This reference page is linked to from the following overview topics: Maya Python API を使用する.

Detailed Description

Utility class for working with pointers and references in Python.

Many of Maya's API methods require that one or more of their parameters be passed as pointers or references. Their return values, too, can be pointers or references.

In Python parameters of class types are passed by reference but parameters of simple types, like integers and floats, are passed by value, making it impossible to call those API methods from Python. The MScriptUtil class bridges this gap by providing methods which return pointers to values of simple types and which can extract values from such pointers. These pointers can also be used wherever an API method requires a reference to a simple type or an array of a simple type.

For example, MTransformationMatrix::setShear() requires as its first parameter an array of three values of simple type 'double'. To call setShear() from Python requires using MScriptUtil to create the array of doubles:

  matrix = maya.OpenMaya.MTransformationMatrix()
  util = maya.OpenMaya.MScriptUtil()
  util.createFromDouble(1.0, 2.0, 3.0)
  ptr = util.asDoublePtr()
  m.setShear(ptr, maya.OpenMaya.MSpace.kObject)

Similar code is required to get the shear value using MTransformationMatrix::getShear(), but MScriptUtil methods must also be used to extract the returned values from the array:

  util = maya.OpenMaya.MScriptUtil()
  util.createFromDouble(0.0, 0.0, 0.0)
  ptr = util.asDoublePtr()
  matrix.getShear(ptr, maya.OpenMaya.MSpace.kObject)

  shearX = util.getDoubleArrayItem(ptr, 0)
  shearY = util.getDoubleArrayItem(ptr, 1)
  shearZ = util.getDoubleArrayItem(ptr, 2)

If a method requires a reference or pointer to an enumerated value, use a pointer to a short int instead.

An MScriptUtil object keeps two sets of values internally: its initial values, and its working values. The initial values are those supplied either in the constructor or by calling one of the object's create*() methods. The working values are those to which the as*Ptr() methods return pointers.

Each time a create*() method is called it completely replaces the old initial values with the new ones. The as*() methods (asInt(), asFloat(), etc) but not the as*Ptr() methods, all return the first internal value, converted to the appropriate type.

Each time an as*Ptr() method is called it completely replaces the old working values with new ones of the requested type and initializes them from the initial values. If the type of the working values does not match that of the initial values then appropriate conversions are done. For example, if you have initialized an MScriptUtil object with four doubles via a call to createFromDouble(), then a subsequent call to asBoolPtr() will allocate space for four boolean working values and initialize them from the initial values by converting non-zero values to true and zero values to false.

The separation of initial and working values means that changes to the working values will not affect the initial values. For example, if you pass the pointer returned by asBoolPtr() to an API method which changes the working value it points to, the object's initial value will remain unchanged and its asInt() method will continue to return the same value as it did before the API call.

The number of working values returned by the as*Ptr() methods will match the number of initial values. Thus it is important that you provide a sufficient number of initial values before calling an as*Ptr() method. If no initial values are provided in the MScriptUtil constructor and none are subsequently supplied by calls to the create*() methods, then the pointers returned by the as*Ptr() methods won't have room to store even a single value, which will likely lead to errors.

As already noted, each call to one of an object's as*Ptr() methods completely replaces the old working values with new ones, thus rendering invalid any pointers previously returned by that object. This means that if you need multiple pointers for a single API call, you will need multiple MScriptUtil objects. MFnMesh::getUV() provides an example of this:

  meshFn = maya.OpenMaya.MFnMesh(node)

  u_util = maya.OpenMaya.MScriptUtil(0.0)
  u_ptr = u_util.asFloatPtr()
  v_util = maya.OpenMaya.MScriptUtil(0.0)
  v_ptr = v_util.asFloatPtr()

  meshFn.getUV(0, u_ptr, v_ptr)

  u = u_util.getFloat(u_ptr)
  v = v_util.getFloat(v_ptr)

When an MScriptUtil object is destroyed any pointers to its data immediately become invalid. Thus the following code will fail because the MScriptUtil objects created by getUVPtrs() will go out of scope and be destroyed when the function returns, rendering the pointers it returns invalid:

  # WRONG!
  def getUVPtrs():
      u_util = maya.OpenMaya.MScriptUtil(0.0)
      u_ptr = u_util.asFloatPtr()
      v_util = maya.OpenMaya.MScriptUtil(0.0)
      v_ptr = v_util.asFloatPtr()
      return [u_ptr, v_ptr]

  uvPtrs = getUVPtrs()
  meshFn.getUV(0, uvPtrs[0], uvPtrs[1])

To work, getUVPtrs() would have to preserve the MScriptUtil objects in some way, such as passing them back to the caller as well:

  # RIGHT!
  def getUVPtrs():
      u_util = maya.OpenMaya.MScriptUtil(0.0)
      u_ptr = u_util.asFloatPtr()
      v_util = maya.OpenMaya.MScriptUtil(0.0)
      v_ptr = v_util.asFloatPtr()
      return [(u_ptr, u_util), (v_ptr, v_util)]

  uvPtrs = getUVPtrs()
  meshFn.getUV(0, uvPtrs[0][0], uvPtrs[1][0])

This class is admittedly cumbersome to use but it provides a way of building parameters and accessing return values for methods which would not otherwise be accessible from Python.

#include <MScriptUtil.h>

List of all members.

Public Member Functions
	MScriptUtil ()
	Default constructor.
	~MScriptUtil ()
	Destructor.
	MScriptUtil (int value)
	Instantiate class with an int reference.
	MScriptUtil (short value)
	Instantiate class with an short reference.
	MScriptUtil (float value)
	Instantiate class with an float reference.
	MScriptUtil (double value)
	Instantiate class with an double reference.
	MScriptUtil (unsigned int value)
	Instantiate class with an unsigned int reference.
	MScriptUtil (bool value)
	Instantiate class with an bool reference.
	MScriptUtil (const MIntArray &array)
	Instantiate class with an integer array.
	MScriptUtil (const MDoubleArray &array)
	Instantiate class with an double array.
	MScriptUtil (const MUintArray &array)
	Instantiate class with an unsigned integer array.
	MScriptUtil (const MUint64Array &array)
	Instantiate class with an unsigned integer array.
void	createFromInt (int x, int y=0, int z=0, int w=0)
	Create this object from 4 integers.
void	createFromDouble (double x, double y=0, double z=0, double w=0)
	Create this object from 4 doubles.
bool	createFromList (void *pythonList, unsigned int length)
	Create this object with a python list and length.
int	asInt ()
	Return the first item added to this object as an integer. Search for all occurrences
short	asShort ()
	Return the first item added to this object as a short. Search for all occurrences
float	asFloat ()
	Return the first item added to this object as a float. Search for all occurrences
double	asDouble ()
	Return the first item added to this object as a double. Search for all occurrences
unsigned int	asUint ()
	Return the first item added to this object as a unsigned integer. Search for all occurrences
bool	asBool ()
	Return the first item added to this object as a bool.
int *	asIntPtr ()
	Return an integer pointer to the data of this class.
short *	asShortPtr ()
	Return a short pointer to the data of this class.
float *	asFloatPtr ()
	Return a float pointer to the data of this class.
double *	asDoublePtr ()
	Return a double pointer to the data of this class.
unsigned int *	asUintPtr ()
	Return an unsigned integer pointer to the data of this class.
bool *	asBoolPtr ()
	Return a bool pointer to the data of this class.
char *	asCharPtr ()
	Return a char pointer to the data of this class.
unsigned char *	asUcharPtr ()
	Return a unsigned char pointer to the data of this class.
Mint2 *	asInt2Ptr ()
	Copy the data to a temporary array of the right type and return its address.
Mint3 *	asInt3Ptr ()
	Copy the data to a temporary array of the right type and return its address.
Mint4 *	asInt4Ptr ()
	Copy the data to a temporary array of the right type and return its address.
Mshort2 *	asShort2Ptr ()
	Copy the data to a temporary array of the right type and return its address.
Mshort3 *	asShort3Ptr ()
	Copy the data to a temporary array of the right type and return its address.
Mshort4 *	asShort4Ptr ()
	Copy the data to a temporary array of the right type and return its address.
Mfloat2 *	asFloat2Ptr ()
	Copy the data to a temporary array of the right type and return its address.
Mfloat3 *	asFloat3Ptr ()
	Copy the data to a temporary array of the right type and return its address.
Mfloat4 *	asFloat4Ptr ()
	Copy the data to a temporary array of the right type and return its address.
Mdouble2 *	asDouble2Ptr ()
	Copy the data to a temporary array of the right type and return its address.
Mdouble3 *	asDouble3Ptr ()
	Copy the data to a temporary array of the right type and return its address.
Mdouble4 *	asDouble4Ptr ()
	Copy the data to a temporary array of the right type and return its address.
Muint2 *	asUint2Ptr ()
	Copy the data to a temporary array of the right type and return its address.
Muint3 *	asUint3Ptr ()
	Copy the data to a temporary array of the right type and return its address.
Muint4 *	asUint4Ptr ()
	Copy the data to a temporary array of the right type and return its address.
Static Public Member Functions
static void	setInt (int &var, int value)
	Set an integer reference value.
static void	setShort (short &var, int value)
	Set a short reference value.
static void	setFloat (float &var, double value)
	Set a float reference value.
static void	setDouble (double &var, double value)
	Set a double reference value.
static void	setUint (unsigned int &var, int value)
	Set an unsigned integer reference value.
static void	setBool (bool &var, int value)
	Set a bool reference value.
static void	setChar (char &var, int value)
	Set a char reference value.
static void	setUchar (unsigned char &var, int value)
	Set an unsigned char reference value.
static int	getInt (int &var)
	Get the value of an integer reference.
static int	getShort (short &var)
	Get the value of a short reference.
static double	getFloat (float &var)
	Get the values of a float reference.
static double	getDouble (double &var)
	Get the value of a double reference.
static int	getUint (unsigned int &var)
	Get the value of an unsigned int reference.
static int	getBool (bool &var)
	Get the value of a bool reference.
static int	getChar (char &var)
	Get the value of a char reference.
static int	getUchar (unsigned char &var)
	Get the value of an unsigned char reference.
static bool	setIntArray (int *var, unsigned int index, int value)
	Set an integer value in an array.
static bool	setShortArray (short *var, unsigned int index, int value)
	Set a short value in an array.
static bool	setFloatArray (float *var, unsigned int index, double value)
	Set a float value in an array.
static bool	setDoubleArray (double *var, unsigned int index, double value)
	Set a double value in an array.
static bool	setUintArray (unsigned int *var, unsigned int index, int value)
	Set an unsigned integer value in an array.
static bool	setBoolArray (bool *var, unsigned int index, int value)
	Set a bool value in an array.
static bool	setCharArray (char *var, unsigned int index, int value)
	Set a char value in an array.
static bool	setUcharArray (unsigned char *var, unsigned int index, int value)
	Set an unsigned char value in an array.
static int	getIntArrayItem (int *var, unsigned int index)
	Get a int value from an array.
static int	getShortArrayItem (short *var, unsigned int index)
	Get a short value from an array.
static double	getFloatArrayItem (float *var, unsigned int index)
	Get a float value from an array.
static double	getDoubleArrayItem (double *var, unsigned int index)
	Get a double value from an array.
static int	getUintArrayItem (unsigned int *var, unsigned int index)
	Get an unsigned value from an array.
static int	getBoolArrayItem (bool *var, unsigned int index)
	Get a bool value from an array.
static int	getCharArrayItem (char *var, unsigned int index)
	Get a char value from an array.
static int	getUcharArrayItem (unsigned char *var, unsigned int index)
	Get an unsigned char value from an array.
static bool	createMatrixFromList (void *pythonList, MMatrix &matrix)
	Create an MMatrix object from a list of 16 doubles.
static bool	createFloatMatrixFromList (void *pythonList, MFloatMatrix &matrix)
	Create an MFloatMatrix object from a list of 16 doubles.
static bool	createIntArrayFromList (void *pythonList, MIntArray &array)
	Create an MIntArray object from a python list.
static bool	createFloatArrayFromList (void *pythonList, MFloatArray &array)
	Create an MFloatArray object from a python list.
static int	getInt2ArrayItem (int(*var)[2], unsigned int r, unsigned int c)
	Get a value from the two dimensional array.
static bool	setInt2ArrayItem (int(*var)[2], unsigned int r, unsigned int c, int value)
	Set a value in the two dimensional array.
static int	getInt3ArrayItem (int(*var)[3], unsigned int r, unsigned int c)
	Get a value from the three dimensional array.
static bool	setInt3ArrayItem (int(*var)[3], unsigned int r, unsigned int c, int value)
	Set a value in the three dimensional array.
static int	getInt4ArrayItem (int(*var)[4], unsigned int r, unsigned int c)
	Get a value from the four dimensional array.
static bool	setInt4ArrayItem (int(*var)[4], unsigned int r, unsigned int c, int value)
	Set a value in the four dimensional array.
static short	getShort2ArrayItem (short(*var)[2], unsigned int r, unsigned int c)
	Get a value from the two dimensional array.
static bool	setShort2ArrayItem (short(*var)[2], unsigned int r, unsigned int c, short value)
	Set a value in the two dimensional array.
static short	getShort3ArrayItem (short(*var)[3], unsigned int r, unsigned int c)
	Get a value from the three dimensional array.
static bool	setShort3ArrayItem (short(*var)[3], unsigned int r, unsigned int c, short value)
	Set a value in the three dimensional array.
static short	getShort4ArrayItem (short(*var)[4], unsigned int r, unsigned int c)
	Get a value from the four dimensional array.
static bool	setShort4ArrayItem (short(*var)[4], unsigned int r, unsigned int c, short value)
	Set a value in the two dimensional array.
static float	getFloat2ArrayItem (float(*var)[2], unsigned int r, unsigned int c)
	Get a value from the two dimensional array.
static bool	setFloat2ArrayItem (float(*var)[2], unsigned int r, unsigned int c, float value)
	Set a value in the two dimensional array.
static float	getFloat3ArrayItem (float(*var)[3], unsigned int r, unsigned int c)
	Get a value from the three dimensional array.
static bool	setFloat3ArrayItem (float(*var)[3], unsigned int r, unsigned int c, float value)
	Set a value in the three dimensional array.
static float	getFloat4ArrayItem (float(*var)[4], unsigned int r, unsigned int c)
	Get a value from the four dimensional array.
static bool	setFloat4ArrayItem (float(*var)[4], unsigned int r, unsigned int c, float value)
	Set a value in the four dimensional array.
static double	getDouble2ArrayItem (double(*var)[2], unsigned int r, unsigned int c)
	Get a value from the two dimensional array.
static bool	setDouble2ArrayItem (double(*var)[2], unsigned int r, unsigned int c, double value)
	Set a value in the two dimensional array.
static double	getDouble3ArrayItem (double(*var)[3], unsigned int r, unsigned int c)
	Get a value from the three dimensional array.
static bool	setDouble3ArrayItem (double(*var)[3], unsigned int r, unsigned int c, double value)
	Set a value in the three dimensional array.
static double	getDouble4ArrayItem (double(*var)[4], unsigned int r, unsigned int c)
	Get a value from the four dimensional array.
static bool	setDouble4ArrayItem (double(*var)[4], unsigned int r, unsigned int c, double value)
	Set a value in the four dimensional array.
static unsigned int	getUint2ArrayItem (unsigned int(*var)[2], unsigned int r, unsigned int c)
	Get a value from the two dimensional array.
static bool	setUint2ArrayItem (unsigned int(*var)[2], unsigned int r, unsigned int c, unsigned int value)
	Set a value in the two dimensional array.
static unsigned int	getUint3ArrayItem (unsigned int(*var)[3], unsigned int r, unsigned int c)
	Get a value from the three dimensional array.
static bool	setUint3ArrayItem (unsigned int(*var)[3], unsigned int r, unsigned int c, unsigned int value)
	Set a value in the three dimensional array.
static unsigned int	getUint4ArrayItem (unsigned int(*var)[4], unsigned int r, unsigned int c)
	Get a value from the four dimensional array.
static bool	setUint4ArrayItem (unsigned int(*var)[4], unsigned int r, unsigned int c, unsigned int value)
	Set a value in the four dimensional array. Search for all occurrences

Constructor & Destructor Documentation

MScriptUtil ( )

Default constructor.

The instance is set to contain no elements.

MScriptUtil ( int value )

Instantiate class with an int reference.

Parameters: