API Guide

Overview of example plug-ins

There are a large number of example plug-ins supplied with the Maya Development Tool Kit. These are described in this chapter to help you find one that demonstrates the operation you are trying to accomplish. The following naming convention is used by the examples so you can tell what kind of plug-in the example is based on its file name.

Suffix	Description
Cmd	Plug-ins that create new commands.
Tool	Plug-ins that create new interactive tools.
Node	Plug-ins that create new node types.
Translator	Plug-ins that create new file translators.
Shader	Plug-ins that create new shading nodes.
Manip	Plug-ins that create new manipulators.
Field	Plug-ins that create new dynamic fields.
Emitter	Plug-ins that create new dynamic emitters.
Spring	Plug-ins that create new dynamic springs.
Shape	Plug-ins that create new shapes.

MEL command plug-ins

blindComplexDataCmd	Command which demonstrates adding more complex blind data, as a user defined data type, to an object. See blindComplexDataCmd.
blindDoubleDataCmd	Command which demonstrates adding blind data, as a user-defined data type, to an object. See blindDoubleDataCmd.
blindShortDataCmd	Command which demonstrates adding blind data to an object. See blindShortDataCmd.
closestPointCmd	command that shows how to use the MMeshIntersector class to find the closest point between a point light and a mesh
closestPointOnCurve	Command that sets the weights of the CVs of a cluster according to a mathematical function. See closestPointOnCurve.
convertBumpCmd	Command that demonstrates the steps necessary to create a non-linear animation clip using the API. See convertBumpCmd.
convertEdgesToContainedFacesCmd	Command that converts a selection of edges into a selection of faces that interconnect. See convertEdgesToContainedFacesCmd.
convertVerticesToContainedEdgesCmd	Command that converts a selection of vertices into a selection of edges that interconnect the original vertices. See convertVerticesToContainedEdgesCmd.
convertVerticesToContainedFacesCmd	Command that converts a selection of vertices into a selection of faces that interconnect the original vertices. See convertVerticesToContainedFacesCmd.
cvExpandCmd	Command that splits NURBS CV selections up into one string per selected CV. See cvExpandCmd.
cvPosCmd	Return the world or local space position of a NURBS CV or a poly vertex. See cvPosCmd.
dagPoseInfoCmd	Command that demonstrates how to extract DAG pose info for a skeleton’s bind pose, or for other poses created using the “dagPose” command. See dagPoseInfoCmd.
deletedMsgCmd	A new example that demonstrates each of the node deletion callbacks available.
deletedMsgCmd	command that demonstrates each of the node deletion callbacks that are available in the API. The command registers callbacks on selected nodes that will trigger messages in the console when the command is run
dynExprFieldTest	A new example that demonstrates the per particle field attributes support that has been added to the class MPxFieldNode.
exportJointClusterDataCmd	command that demonstrates how to find all joint cluster nodes and uses the MFnWeightGeometryFilter function set and MItGeometry iterator to export weights per CV for each geometry deformed by each joint cluster.
exportSkinClusterDataCmd	command that exports smooth skin data to an alternate format
findFileTexturesCmd	locate the file texture nodes in a scene
findTexturesPerPolygonCmd	locate the file texture nodes assigned to each polygon
flipUVCmd	demonstration the use of the MPxPolyTweakUVCommand class to manipulate UVs
helix2Cmd	command which implements undo and redo
helixTool	tool which uses OpenGL to draw out guidelines
helloCmd	trivial command that takes arguments
helloWorldCmd	first simple command
idleTest	display the attribute dependencies within a node
instanceCallbackCmd	A new example that demonstrates listening to instance add and remove messages.
instancerListCmd	demonstrates how to use the MFnInstancer and MItInstancer classes to enumerate all particle instances in a scene.
intersectCmd	an example that demonstrates how to find the intersection points between a mesh and a spotlight. This example demonstrates the accelerated intersection methods of MFnMesh
listLightLinksCmd	command to query light linking information
listPolyHolesCmd	command that produces a list of all the holes in each selected poly mesh
lockEvent	demonstrates the API callbacks for node and plug locking
marqueeTool	command which implements mouse selection
meshOpCmd	demonstrates the use of the high-level polygon API methods that have been added to MFnMesh
meshReorderCmd	command that will re-index a polygon mesh based on a user defined starting face
motionPathCmd	command to animate an object along a motion path
motionTraceCmd	command that evaluates the position of a keyframed object over time and draws a motion path curve
moveCurveCVsCmd	command that moves CVs to the origin
nodeInfoCmd	command which demonstrates walking the dependency graph
nodeMessageCmd	command that adds a callback for all the nodes on the active selection list
particlePathsCmd	command that uses particle ID information from the API to derive a set of NURBS curves from the position of particles over time
particleSystemInfoCmd	demonstrates the use of the new MFnParticleSystem class for retrieving particle information
pfxInfoCmd	an example that demonstrates how to extract the render line information from Maya® Paint Effects™
pickCmd	command to pick objects by name
pointOnMeshInfo	both a MEL command and a DG node that computes the worldspace position and normal on a poly mesh
polyMessageCmd	A new example that demonstrates the use of the MPolyMessage class to listen to vertex, edge and face component id changes.
polyPrimitiveCmd	command to create polygons
progressWindowCmd	A new example that demonstrates the use of the MProgressWindow class.
referenceQueryCmd	command to find useful information about the referenced files in a scene
renderViewInteractiveRenderCmd	A new example that demonstrates the immediate feedback setting that has been added to the startRender() methods of the MRenderView class.
scanDagCmd	command which demonstrates walking the DAG
scanDagSyntax	command which demonstrates walking the DAG as well as using syntax objects to parse the arguments to the command
spiralAnimCurveCmd	command to move objects in a spiral
splitUVCmd	command to unshare or “split” select UVs on a poly mesh
surfaceCreateCmd	command that creates a NURBS surface from CVs and knots using the MFnNurbsSurface function set
surfaceTwistCmd	command which modifies the CV positions of NURBS surfaces or the vertex positions of polygons in order to twist the surface around the y-axis
threadTestCmd	command that shows how to use the MThreadPool thread class
threadTestWithLocksCmd	command that shows how to use the MThreadPool and MSpinLock threading classes
translateCmd	command to translate objects
undoRedoMsgCmd	A new example that demonstrates the use of the new Undo and Redo events that have been added to the MEventMessage class.
userMsgCmd	A new example that demonstrates the use of the MUserEventMessage class. This example allows the creation, removal and posting of user-defined events identified by strings.
userMsgCmd	command that demonstrates how user-defined messages can be used. The command supports options to register, deregister, and post named events through the API. This example uses callbacks that simply print a message when they are entered.
viewCallbackTest	an example that demonstrates how to listen to the pre render, post render, view destroyed callbacks
volumeLightCmd	demonstrates the use of the MFnVolumeLight class
whatisCmd	command that prints API type information about objects
zoomCameraCmd	command to zoom the view through a camera

Dependency Graph Node Plug-ins

affectsNode	a new example that demonstrates the use of the MPxNode::setDependentsDirty() method. This new method allows for attributeAffects() relationships involving dynamic and non-dynamic (i.e. static) Maya attributes.
animCubeNode	an example of a dependency node that creates a polygonal mesh from scratch and outputs that mesh in a dependency graph attribute.
apiMeshShape	an example of a shape node that registers a new kind of polygonal mesh, as well as geometry data specific for the shape and a node that can create this new shape type
apiSimpleShape	an example of a shape node that demonstrates how to work with components. Uses the MPxComponentShape class.
arcLenNode	a simple example of a node that takes geometry as input
buildRotationNode	a simple node which performs an algebraic computation
circleNode	a more complex procedural animation example
closestPointOnCurve	command that sets the weights of the CVs of a cluster according to a mathematical function
componentScaleManip	a complex example that demonstrates how to use conversion functions with a scale manipulator to control vertex positions.
curveArrowsNode	demonstrates the use of transparency and draw “last” functionality of MPxLocatorNode
customImagePlane	demonstrates how to create a user defined image plane
cvColorNode	an example of a locator dependency node that draws colored points on top of each CV of a NURBS surface.
cvColorShader	allows vertex color (CPV) to be software rendered
exampleMRampAttribute	an example that demonstrates how to implement a ramp attribute on a custom node
footPrintManip	an example of a locator dependency node that has a corresponding manipulator. The Show Manip Tool can be used when the footPrint locator is selected to show the footPrint manipulator.
footPrintNode	an example of a locator dependency node. Locators are actually DAG nodes that have draw methods that the user may override. This particular locator draws a foot print.
fullLoftNode	an example of a real loft dependency node that builds a NURBS surface from an array of NURBS curves.
genericAttributeNode	demonstrates how to create and use generic attributes on a node.
geometrySurfacConstraint	demonstrates how to create a user defined constraint
jitterNode	a simple multi-purpose procedural node
latticeNoise	a complex example of geometry modification in a dependency node, along with a command that does low level dependency graph access to hook up the node
multiCurveNode	an example of a dependency node that uses the MArrayDataBuilder class.
NodeMonitor	class that monitors a given node
offsetNode	an example of a deformer dependency node that offsets vertices according to the CV’s weights.
particleAttrNode	demonstrates how to define a custom node which maps per-particle data to a particle shape
pnTrianglesNode	ATI Radeon specific hardware shader plug-in
pointOnMeshInfo	both a MEL command and a DG node that computes the worldspace position and normal on a poly mesh
pointOnSubdNode	an example of how to query a subdivision surface as an input to a dependency node
polyTrgNode	an example of how to add user defined triangulation for meshes using the poly API class, MPxPolyTrg
quadricShape	an example of a simple shape node that implements a quadric shape using the OpenGL gluQuadric functions.
rockingTransform	an example that demonstrates how to implement a MPxTransform that defines a rocking motion.
rockingTransformCheck	an example that demonstrates how to implement a MPxTransform that defines a rocking motion and performs checks on the user entered values
rotateManip	an example that demonstrates the different settings for the rotate manipulator.
shellNode	a dependency graph node that procedurally generates sea shells and outputs them as meshes.
simpleLoftNode	a node that implements a user-defined loft function on a curve with construction history. Also demonstrates how to pass geometry (a NURBS surface) to an internal dependency node.
sineNode	a simple procedural animation example
stringFormatNode	demonstrates how to use strings as input and output attributes
surfaceBumpManip	this example demonstrates how to use the pointOnSurface manipulator to modify vertices near the manipulator position on the surface
swissArmyManip	a contrived example that attaches all existing user-defined manipulators to a node.
transCircleNode	an example of a dependency node that uses the translate attribute as both an input and output. Demonstrates how to transfer all of X, Y, and Z attributes via a single dependency graph connections. It also contains an example attribute editor template.
weightListNode	an example that demonstrates how to work with multi of multi attributes as is found in the weightList attribute of a deformer
yTwistNode	an example of a deformer dependency node that twists the deformed vertices around the y-axis.

User-defined dependency graph nodes—creating dynamics nodes

These user-defined dependency graph nodes create dynamics nodes derived from MPxEmitterNode, MPxSpringNode, and MPxFieldNode.

ownerEmitter	an example particle emitter node that emits in a direction from multiple points defined by a particle shape.
simpleEmitter	an example particle emitter node that emits in a direction from a single point.
simpleFluidEmitter	an example fluid emitter node that demonstrates how to use the new MPxFluidEmitterNode class to implement most of the functionality of Maya’s standard fluid emitters
simpleSpring	an example spring node that defines the spring law that is used in a simulation.
sweptEmitter	an example particle emitter node that emits in a direction from points on a curve or surface.
torusField	an example field node that implements an attract-repel field between itself and a distance.

Rendering plug-ins

blastCmd	demonstrates how to use the off screen rendering API extension.
blindDataMesh	demonstrates the use of blind data to provide color information to a hardware shading node.
CgFx Shader	a hardware shader plug-in with many advanced possibilities.
renderAccessNode	demonstrates how to work with render callbacks.
renderViewRenderCmd	demonstrates how to render a full image to the Render View window using the MRenderView class.
renderViewRenderRegionCmd	demonstrates how to use the MRenderView class to update the currently selected Render Region in Maya's Render View.
sampleCmd	demonstrates how to sample shading groups or nodes using MRenderUtil::sampleShadingNetwork().
sampleParticles	demonstrates how to sample shading groups or nodes using MRenderUtil::sampleShadingNetwork() to assign colors to a particle object.
ShadingConnection	a class that stores useful information about a shader’s attribute, including what’s connected upstream of it.
ShapeMonitor	a class that watches shape or texture nodes and keeps track of changes since the last export.
shiftNode	demonstrate modifying uvCoord and refPointCamera from within a texture plug-in
hwManagedTextureShader	demonstrates how to manage texture caching efficiently
OpenGLViewportRenderer	demonstrates how to override the Maya viewport drawing
D3DViewportRenderer	demonstrates how Direct3D can be used to render into a Maya viewport (Windows only)

Miscellaneous plug-ins

The following lists several miscellaneous plug-ins.

conditionTest	display which “conditions” are being changed inside Maya
ddsFloatReader	demonstrates how to define a .dds float file format reader
eventTest	display which “events” are being changed inside Maya
filterAsciiFile	demonstrates how to control the filtering of a Maya ASCII file
hairCollisionSolver	demonstrates how to use MHairSystem to override Maya’s object to hair collision algorithm
helixMotifCmd	create a new Motif window containing a button that creates a helix when pressed. This plug-in is only available on Linux.
idleTest	using both idle messages and UI deleted messages in a plug-in
iffInfoCmd	extracts information from an IFF image file.
iffPixelCmd	extracts a pixel value from an IFF image file.
iffPpmCmd	converts an IFF image file to a PPM image file.
jlcVcrDevice	creates a user defined midi input device for the JL-Cooper midi VCR control box. This plug-in is only available on Linux.
lepTranslator	an example file translator that defines its own magic number and reads MEL commands
maTranslator	an example of a file translator that approximates the MayaAscii file
moveManip	A simple manipulator that demonstrates how the freePointTriad and distance manipulators can be used with an user-defined context.
moveNumericTool	Selection-action tool that performs translations in orthographic views as well as allowing the user to type in precise translation values to while in the move tool.
moveTool	Selection-action tool that performs translations in orthographic views.
pnTrianglesNode	This node is a simple example of how to query a subdivision surface as an input to a dependency node.
simpleImageFile	demonstrates how to define a new image file format
simpleSolverNode	an example of a simple user defined single-bone IK-solver in the x-y plane that is registered through createNode. By registering the plug-in solver through createNode, the registration mechanism is the same as non-default IK solvers such as the ikMCsolver.
tiffFloatReader	demonstrates how to define a .tif float file format reader
viewCaptureCmd	uses OpenGL to capture the current 3D view and write it into a PPM file

Shader source code examples

Shader source code examples are provided in Shader source code examples.

System plug-ins

The following table lists the source for several of the system plug-ins shipped with Maya. Unlike most of the other examples, these are complex samples of real production plug-ins.

Detailed documentation for each of these can be found in the Translators guide as compiled versions of these are shipped as part of the Maya package. The following shows the current list.

animImportExport	A translator that allows you to move animation information between scenes.
objExport	A Wavefront OBJ export translator
ribExport	A Pixer® RenderMan® RIB export translator