a list of objects" | |
| # TODO(bevers): Support multiple paths by concatenating them together. | |
| if len(objectslist) > 1: | |
| print("This script is unable to write more than one Path object") | |
| return | |
| obj = objectslist[0] | |
| if not hasattr(obj, "Path"): | |
| print("the given object is not a path") | |
| return | |
| # The `Path.toGCode()` function returns a string formatted in the FreeCAD | |
| # internal GCode dialect | |
| #freecad_gcode = obj.Path.toGCode() | |
| easel_gcode = postprocess(obj.Path.Commands) | |
| dia = PostUtils.GCodeEditorDialog() | |
| dia.editor.setText(easel_gcode) | |
| result = dia.exec_() | |
| gfile = open(filename, "w") | |
| gfile.write(easel_gcode) | |
| gfile.close() | |
| return result | |
| def linearize_arc(start_dict, end_dict, center_dict, clockwise): | |
| result = "; {} arc from {} to {}\n; around center point {}\n".format( | |
| "Clockwise" if clockwise else "Counter-clockwise", | |
| start_dict, | |
| end_dict, | |
| center_dict) | |
| start = FreeCAD.Vector(start_dict['X'], start_dict['Y'], start_dict['Z']) | |
| end = FreeCAD.Vector(end_dict['X'], end_dict['Y'], end_dict['Z']) | |
| center = FreeCAD.Vector(center_dict['X'], center_dict['Y'], center_dict['Z']) | |
| if clockwise: | |
| start, end = end, start | |
| radius = (center - start).Length | |
| normal = (center - start).cross(center - end) | |
| # Special case: If the circle is under-specified (i.e. 180 or 360 degree angles), | |
| # we construct the normal | |
| # This ensures we're getting the z-axis as normal when start and center lie in the same z-plane. | |
| # This will break for circles on the xz or yz planes, but these don't make physical sense on a CNC mill. | |
| # TODO: Warn if we hit this condition. | |
| if (normal.Length == 0.): | |
| to_center = center - start | |
| reference = FreeCAD.Vector(to_center.y, -to_center.x, to_center.z) | |
| normal = to_center.cross(reference) | |
| normal.normalize() | |
| # TODO: Looks like we need to switch to the 3-point form to | |
| # reliably handle semi-circles and such. | |
| circle = Part.Circle(center, normal, radius) | |
| p0 = circle.parameter(start) | |
| p1 = circle.parameter(end) | |
| arc = Part.ArcOfCircle(circle, p0, p1) | |
| steps = 64 # TODO: make number of steps configurable | |
| points = arc.discretize(steps) | |
| c = [] | |
| for p in points: | |
| c.append("G1 X{} Y{} Z{}\n".format(p.x, p.y, p.z)) | |
| if clockwise: | |
| c.reverse() | |
| return result + "".join(c) + "\n" | |
| # `gcode`: [FreeCAD...Command] | |
| def postprocess(commands): | |
| output = "; Generated by FreeCAD Easel post-processor.\n" | |
| output += "G21 ; Metric units\n" # FreeCAD internal values are always metric. | |
| # Currently supported internal commands: | |
| # G0, G1, G2, G3 (movement commands) | |
| # G81, G82, G83 (drilling commands) | |
| # G90, G91 (absolute/relative coordinates) | |
| # Carvey starts at (20mm, 20mm, 20mm) after smart-clamp calibration. | |
| # TODO: Check if this is different for the other easel-supported machines. | |
| state = {'X': 20., 'Y': 20., 'Z': 20.} | |
| for cmd in commands: | |
| if cmd.Name[0] == "(": | |
| output += "; " + cmd.Name + "\n" | |
| elif cmd.Name == "G0" or cmd.Name == "G1": | |
| argnames = cmd.Parameters.keys() | |
| if 'A' in argnames or 'B' in argnames or 'C' in argnames: | |
| raise RuntimeError("A,B,C rotational axes currently not supported.") | |
| if 'X' in argnames: | |
| state['X'] = float(cmd.Parameters['X']) | |
| if 'Y' in argnames: | |
| state['Y'] = float(cmd.Parameters['Y']) | |
| if 'Z' in argnames: | |
| state['Z'] = float(cmd.Parameters['Z']) | |
| # TODO: Is it important to omit duplicate coordinates? | |
| output += "{} X{} Y{} Z{}\n".format(cmd.Name, state['X'], state['Y'], state['Z']) | |
| elif cmd.Name == "G2" or cmd.Name == "G3": | |
| argnames = cmd.Parameters.keys() | |
| if 'A' in argnames or 'B' in argnames or 'C' in argnames: | |
| raise RuntimeError("A,B,C rotational axes currently not supported.") | |
| center_x = state['X'] + cmd.Parameters['I'] | |
| center_y = state['Y'] + cmd.Parameters['J'] | |
| center_z = state['Z'] | |
| if 'K' in argnames: # 'K' is optional | |
| center_z = state['Z'] + cmd.Parameters['K'] | |
| # Update final position | |
| start_position = dict(state) | |
| end_position = dict(state) | |
| if 'X' in argnames: | |
| end_position['X'] = float(cmd.Parameters['X']) | |
| if 'Y' in argnames: | |
| end_position['Y'] = float(cmd.Parameters['Y']) | |
| if 'Z' in argnames: | |
| end_position['Z'] = float(cmd.Parameters['Z']) | |
| clockwise = cmd.Name == "G2" | |
| center = {'X': center_x, 'Y': center_y, 'Z': center_z} | |
| output += linearize_arc(start_position, end_position, center, clockwise) | |
| state = end_position | |
| elif cmd.Name == "G81" or cmd.Name == "G82" or cmd.Name == "G83": | |
| raise RuntimeError("Drilling commands (G8x) currently not supported.") | |
| elif cmd.Name == "G90": | |
| output += "G90 ; Absolute coordinate mode\n" | |
| elif cmd.Name == "G91": | |
| raise RuntimeError("Relative coordinate mode (G91) currently not supported.") | |
| return output | |
| print(__name__ + " gcode postprocessor loaded.") |
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