motionTraceCmd.py

#-
# ==========================================================================
# Copyright (C) 1995 - 2006 Autodesk, Inc. and/or its licensors.  All 
# rights reserved.
#
# The coded instructions, statements, computer programs, and/or related 
# material (collectively the "Data") in these files contain unpublished 
# information proprietary to Autodesk, Inc. ("Autodesk") and/or its 
# licensors, which is protected by U.S. and Canadian federal copyright 
# law and by international treaties.
#
# The Data is provided for use exclusively by You. You have the right 
# to use, modify, and incorporate this Data into other products for 
# purposes authorized by the Autodesk software license agreement, 
# without fee.
#
# The copyright notices in the Software and this entire statement, 
# including the above license grant, this restriction and the 
# following disclaimer, must be included in all copies of the 
# Software, in whole or in part, and all derivative works of 
# the Software, unless such copies or derivative works are solely 
# in the form of machine-executable object code generated by a 
# source language processor.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND. 
# AUTODESK DOES NOT MAKE AND HEREBY DISCLAIMS ANY EXPRESS OR IMPLIED 
# WARRANTIES INCLUDING, BUT NOT LIMITED TO, THE WARRANTIES OF 
# NON-INFRINGEMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR 
# PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE, OR 
# TRADE PRACTICE. IN NO EVENT WILL AUTODESK AND/OR ITS LICENSORS 
# BE LIABLE FOR ANY LOST REVENUES, DATA, OR PROFITS, OR SPECIAL, 
# DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES, EVEN IF AUTODESK 
# AND/OR ITS LICENSORS HAS BEEN ADVISED OF THE POSSIBILITY 
# OR PROBABILITY OF SUCH DAMAGES.
#
# ==========================================================================
#+

#
#       Creation Date:   27 September 2006
#
#       Description:
#
#               Traces the position of an animated object
#               and create a curve showing the object's path.
#
#       Usage:
#
#               Animate an object.
#               Select the object.
#               Run the command in the command window.
#               See the object's path drawn as a curve.
#
#       Options:
#
#               s=<frame>               The start frame.  Default to 1.
#               e=<frame>               The end frame.  Default to 60.
#               b=<frame>               The by frame.  Default to 1.
#
#       Example:
#
#               From Python:
#                       import maya
#                       maya.cmds.spMotionTrace(s=1, e=100, b=2)
#
#               From Mel:
#                       spMotionTrace -s 1 -e 100 -b 2
#

import maya.OpenMaya as OpenMaya
import maya.OpenMayaMPx as OpenMayaMPx
import math, sys

kPluginCmdName="spMotionTrace"

kStartFlag = "-s"
kStartLongFlag = "-startFrame"
kEndFlag = "-e"
kEndLongFlag = "-endFrame"
kByFlag = "-b"
kByLongFlag = "-byFrame"

# command
class motionTrace(OpenMayaMPx.MPxCommand):
        def __init__(self):
                OpenMayaMPx.MPxCommand.__init__(self)
                # setup private data members
                self.__start = 1
                self.__end = 60
                self.__by = 1


        def doIt(self, args):
                """
                This method is called from script when this command is called.
                It should set up any class data necessary for redo/undo,
                parse any given arguments, and then call redoIt.
                """
                argData = OpenMaya.MArgDatabase(self.syntax(), args)

                if argData.isFlagSet(kStartFlag):
                        self.__start = argData.flagArgumentInt(kStartFlag, 0)
                if argData.isFlagSet(kEndFlag):
                        self.__end = argData.flagArgumentInt(kEndFlag, 0)
                if argData.isFlagSet(kByFlag):
                        self.__by = argData.flagArgumentInt(kByFlag, 0)

                self.redoIt()


        def redoIt(self):
                """
                This method performs the action of the command.
                This method iterates over all selected items and
                prints out connected plug and dependency node type
                information.
                """
                picked = OpenMaya.MObjectArray()
                dependNode = OpenMaya.MObject()     # Selected dependency node

                # Create a selection list iterator
                slist = OpenMaya.MSelectionList()
                OpenMaya.MGlobal.getActiveSelectionList(slist)
                iter = OpenMaya.MItSelectionList(slist)

                # Iterate over all selected dependency nodes
                # and save them in a list
                while not iter.isDone():
                        # Get the selected dependency node
                        iter.getDependNode(dependNode)
                        picked.append(dependNode)
                        iter.next()

                # sample the animation using start, end, by values
                pointArrays = [ OpenMaya.MPointArray() for i in range(picked.length()) ]

                time = self.__start
                while (time <= self.__end):
                        timeval = OpenMaya.MTime(time)
                        OpenMaya.MGlobal.viewFrame(timeval)

                        # Iterate over selected dependency nodes
                        for i in range(picked.length()):
                                # Get the selected dependency node
                                dependNode = picked[i]

                                # Create a function set for the dependency node
                                fnDependNode = OpenMaya.MFnDependencyNode(dependNode)

                                # Get the translation attribute values
                                txAttr = fnDependNode.attribute("translateX")
                                txPlug = OpenMaya.MPlug(dependNode, txAttr)
                                tx = txPlug.asDouble()

                                tyAttr = fnDependNode.attribute("translateY")
                                tyPlug = OpenMaya.MPlug(dependNode, tyAttr)
                                ty = tyPlug.asDouble()

                                tzAttr = fnDependNode.attribute("translateZ")
                                tzPlug = OpenMaya.MPlug(dependNode, tzAttr)
                                tz = tzPlug.asDouble()

                                print "adding", tx, ty, tz, "\n"
                                pointArrays[i].append(OpenMaya.MPoint(tx, ty, tz))

                        time += self.__by

                # make a path curve for each selected object
                for i in range(picked.length()):
                        self.__jMakeCurve(pointArrays[i])


        def __jMakeCurve(self, cvs):
                """
                Make a degree 1 curve from the given CVs.
                
                Note that in Python, a double underscore in front of a member name
                make the method "private" to the class through name-mangling
                """
                deg = 1
                knots = OpenMaya.MDoubleArray()

                for i in range(cvs.length()):
                        knots.append(i)

                # Now create the curve
                nullObj = OpenMaya.MObject()
                curveFn = OpenMaya.MFnNurbsCurve()
                curveFn.create(cvs, knots, deg, OpenMaya.MFnNurbsCurve.kOpen, False, False, nullObj)


# Creator
def cmdCreator():
        return OpenMayaMPx.asMPxPtr(motionTrace())


# Syntax creator
def syntaxCreator():
        syntax = OpenMaya.MSyntax()
        syntax.addFlag(kStartFlag, kStartLongFlag, OpenMaya.MSyntax.kLong)
        syntax.addFlag(kEndFlag, kEndLongFlag, OpenMaya.MSyntax.kLong)
        syntax.addFlag(kByFlag, kByLongFlag, OpenMaya.MSyntax.kLong)
        return syntax


# Initialize the script plug-in
def initializePlugin(mobject):
        mplugin = OpenMayaMPx.MFnPlugin(mobject, "Autodesk", "1.0", "Any")
        try:
                mplugin.registerCommand(kPluginCmdName, cmdCreator, syntaxCreator)
        except:
                sys.stderr.write("Failed to register command: %s\n" % kPluginCmdName)
                raise


# Uninitialize the script plug-in
def uninitializePlugin(mobject):
        mplugin = OpenMayaMPx.MFnPlugin(mobject)
        try:
                mplugin.deregisterCommand(kPluginCmdName)
        except:
                sys.stderr.write("Failed to unregister command: %s\n" % kPluginCmdName)
                raise