公司来了位在autodesk工作十年的大神，最近给我们培训maya API这块儿的东西，感觉学到不少东西，这是第二节课，她给我们布置的作业是写个带flag的command，具体说就是用api获取选择物体的dagpath，并且添加个flag——verbos，如果有这个flag的话，那么就打出这个物体的inclusiveMatrix和exclusiveMatrix，自己用python API写了一下，又用C++写了下，最后C++在打印矩阵的格式时不是很理想，等以后有时间再完善之，下面分别是二者的代码。
Python
import sys
import maya.api.OpenMaya as om
def maya_useNewAPI(): pass
class DagInfoCommand(om.MPxCommand):
commandName = 'dagInfo'
verbosFlag = '-v'
verbosFlagLong = '-verbos'
helpFlag = '-h'
helpFlagLong = '-help'
helpText = '\nThe dagInfo command is used to get dag node path and matrix\n'
def __init__(self):
om.MPxCommand.__init__(self)
@staticmethod
def creator():
return DagInfoCommand()
def doIt(self, args):
try:
argDatabase = om.MArgDatabase(self.syntax(), args)
except RuntimeError:
om.MGlobal.displayError('Error while parsing arguments:\n#\t# If passing in list of nodes, also check that node names exist in scene.')
raise
help = argDatabase.isFlagSet(DagInfoCommand.helpFlag)
if help:
self.setResult(DagInfoCommand.helpText)
return
activeObjects = om.MGlobal.getActiveSelectionList()
iterObjects = om.MItSelectionList(activeObjects)
verbos = argDatabase.isFlagSet(DagInfoCommand.verbosFlag)
while not iterObjects.isDone():
path = iterObjects.getDagPath()
fullPath = path.fullPathName()
partialPath = path.partialPathName()
num = path.length()
parent = path.pop()
print '>>> fullPath', fullPath
print '>>> partialPath', partialPath
print '>>> num', num
print '>>> parent', parent
if verbos:
inclusiveMatrix = path.inclusiveMatrix()
exclusiveMatrix = path.exclusiveMatrix()
print '>>> inclusive matrix', inclusiveMatrix
print '>>> exclusiveMatrix', exclusiveMatrix
iterObjects.next()
@staticmethod
def createSyntax():
syntax = om.MSyntax()
syntax.addFlag(DagInfoCommand.verbosFlag, DagInfoCommand.verbosFlagLong)
syntax.addFlag(DagInfoCommand.helpFlag, DagInfoCommand.helpFlagLong)
return syntax
def initializePlugin(mobject):
pluginFn = om.MFnPlugin(mobject, 'Lulongfei', '1.0', 'Any')
try:
pluginFn.registerCommand(DagInfoCommand.commandName, DagInfoCommand.creator, DagInfoCommand.createSyntax)
except:
sys.stderr.write('Failed to register command %s'%DagInfoCommand.commandName)
raise
def uninitializePlugin(mobject):
pluginFn = om.MFnPlugin(mobject)
try:
pluginFn.deregisterCommand(DagInfoCommand.commandName)
except:
sys.stderr.write('Failed to deregister command %s'%DagInfoCommand.commandName)
raiseC++
dagInfoCmd.h
#ifndef _DAGINFO_CMD_
#define _DAGINFO_CMD_
#include <maya/MSyntax.h>
#include <maya/MArgDatabase.h>
#include <maya/MGlobal.h>
#include <maya/MSelectionList.h>
#include <maya/MItSelectionList.h>
#include <maya/MDagPath.h>
#include <maya/MPxCommand.h>
class DagInfoCmd: public MPxCommand
{
public:
DagInfoCmd();
virtual ~DagInfoCmd();
virtual MStatus doIt(const MArgList&);
static void *creator(){return new DagInfoCmd(); }
static MSyntax newSyntax();
void printMayaMatrix(const MMatrix &mat);
};
#endifdagInfoCmd.cpp
#include "DagInfoCmd.h"
#include <maya/MMatrix.h>
#include <maya/MArgList.h>
#include <maya/MFnPlugin.h>
using namespace std;
static const char *verbosFlag = "-v", *verbosLongFlag = "-verbos";
static const char *helpFlag = "-h", *helpLongFlag = "-help";
static const char *helpText = "\nThe dagInfo command is used to get dag node path and matrix\n";
DagInfoCmd::DagInfoCmd(){}
DagInfoCmd::~DagInfoCmd(){}
MSyntax DagInfoCmd::newSyntax(){
MSyntax *syntaxPtr = new MSyntax();
syntaxPtr -> addFlag(verbosFlag, verbosLongFlag);
syntaxPtr -> addFlag(helpFlag, helpLongFlag);
return *syntaxPtr;
}
void DagInfoCmd::printMayaMatrix(const MMatrix&mat)
{
char *buf = new char[128];
sprintf(buf, "(%4.4f %4.4f %4.4f %4.4f)", mat[0][0], mat[0][1], mat[0][2], mat[0][3]);
MGlobal::displayInfo(buf);
sprintf(buf, "(%4.4f %4.4f %4.4f %4.4f)", mat[1][0], mat[1][1], mat[1][2], mat[1][3]);
MGlobal::displayInfo(buf);
sprintf(buf, "(%4.4f %4.4f %4.4f %4.4f)", mat[2][0], mat[2][1], mat[2][2], mat[2][3]);
MGlobal::displayInfo(buf);
sprintf(buf, "(%4.4f %4.4f %4.4f %4.4f)", mat[3][0], mat[3][1], mat[3][2], mat[3][3]);
MGlobal::displayInfo(buf);
delete [] buf;
}
MStatus DagInfoCmd::doIt(const MArgList &args)
{
MStatus stat;
MArgDatabase *argData = new MArgDatabase(syntax(), args, &stat);
if( !stat )
return stat;
if( argData -> isFlagSet(helpFlag))
{
setResult(helpText);
return MS::kSuccess;
}
unsigned verbos = argData -> isFlagSet(verbosFlag);
MSelectionList activeObjects;
MGlobal::getActiveSelectionList(activeObjects);
MItSelectionList iterObjects(activeObjects);
for(; !iterObjects.isDone(); iterObjects.next())
{
MDagPath path;
iterObjects.getDagPath(path);
MString fullPath = path.fullPathName(&stat);
CHECK_MSTATUS_AND_RETURN_IT(stat);
MString partialPath = path.partialPathName(&stat);
CHECK_MSTATUS_AND_RETURN_IT(stat);
MGlobal::displayInfo(fullPath);
MGlobal::displayInfo(partialPath);
if(verbos){
MMatrix inMat = path.inclusiveMatrix();
MMatrix exMat = path.exclusiveMatrix();
printMayaMatrix(inMat);
printMayaMatrix(exMat);
}
}
return MS::kSuccess;
}
MStatus initializePlugin(MObject mobject)
{
MFnPlugin plugin(mobject, "lulongfei", "1.0");
MStatus stat;
stat = plugin.registerCommand("dagInfo", DagInfoCmd::creator, DagInfoCmd::newSyntax);
if (!stat)
stat.perror("registerCommand failed!");
return stat;
}
MStatus uninitializePlugin(MObject mobject)
{
MFnPlugin plugin(mobject);
MStatus stat;
stat = plugin.deregisterCommand("dagInfo");
if (!stat)
stat.perror("deregisterCommand failed!");
return stat;
}总结：
- 在python里creator和createSyntax必须是静态方法，切记。
- MDagPath有些很重要的方法，如length，depth， pop等。
- MGlobal、MSelectionList、MItSelectionList等等这些helper classes，一些常用的方法要知道。
整体感觉比以前对mayaAPI认识又上了个一个小台阶，而且写起来更加快了，基本可以说是一次成型，下面附一张最后运行的结果。
