Simple utility to convert .s3g files to Wavefront .obj files for preview purposes

scripts/s3g-to-obj.py

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+#!/usr/bin/python
+import struct
+import sys
+
+# Converts a .s3g file to a Wavefront .obj file which can be viewed with
+# Blender or a similar 3D viewer. This allows you to debug / visualize the
+# position of the extruder and the flow or absence of flow of plastic
+# during the print before sending the design to the printer.
+
+# TODO: This was adapted from s3g-decompiler.py and some work needs to be
+# done to refactor so less of the logic is copied and pasted.
+
+# Globals for the OBJ generation
+vertices = 0
+minExtrusion = 0
+faceList = []
+
+def drawPoint(parsed):
+    global vertices, minExtrusion, faceList
+    #print "Absolute move to (%i,%i,%i,%i,%i) at DDA %i" % parsed
+    print "v %f %f %f" % (parsed[0] * 0.0011, parsed[1] * 0.0011, parsed[2] * 0.00025)
+    if parsed[3] < minExtrusion:
+        faceList.append(vertices)
+        minExtrusion = parsed[3]
+    vertices = vertices + 1
+
+toolCommandTable = {
+    3: ("<H", "Set target temperature to %i"),
+    4: ("B", "Set motor 1 speed (pwm): %i"),
+    10: ("B", "Toggle motor 1: %d"),
+    12: ("B", "Turn fan on (1) or off (0): %d"),
+    13: ("B", "Toggle valve: %d"),
+    27: ("B", "Toggle ABP: %d"),
+    31: ("<H", "Set build platform target temperature to %i"),
+    129: ("<iiiI", "Absolute move to (%i,%i,%i) at DDA %i"),
+}
+
+def parseToolAction():
+    global s3gFile
+    packetStr = s3gFile.read(3)
+    if len(packetStr) != 3:
+        raise "Incomplete s3g file during tool command parse"
+    (index,command,payload) = struct.unpack("<BBB",packetStr)
+    contents = s3gFile.read(payload)
+    if len(contents) != payload:
+        raise "Incomplete s3g file: tool packet truncated"
+    return (index,command,contents)
+
+def printToolAction(tuple):
+    #print "Tool %i: " % (tuple[0]),
+    # command - tuple[1]
+    # data - tuple[2]
+    (parse, disp) = toolCommandTable[tuple[1]]
+    if type(parse) == type(""):
+        packetLen = struct.calcsize(parse)
+        if len(tuple[2]) != packetLen:
+            raise "Packet incomplete"
+        parsed = struct.unpack(parse,tuple[2])
+    else:
+        parsed = parse()
+    # if type(disp) == type(""):
+        # print disp % parsed
+
+def parseDisplayMessageAction():
+    global s3gFile
+    packetStr = s3gFile.read(4)
+    if len(packetStr) < 4:
+        raise "Incomplete s3g file during tool command parse"
+    (options,offsetX,offsetY,timeout) = struct.unpack("<BBBB",packetStr)
+    message = "";
+    while True:
+       c = s3gFile.read(1);
+       if c == '\0':
+          break;
+       else:
+          message += c;
+
+    return (options,offsetX,offsetY,timeout,message)
+
+def parseBuildStartNotificationAction():
+    global s3gFile
+    packetStr = s3gFile.read(4)
+    if len(packetStr) < 4:
+        raise "Incomplete s3g file during tool command parse"
+    (steps) = struct.unpack("<i",packetStr)
+    buildName = "";
+    while True:
+       c = s3gFile.read(1);
+       if c == '\0':
+          break;
+       else:
+          buildName += c;
+
+    return (steps[0],buildName)
+
+# Command table entries consist of:
+# * The key: the integer command code
+# * A tuple:
+#   * idx 0: the python struct description of the rest of the data,
+#            of a function that unpacks the remaining data from the
+#            stream
+#   * idx 1: either a format string that will take the tuple of unpacked
+#            data, or a function that takes the tuple as input and returns
+#            a string
+# REMINDER: all values are little-endian. Struct strings with multibyte
+# types should begin with "<".
+# For a refresher on Python struct syntax, see here:
+# http://docs.python.org/library/struct.html
+commandTable = {    
+    129: ("<iiiI", "Absolute move to (%i,%i,%i) at DDA %i"),
+    130: ("<iii","Machine position set as (%i,%i,%i)"),
+    131: ("<BIH","Home minimum on %X, feedrate %i, timeout %i s"),
+    132: ("<BIH","Home maximum on %X, feedrate %i, timeout %i s"),
+    133: ("<I","Delay of %i us"),
+    134: ("<B","Switch to tool %i"),
+    135: ("<BHH","Wait for tool %i (%i ms between polls, %i s timeout"),
+    136: (parseToolAction, printToolAction),
+    137: ("<B", "Enable/disable axes %X"),
+    138: ("<H", "User block on ID %i"),
+    139: ("<iiiiiI",drawPoint),
+    140: ("<iiiii","Extended Machine position set as (%i,%i,%i,%i,%i)"),
+    141: ("<BHH","Wait for platform %i (%i ms between polls, %i s timeout)"),
+    142: ("<iiiiiIB","Move to (%i,%i,%i,%i,%i) in %i us (relative: %X)"),
+    143: ("<b","Store home position for axes %d"),
+    144: ("<b","Recall home position for axes %d"),
+    145: ("<BB","Set pot axis %i to %i"),
+    146: ("<BBBBB","Set RGB led red %i, green %i, blue %i, blink rate %i, effect %i"),
+    147: ("<HHB","Set beep, frequency %i, length %i, effect %i"),
+    148: ("<BHB","Pause for button 0x%X, timeout %i s, timeout_bevavior %i"),
+    149: (parseDisplayMessageAction, "Display message, options 0x%X at %i,%i timeout %i s: %s"),
+    150: ("<BB","Set build percent %i%%, ignore %i"),
+    151: ("<B","Queue song %i"),
+    152: ("<B","Reset to factory, options 0x%X"),
+    153: (parseBuildStartNotificationAction, "Start build, steps %i: %s"),
+    154: ("<B","End build, flags 0x%X"),
+    155: ("<iiiiiIBfh","Move to (%i,%i,%i,%i,%i) dda_rate: %i (relative: %X) distance: %f feedrateX64: %i"),
+    156: ("<B","Set acceleration to %i"),
+}
+
+def parseNextCommand():
+    """Parse and handle the next command.  Returns
+    True for success, False on EOF, and raises an
+    exception on corrupt data."""
+    global s3gFile
+    commandStr = s3gFile.read(1)
+    if len(commandStr) == 0:
+        #print "EOF"
+        return False
+    #sys.stdout.write(str(lineNumber) + ': ')
+    (command) = struct.unpack("B",commandStr)
+    (parse, disp) = commandTable[command[0]]
+    if type(parse) == type(""):
+        packetLen = struct.calcsize(parse)
+        packetData = s3gFile.read(packetLen)
+        if len(packetData) != packetLen:
+            raise "Packet incomplete"
+        parsed = struct.unpack(parse,packetData)
+    else:
+        parsed = parse()
+    if type(disp) != type(""):
+        disp(parsed)
+    return True
+
+s3gFile = open(sys.argv[1],'rb')
+lineNumber = 0
+while parseNextCommand():
+    lineNumber  = lineNumber + 1
+for i in faceList:
+    print "f %i %i" % (i - 1 + 1, i + 1)