Other Commands#

This page documents utility commands that do not fit into the solve or image categories. They cover reprojection, animation-curve analysis and filtering, geometry fitting, colour-space queries, and memory statistics.

`mmReprojection` Command#

mmReprojection reprojects 3D world-space points (or Maya transform nodes) into 2D screen-space coordinates for a given camera at one or more times. It is a key utility for scripting deviation calculations and for checking whether a transform lies in front of or behind the camera.

Flags#

Command Flag	Command Flag (short)	Type	Description	Default Value
-worldPoint	-wp	double, double, double	A world-space XYZ point to reproject instead of supplying a node.	None
-camera	-c	string, string	Camera transform and shape nodes.	None
-time	-t	double (multi-use)	Frame time(s) at which to evaluate. Can be given multiple times.	None
-imageResolution	-ir	double, double	Image width and height in pixels, used for pixel-coordinate output.	2048, 2048
-asCameraPoint	-cpt	bool	Return position in camera space (X, Y, Z).	False
-asWorldPoint	-wpt	bool	Return position in world space (X, Y, Z).	False
-asCoordinate	-cd	bool	Return as film-back coordinate (0–1 range on each axis).	False
-asNormalizedCoordinate	-ncd	bool	Return as normalised coordinate (−0.5 to 0.5 on the short axis).	False
-asMarkerCoordinate	-mcd	bool	Return as mmSolver marker coordinate (same range as normalised, used by the solver).	False
-asPixelCoordinate	-pcd	bool	Return as pixel coordinate based on `-imageResolution`.	False
-withCameraDirectionRatio	-wcd	bool	Append a camera-direction ratio value; negative means the point is behind the camera.	False
-distortMode	-dsm	unsigned int	Apply lens distortion: 0 = none, 1 = distort, 2 = undistort. Requires an `outLens` connection on the camera shape.	0 (none)

Return#

Returns a flat list of doubles. For each input point and each requested time the values for every requested output type are appended in order. For example, if -asCoordinate is requested for two frames the result is [u0, v0, u1, v1].

Example#

Python Example:

import maya.cmds

# Reproject a bundle node at frames 1, 12 and 24 as marker coordinates.
result = maya.cmds.mmReprojection(
    'myBundle',
    camera=('camera1', 'cameraShape1'),
    time=(1, 12, 24),
    asMarkerCoordinate=True,
)
# result is [u1, v1, u12, v12, u24, v24]

# Reproject a raw world-space point, returning pixel coordinates.
result = maya.cmds.mmReprojection(
    worldPoint=(10.0, 5.0, -3.0),
    camera=('camera1', 'cameraShape1'),
    time=(1,),
    imageResolution=(1920, 1080),
    asPixelCoordinate=True,
)

MEL Example:

mmReprojection myBundle
    -camera "camera1" "cameraShape1"
    -time 1
    -time 12
    -asMarkerCoordinate true;

`mmAnimCurveStatistics` Command#

mmAnimCurveStatistics computes statistical measures over the keyframe values of one or more animation curves within an optional frame range. It can also operate on raw lists of X/Y values instead of curve nodes.

Flags#

Command Flag	Command Flag (short)	Type	Description	Default Value
-startFrame	-sf	unsigned	First frame of the evaluation range.	(all keys)
-endFrame	-ef	unsigned	Last frame of the evaluation range.	(all keys)
-mean	-m	bool	Calculate and return the mean (average) value.	False
-median	-md	bool	Calculate and return the median value.	False
-populationVariance	-pvr	bool	Calculate and return the population variance.	False
-populationStandardDeviation	-psd	bool	Calculate and return the population standard deviation.	False
-signalToNoiseRatio	-snr	bool	Calculate and return the signal-to-noise ratio.	False
-xValues	-xv	double	(multi-use) Provide raw X (time) values instead of a curve node.	None
-yValues	-yv	double	(multi-use) Provide raw Y (value) values instead of a curve node.	None

Return#

Returns a flat list of doubles. Each requested statistic contributes two values to the list: a type identifier followed by the computed value. The type identifiers are: 0 = mean, 1 = median, 2 = population variance, 3 = population standard deviation, 4 = signal-to-noise ratio.

Example#

Python Example:

import maya.cmds

# Compute mean and standard deviation of an animation curve.
result = maya.cmds.mmAnimCurveStatistics(
    'myAnimCurve',
    startFrame=1,
    endFrame=100,
    mean=True,
    populationStandardDeviation=True,
)
# result: [0.0, <mean_value>, 3.0, <std_dev_value>]

MEL Example:

mmAnimCurveStatistics myAnimCurve
    -startFrame 1
    -endFrame 100
    -mean true
    -populationStandardDeviation true;

`mmAnimCurveDiffStatistics` Command#

mmAnimCurveDiffStatistics computes difference-based statistical measures between two animation curves (or two sets of raw values) over an optional frame range. It is useful for quantifying how closely a solved curve matches a reference.

Flags#

Command Flag	Command Flag (short)	Type	Description	Default Value
-startFrame	-sf	unsigned	First frame of the evaluation range.	(all keys)
-endFrame	-ef	unsigned	Last frame of the evaluation range.	(all keys)
-meanAbsoluteDifference	-mad	bool	Return the mean absolute difference between the two curves.	False
-rootMeanSquareDifference	-rsd	bool	Return the root-mean-square difference.	False
-meanDifference	-mnf	bool	Return the mean signed difference.	False
-medianDifference	-mdf	bool	Return the median signed difference.	False
-populationVariance	-pvr	bool	Return the population variance of the differences.	False
-populationStandardDeviation	-psd	bool	Return the population standard deviation of the differences.	False
-peakToPeak	-ptp	bool	Return the peak-to-peak (max minus min) difference.	False
-signalToNoiseRatio	-snr	bool	Return the signal-to-noise ratio.	False
-meanAbsoluteError	-mae	bool	Return the mean absolute error.	False
-rootMeanSquareError	-rme	bool	Return the root-mean-square error.	False
-normalizedRootMeanSquareError	-nse	bool	Return the normalised root-mean-square error.	False
-rSquared	-r2	bool	Return the R² (coefficient of determination).	False
-xValues	-xv	double	(multi-use) Raw X values shared by both curves.	None
-yValuesA	-yva	double	(multi-use) Raw Y values for curve A.	None
-yValuesB	-yvb	double	(multi-use) Raw Y values for curve B.	None

Return#

Returns a flat list of doubles. Each requested statistic contributes a type-identifier / value pair. Select curves are passed as the first two objects in the selection list; alternatively, supply raw values via -xValues, -yValuesA, and -yValuesB.

Example#

Python Example:

import maya.cmds

result = maya.cmds.mmAnimCurveDiffStatistics(
    'curveA', 'curveB',
    startFrame=1,
    endFrame=100,
    meanAbsoluteDifference=True,
    rootMeanSquareError=True,
)

MEL Example:

mmAnimCurveDiffStatistics curveA curveB
    -startFrame 1 -endFrame 100
    -meanAbsoluteDifference true
    -rootMeanSquareError true;

`mmAnimCurveFilterPops` Command#

mmAnimCurveFilterPops detects and removes single-frame pops (outlier keyframe values) from an animation curve. The command is undoable. When -returnResultOnly is set the curve is not modified and the detected pop frames are returned instead.

Flags#

-startFrame

-sf: unsigned First frame of the evaluation range. (all keys)

-endFrame

-ef: unsigned Last frame of the evaluation range. (all keys)

-threshold

-th: double Deviation threshold above which a keyframe is considered a pop. 1.0

-returnResultOnly

-rro: bool When true, return the affected frame numbers without modifying the curve. False

Command Flag Command Flag (short) Type Description Default Value ====================== ====================== ======== ===================================================================================== ============= -startFrame -sf unsigned First frame of the evaluation range. (all keys) -endFrame -ef unsigned Last frame of the evaluation range. (all keys) -controlPointCount -cpc unsigned Number of control points (keyframes) in the simplified curve. 0 -distribution -dtr string Distribution of control points: "uniform" or "auto_keypoints". (none) -interpolation -int string Interpolation method: "linear", "quadratic_nubs", or "cubic_nubs". (none) -returnResultOnly -rro bool When true, return the simplified key times and values without modifying the curve. False ====================== ====================== ======== ===================================================================================== =============

Return#

When -returnResultOnly is True, returns a flat list of alternating time/value pairs for the simplified keys. Otherwise modifies the curve in-place and returns nothing.

Example#

Python Example:

import maya.cmds

# Simplify a curve to 5 uniformly-distributed linear keys.
maya.cmds.mmAnimCurveSimplify(
    'myAnimCurve',
    startFrame=1,
    endFrame=100,
    controlPointCount=5,
    distribution='uniform',
    interpolation='linear',
)

# Return simplified values without modifying the curve.
result = maya.cmds.mmAnimCurveSimplify(
    'myAnimCurve',
    controlPointCount=5,
    distribution='uniform',
    interpolation='cubic_nubs',
    returnResultOnly=True,
)

MEL Example:

mmAnimCurveSimplify myAnimCurve
    -startFrame 1 -endFrame 100
    -controlPointCount 5
    -distribution "uniform"
    -interpolation "linear";

`mmBestFitPlane` Command#

mmBestFitPlane fits a plane to a set of 3D points using a least-squares method and returns the plane’s position and orientation. It is useful for establishing a ground plane or reference surface from tracked 3D bundles.

Flags#

Command Flag	Command Flag (short)	Type	Description	Default Value
-pointComponent	-pc	double	(multi-use) Flat list of XYZ components of the input points (i.e. X0, Y0, Z0, X1, Y1, Z1, …).	None
-withScale	-wsc	bool	Include a scale value in the output when using `position_direction_and_scale` output mode.	False
-outputValuesAs	-ova	string	Format of the return value: `"position_and_direction"`, `"position_direction_and_scale"`, or `"matrix_4x4"`.	`"position_and_direction"`
-outputRmsError	-ore	bool	Append the RMS fit error to the output.	True

Return#

Returns a flat list of doubles. The content depends on -outputValuesAs:

"position_and_direction": [px, py, pz, nx, ny, nz] plus optional RMS error.
"position_direction_and_scale": as above with a scale value appended before the optional RMS error.
"matrix_4x4": 16 matrix values in row-major order plus optional RMS error.

Returns None if the plane could not be fit (e.g. fewer than 3 non-collinear points).

Example#

Python Example:

import maya.cmds

nodes = maya.cmds.ls(sl=True, long=True) or []
points_flat = []
for node in nodes:
    pos = maya.cmds.xform(node, query=True, worldSpace=True, translation=True)
    points_flat.extend(pos)

result = maya.cmds.mmBestFitPlane(
    pointComponent=points_flat,
    outputValuesAs='matrix_4x4',
    outputRmsError=True,
)
if result and len(result) == 17:
    maya.cmds.xform('pPlane1', worldSpace=True, matrix=result[:16])

MEL Example:

mmBestFitPlane
    -pointComponent 0.0 0.0 0.0
    -pointComponent 1.0 0.0 0.0
    -pointComponent 0.5 1.0 0.0
    -outputValuesAs "position_and_direction"
    -outputRmsError true;

`mmMarkerHomography` Command#

mmMarkerHomography computes a 2D homography matrix from corresponding marker positions in two views (two different frames or two different cameras). It is used to warp one frame’s image into alignment with another for planar surfaces.

Flags#

Command Flag	Command Flag (short)	Type	Description	Default Value
-cameraA	-ca	string	Camera transform node for view A.	None
-cameraB	-cb	string	Camera transform node for view B.	None
-frameA	-fa	unsigned int	Frame number for view A.	1
-frameB	-fb	unsigned int	Frame number for view B.	1
-markerPair	-mp	string, string	Pair of marker node names (markerA, markerB). Can be given multiple times (minimum 4 pairs required).	None

Return#

Returns a flat list of 9 doubles representing the 3×3 homography matrix in row-major order, or None if the computation fails (e.g. insufficient or degenerate correspondences).

Example#

Python Example:

import maya.cmds

result = maya.cmds.mmMarkerHomography(
    cameraA='cameraA',
    cameraB='cameraB',
    frameA=21,
    frameB=29,
    markerPair=[
        ('markerA1', 'markerB1'),
        ('markerA2', 'markerB2'),
        ('markerA3', 'markerB3'),
        ('markerA4', 'markerB4'),
    ],
)

MEL Example:

mmMarkerHomography
    -cameraA "cameraA"
    -cameraB "cameraB"
    -frameA 21
    -frameB 29
    -markerPair "markerA1" "markerB1"
    -markerPair "markerA2" "markerB2"
    -markerPair "markerA3" "markerB3"
    -markerPair "markerA4" "markerB4";

`mmColorIO` Command#

mmColorIO exposes OpenColorIO (OCIO) colour-space information from within Maya. It can query the active OCIO configuration, list available colour spaces, guess a colour space from a file path, and look up standard OCIO role names.

Flags#

Command Flag	Command Flag (short)	Type	Description	Default Value
-colorSpaceExists	-ce	bool	Return `True` if the named colour space (given as a string argument) exists in the active config.	False
-configDescription	-de	bool	Return the description string of the active OCIO config.	False
-configName	-nm	bool	Return the name of the active OCIO config.	False
-configSearchPath	-sp	bool	Return the search paths defined in the active OCIO config.	False
-configWorkingDirectory	-wd	bool	Return the working directory of the active OCIO config.	False
-guessColorSpaceFromFile	-gc	bool	Guess the colour space for the file path supplied as a string argument.	False
-listColorSpacesActive	-la	bool	Return the list of active colour space names.	False
-listColorSpacesAll	-lc	bool	Return the list of all colour space names (active and inactive).	False
-listColorSpacesInactive	-li	bool	Return the list of inactive colour space names.	False
-roleColorPicking	-rp	bool	Return the colour space name assigned to the `color_picking` role.	False
-roleColorTiming	-rt	bool	Return the colour space name assigned to the `color_timing` role.	False
-roleCompositingLog	-rg	bool	Return the colour space name assigned to the `compositing_log` role.	False
-roleData	-ra	bool	Return the colour space name assigned to the `data` role.	False
-roleDefault	-rd	bool	Return the colour space name assigned to the `default` role.	False
-roleMattePaint	-ri	bool	Return the colour space name assigned to the `matte_paint` role.	False
-roleReference	-rr	bool	Return the colour space name assigned to the `reference` role.	False
-roleRendering	-rn	bool	Return the colour space name assigned to the `rendering` role.	False
-roleSceneLinear	-rl	bool	Return the colour space name assigned to the `scene_linear` role.	False
-roleTexturePaint	-rx	bool	Return the colour space name assigned to the `texture_paint` role.	False

Return#

Depending on the flags used, returns a string, a string array, or a boolean. Multiple flags may be combined in a single call; results are concatenated in the order the flags appear.

Example#

Python Example:

import maya.cmds

# List all colour spaces in the active config.
spaces = maya.cmds.mmColorIO(listColorSpacesAll=True)

# Get the scene-linear role name.
linear_cs = maya.cmds.mmColorIO(roleSceneLinear=True)

# Check whether a colour space exists.
exists = maya.cmds.mmColorIO('ACEScg', colorSpaceExists=True)

# Guess the colour space of a file.
cs = maya.cmds.mmColorIO(
    '/path/to/image.exr',
    guessColorSpaceFromFile=True,
)

MEL Example:

mmColorIO -listColorSpacesAll true;
mmColorIO -roleSceneLinear true;
mmColorIO -configName true;

`mmMemoryGPU` Command#

mmMemoryGPU queries GPU (VRAM) memory statistics reported by Maya’s Viewport 2.0 renderer. It operates in query mode only.

Flags#

Command Flag	Command Flag (short)	Type	Description
-total	-tot	(none)	Query total GPU memory.
-free	-fre	(none)	Query free (available) GPU memory.
-used	-usd	(none)	Query used GPU memory.
-asKiloBytes	-kb	(none)	Return the result in kilobytes.
-asMegaBytes	-mb	(none)	Return the result in megabytes.
-asGigaBytes	-gb	(none)	Return the result in gigabytes.

Note

The command requires -query mode. Exactly one of -total, -free, or -used must be given, combined with exactly one unit flag.

Return#

Returns a single double value representing the requested memory amount in the chosen unit.

Example#

Python Example:

import maya.cmds

total_mb  = maya.cmds.mmMemoryGPU(query=True, total=True,  asMegaBytes=True)
free_mb   = maya.cmds.mmMemoryGPU(query=True, free=True,   asMegaBytes=True)
used_mb   = maya.cmds.mmMemoryGPU(query=True, used=True,   asMegaBytes=True)

MEL Example:

mmMemoryGPU -query -total -asMegaBytes;
mmMemoryGPU -query -free  -asMegaBytes;
mmMemoryGPU -query -used  -asMegaBytes;

`mmMemorySystem` Command#

mmMemorySystem queries system (RAM) memory statistics, including total, free, and used physical memory as well as the memory used by the current Maya process. It operates in query mode only.

Flags#

Command Flag	Command Flag (short)	Type	Description
-systemPhysicalMemoryTotal	-tot	(none)	Query total physical (RAM) memory on the system.
-systemPhysicalMemoryFree	-fre	(none)	Query free physical memory on the system.
-systemPhysicalMemoryUsed	-usd	(none)	Query used physical memory on the system.
-processMemoryUsed	-pud	(none)	Query memory used by the current Maya process.
-asKiloBytes	-kb	(none)	Return the result in kilobytes.
-asMegaBytes	-mb	(none)	Return the result in megabytes.
-asGigaBytes	-gb	(none)	Return the result in gigabytes.

Note

The command requires -query mode. Combine a memory-type flag with a unit flag in each call.

Return#

Returns a single double value representing the requested memory amount in the chosen unit.

Example#

Python Example:

import maya.cmds

total_mb   = maya.cmds.mmMemorySystem(query=True, systemPhysicalMemoryTotal=True, asMegaBytes=True)
free_mb    = maya.cmds.mmMemorySystem(query=True, systemPhysicalMemoryFree=True,  asMegaBytes=True)
used_mb    = maya.cmds.mmMemorySystem(query=True, systemPhysicalMemoryUsed=True,  asMegaBytes=True)
process_mb = maya.cmds.mmMemorySystem(query=True, processMemoryUsed=True,         asMegaBytes=True)

MEL Example:

mmMemorySystem -query -systemPhysicalMemoryTotal -asMegaBytes;
mmMemorySystem -query -systemPhysicalMemoryFree  -asMegaBytes;
mmMemorySystem -query -systemPhysicalMemoryUsed  -asMegaBytes;
mmMemorySystem -query -processMemoryUsed         -asMegaBytes;

`mmTestCameraMatrix` Command#

mmTestCameraMatrix calculates an matrix (not returned) from the given camera transform and shape nodes. If the matrix matches the same matrix produced by Maya’s API, then the command returns true.

This command is used for internal tests only, it has no practical use for users.

Python Example:

cam_tfm = maya.cmds.createNode('transform', name='cam_tfm')
cam_shp = maya.cmds.createNode('camera', name='cam_shp', parent=cam_tfm)
result = maya.cmds.mmTestCameraMatrix(cam_tfm, cam_shp)
assert result == True

Other Commands#

mmReprojection Command#

Flags#

Return#

Example#

mmAnimCurveStatistics Command#

Flags#

Return#

Example#

mmAnimCurveDiffStatistics Command#

Flags#

Return#

Example#

mmAnimCurveFilterPops Command#

Flags#

Return#

Example#

mmBestFitPlane Command#

Flags#

Return#

Example#

mmMarkerHomography Command#

Flags#

Return#

Example#

mmColorIO Command#

Flags#

Return#

Example#

mmMemoryGPU Command#

Flags#

Return#

Example#

mmMemorySystem Command#

Flags#

Return#

Example#

mmTestCameraMatrix Command#

`mmReprojection` Command#

`mmAnimCurveStatistics` Command#

`mmAnimCurveDiffStatistics` Command#

`mmAnimCurveFilterPops` Command#

`mmBestFitPlane` Command#

`mmMarkerHomography` Command#

`mmColorIO` Command#

`mmMemoryGPU` Command#

`mmMemorySystem` Command#

`mmTestCameraMatrix` Command#