Solve Commands#

`mmSolver` Command#

The command named mmSolver is the primary command used to perform a solve.

Flags#

The command can be run in both MEL and Python.

Here is a table of command flags, as currently specified in the command.

Command Flag	Command Flag (short)	Type	Description	Default Value
-camera	-c	string, string	Camera transform and shape nodes.	None
-marker	-m	string, string, string	Marker, Camera, Bundle.	None
-attr	-a	string, string, string, string, string	Node attribute, min value, max value, offset and scale.	None
-frame	-f	long int	Frame number to solve with.	1
-attrStiffness	-asf	string, string, string, string	Node attribute, weight plug name, variance plug name, value plug name.	None
-attrSmoothness	-asm	string, string, string, string	Node attribute, weight plug name, variance plug name, value plug name.	None
-solverType	-st	unsigned int	Type of solver to use.	<auto detected>
-sceneGraphMode	-sgm	unsigned int	The Scene Graph used; 0=Maya DAG, 1=MM Scene Graph.	0 (Maya DAG)
-timeEvalMode	-tem	unsigned int	How to evalulate values at different times, 0=DG Context 1=Set Time.	0 (DG Context)
-iterations	-it	unsigned int	Maximum number of iterations.	20
-tauFactor	-t	double	Initial Damping Factor.	1E-03
-functionTolerance	-ftl	double	Acceptable function change.	1E-06
-parameterTolerance	-ptl	double	Acceptable parameter change.	1E-06
-gradientTolerance	-gtl	double	Acceptable gradient error.	1E-06
-delta	-dt	double	Change to the guessed parameters each iteration.	1E-04
-autoDiffType	-adt	unsigned int	Auto-differencing type 0=forward 1=central.	0 (forward)
-verbose	-v	bool	Prints more information.	False

Return#

The mmSolver command will return a list of strings.

The list of strings has a specific structure and stores all the data from the core solver engines, so the user can do whatever they wish to.

Example#

Python Example:

maya.cmds.mmSolver(
    camera=('camera1', 'cameraShape1'),
    marker=(
        ('marker1', 'camera1', 'bundle1'),
        ('marker2', 'camera1', 'bundle2'),
    ),
    attr=(
        ('node.attr', 'None', 'None', 'None', 'None'),
        ('bundle1.tx', 'None', 'None', 'None', 'None'),
        ('bundle1.ty', 'None', 'None', 'None', 'None'),
        ('camera1.rx', '-10.0', '25.0', '360.0', '1.0'),
    ),
    frame=(1, 12, 24,),
    iterations=10,
)

MEL Example:

mmSolver
    -camera "camera1" "cameraShape1"
    -marker "marker1" "camera1" "bundle1"
    -marker "marker2" "camera1" "bundle2"
    -attr "node.attr" "None" "None" "None" "None"
    -attr "bundle1.tx" "None" "None" "None" "None"
    -attr "bundle1.ty" "None" "None" "None" "None"
    -attr "camera1.rx" "-10.0" "25.0" "360.0" "1.0"
    -frame 1
    -frame 12
    -frame 24
    -iterations 10;

`mmSolverType` Command#

mmSolverType queries the available solver back-ends compiled into the plug-in and reports which one is used by default.

This command is commonly used to adapt scripts to whichever solvers are present. See How do I get the list of supported Solver Types? for more detail.

Flags#

All flags require -query mode (the command does not support edit mode).

Command Flag	Command Flag (short)	Type	Description	Default Value
-list	-ls	bool	Return a list of all available solver types.	False
-default	-def	bool	Return the default solver type.	False
-name	-n	string	Filter output to include the solver name.	(auto)
-index	-idx	unsigned	Filter output to include the solver index.	(auto)

Note

-list and -default are mutually exclusive. When either is given without -name or -index, both name and index are returned by default.

Return#

Returns a string array (when -list is used) or a single string (when -default is used). Each entry has the form <index>=<name> when both -name and -index are active, otherwise just the index or name alone.

Example#

Python Example:

# List all available solvers (returns e.g. ["0=cminpack_lm", "1=ceres"])
solvers = maya.cmds.mmSolverType(query=True, list=True)

# Query the default solver
default_solver = maya.cmds.mmSolverType(query=True, default=True)

MEL Example:

// List all available solvers
mmSolverType -query -list true;

// Get default solver
mmSolverType -query -default true;

`mmSolverAffects` Command#

mmSolverAffects analyses the dependency relationships between markers and attributes and caches those relationships as custom attributes on the marker nodes. The solver uses this cached data to partition a solve into independent sub-problems, improving performance.

The command accepts the same -camera, -marker, -attr, and -frame flags as mmSolver. The -frame flag is optional; the command works with time-independent data.

Flags#

Command Flag	Command Flag (short)	Type	Description	Default Value
-camera	-c	string, string	Camera transform and shape nodes.	None
-marker	-m	string, string, string	Marker, Camera, Bundle.	None
-attr	-a	string × 5	Node attribute, min, max, offset, scale.	None
-frame	-f	long int	Frame number (optional).	None
-mode	-md	string	Operation mode; see values below.	None
-graphMode	-gmd	string	Graph representation mode; see values below.	`"node_name"`

Mode values (-mode):

"addAttrsToMarkers" — compute the affects relationship and write it as custom attributes on each marker node. This is the normal use case and the operation is undoable.
"returnString" — return the relationship data as a string instead of modifying nodes.

Graph mode values (-graphMode):

"normal" — full graph with all details.
"node_name" — identify graph nodes by their Maya node name (default).
"object" — identify graph nodes by their Python object representation.
"simple" — simplified graph with minimal detail.

Return#

With -mode "addAttrsToMarkers": modifies marker nodes in-place and returns nothing.

With -mode "returnString": returns a string encoding the affects-relationship graph.

Example#

Python Example:

import maya.cmds

maya.cmds.mmSolverAffects(
    camera=('camera1', 'camera1Shape'),
    marker=('myMarker', 'camera1Shape', 'myBundle'),
    attr=('myBundle.translateX', 'None', 'None', 'None', 'None'),
    mode='addAttrsToMarkers',
)

MEL Example:

mmSolverAffects
    -camera "camera1" "camera1Shape"
    -marker "myMarker" "camera1Shape" "myBundle"
    -attr "myBundle.translateX" "None" "None" "None" "None"
    -mode "addAttrsToMarkers";

`mmSolverSceneGraph` Command#

mmSolverSceneGraph validates whether the given scene objects can be used to construct a scene graph of the requested type. It accepts the same object and frame flags as mmSolver and returns true if construction succeeds, or false otherwise.

This is useful for detecting in advance whether the MM Scene Graph (-sceneGraphMode 1) will work for a given set of inputs, so that calling code can fall back to the Maya DAG scene graph if needed.

The command is not undoable.

Flags#

Command Flag	Command Flag (short)	Type	Description	Default Value
-camera	-c	string, string	Camera transform and shape nodes.	None
-marker	-m	string, string, string	Marker, Camera, Bundle.	None
-attr	-a	string × 5	Node attribute, min, max, offset, scale.	None
-frame	-f	long int	Frame number to test with.	None
-sceneGraphMode	-sgm	unsigned int	Scene graph type; 0=Maya DAG, 1=MM Scene Graph.	0 (Maya DAG)
-mode	-md	string	Operation mode; only `"debugConstruct"` is currently valid.	None

Return#

Returns true if the scene graph was constructed without errors, false otherwise.

Example#

Python Example:

import maya.cmds

result = maya.cmds.mmSolverSceneGraph(
    camera=('camera1', 'camera1Shape'),
    marker=('myMarker', 'camera1Shape', 'myBundle'),
    attr=('myBundle.translateX', 'None', 'None', 'None', 'None'),
    frame=1,
    sceneGraphMode=1,
    mode='debugConstruct',
)
if not result:
    print('MM Scene Graph is not supported; falling back to Maya DAG.')

MEL Example:

int $ok = `mmSolverSceneGraph
    -camera "camera1" "camera1Shape"
    -marker "myMarker" "camera1Shape" "myBundle"
    -attr "myBundle.translateX" "None" "None" "None" "None"
    -frame 1
    -sceneGraphMode 1
    -mode "debugConstruct"`;

`mmCameraRelativePose` Command#

mmCameraRelativePose computes the relative pose (position and rotation) of one camera with respect to another using 2D marker correspondences observed at two different frames. This is a Structure from Motion (SfM) operation based on the essential matrix.

At least five marker correspondences are required. When -setValues true is given the computed poses are written to the camera transform nodes (undoable).

Flags#

Command Flag	Command Flag (short)	Type	Description	Default Value
-cameraA	-ca	selection item	Camera A transform node.	None
-cameraB	-cb	selection item	Camera B transform node.	None
-frameA	-fa	long int	Frame number for camera A.	1
-frameB	-fb	long int	Frame number for camera B.	10
-markerBundle	-mb	string, string, string	Marker on frame A, marker on frame B, bundle (multi-use).	None
-bundlePosition	-bp	double, double, double	World-space XYZ of a bundle (multi-use, optional).	None
-setValues	-sv	bool	Write computed poses to the camera transform nodes.	False
-useCameraTransform	-ct	bool	Use an existing camera world-space transform as the reference frame.	False

Return#

Returns an empty result. Camera transform values are set directly on the nodes when -setValues true is given.

Example#

Python Example:

import maya.cmds

maya.cmds.mmCameraRelativePose(
    cameraA='cameraA',
    cameraB='cameraB',
    frameA=1,
    frameB=10,
    markerBundle=[
        ('markerA1', 'markerB1', 'bundle1'),
        ('markerA2', 'markerB2', 'bundle2'),
        ('markerA3', 'markerB3', 'bundle3'),
        ('markerA4', 'markerB4', 'bundle4'),
        ('markerA5', 'markerB5', 'bundle5'),
    ],
    setValues=True,
)

MEL Example:

mmCameraRelativePose
    -cameraA "cameraA"
    -cameraB "cameraB"
    -frameA 1
    -frameB 10
    -markerBundle "markerA1" "markerB1" "bundle1"
    -markerBundle "markerA2" "markerB2" "bundle2"
    -markerBundle "markerA3" "markerB3" "bundle3"
    -markerBundle "markerA4" "markerB4" "bundle4"
    -markerBundle "markerA5" "markerB5" "bundle5"
    -setValues true;

`mmCameraPoseFromPoints` Command#

mmCameraPoseFromPoints computes a camera pose (position and rotation) at one or more frames from known 3D bundle positions and their corresponding 2D marker positions (Perspective-n-Point, PnP).

Paired -marker (2D) and -bundle (3D) inputs must be provided in matching order. When -setValues true is given the result is written to the camera transform node at each frame (undoable).

Flags#

Command Flag	Command Flag (short)	Type	Description	Default Value
-camera	-c	selection item	Camera transform node to solve.	None
-frame	-f	unsigned int	Frame number to compute the pose at (multi-use).	None
-marker	-m	string, string	Marker node and camera shape node (multi-use).	None
-bundle	-b	string	Bundle node corresponding to each marker (multi-use).	None
-setValues	-sv	bool	Write the computed pose to the camera transform node.	False

Return#

Returns an empty result. Camera transform values are set directly on the node at each frame when -setValues true is given.

Example#

Python Example:

import maya.cmds

maya.cmds.mmCameraPoseFromPoints(
    camera='camera1',
    frame=(1, 2, 3),
    marker=[
        ('marker1', 'camera1Shape'),
        ('marker2', 'camera1Shape'),
        ('marker3', 'camera1Shape'),
        ('marker4', 'camera1Shape'),
    ],
    bundle=['bundle1', 'bundle2', 'bundle3', 'bundle4'],
    setValues=True,
)

MEL Example:

mmCameraPoseFromPoints
    -camera "camera1"
    -frame 1
    -frame 2
    -frame 3
    -marker "marker1" "camera1Shape"
    -marker "marker2" "camera1Shape"
    -marker "marker3" "camera1Shape"
    -marker "marker4" "camera1Shape"
    -bundle "bundle1"
    -bundle "bundle2"
    -bundle "bundle3"
    -bundle "bundle4"
    -setValues true;

`mmCameraSolve` Command#

mmCameraSolve is the higher-level camera solver command used by the Camera Solver tool. It accepts a selection list of camera transform nodes and marker nodes, reads the marker 2D positions at the given frame range, and runs the SfM-based camera solve pipeline.

Note

The full solve is currently implemented in Python (see python/mmSolver/_api/solvercamerautils.py). This C++ command handles argument parsing and data preparation but delegates the heavy computation to the Python layer. The command is not undoable.

Flags#

Command Flag	Command Flag (short)	Type	Description	Default Value
-startFrame	-sf	unsigned int	First frame of the range to solve.	1
-endFrame	-ef	unsigned int	Last frame of the range to solve.	120

In addition to the flags, pass the camera transform and marker nodes as command objects (the selection list).

Return#

Returns an empty array. Results are applied to the scene by the calling Python code.

Example#

Python Example:

import maya.cmds

maya.cmds.mmCameraSolve(
    'camera1',
    'marker1', 'marker2', 'marker3',
    startFrame=1,
    endFrame=120,
)

MEL Example:

mmCameraSolve
    -startFrame 1
    -endFrame 120
    camera1 marker1 marker2 marker3;

`mmSolver_v2` Command#

mmSolver_v2 is the second iteration of the mmSolver command with a cleaner flag syntax. It performs the same non-linear least-squares solve but drops the deprecated -verbose, -attrStiffness, -attrSmoothness, and -removeUnused* flags, and adds flags for results output and marker-deviation attributes.

The command is undoable.

Flags#

Return#

Returns true (integer 1) if the solve completed without error, false (0) otherwise. Solve quality statistics are printed according to -logLevel and written to -resultsNode when provided.

Example#

Python Example:

import maya.cmds

result = maya.cmds.mmSolver_v2(
    camera=('camera1', 'cameraShape1'),
    marker=(
        ('marker1', 'camera1', 'bundle1'),
        ('marker2', 'camera1', 'bundle2'),
    ),
    attr=(
        ('bundle1.tx', 'None', 'None', 'None', 'None'),
        ('bundle1.ty', 'None', 'None', 'None', 'None'),
        ('camera1.rx', '-10.0', '25.0', 'None', 'None'),
    ),
    frame=(1, 12, 24),
    iterations=20,
    logLevel=2,
    setMarkerDeviationAttrs=True,
)
print('Solve succeeded:', result)

MEL Example:

int $ok = `mmSolver_v2
    -camera "camera1" "cameraShape1"
    -marker "marker1" "camera1" "bundle1"
    -marker "marker2" "camera1" "bundle2"
    -attr "bundle1.tx" "None" "None" "None" "None"
    -attr "bundle1.ty" "None" "None" "None" "None"
    -attr "camera1.rx" "-10.0" "25.0" "None" "None"
    -frame 1
    -frame 12
    -frame 24
    -iterations 20
    -logLevel 2
    -setMarkerDeviationAttrs true`;

Solve Commands#

mmSolver Command#

Flags#

Return#

Example#

mmSolverType Command#

Flags#

Return#

Example#

mmSolverAffects Command#

Flags#

Return#

Example#

mmSolverSceneGraph Command#

Flags#

Return#

Example#

mmCameraRelativePose Command#

Flags#

Return#

Example#

mmCameraPoseFromPoints Command#

Flags#

Return#

Example#

mmCameraSolve Command#

Flags#

Return#

Example#

mmSolver_v2 Command#

Flags#

Return#

Example#

`mmSolver` Command#

`mmSolverType` Command#

`mmSolverAffects` Command#

`mmSolverSceneGraph` Command#

`mmCameraRelativePose` Command#

`mmCameraPoseFromPoints` Command#

`mmCameraSolve` Command#

`mmSolver_v2` Command#