#include <MPxEmitterNode.h>
Base class for user defined particle emitters.
MPxEmitterNode allows the creation and manipulation of dependency graph nodes representing particle emitters.
Public Types | |
enum | MEmitterType { kDirectional = 0, kOmni, kSurface, kCurve, kVolume } |
Types of emitters. More... | |
Public Types inherited from MPxNode | |
enum | Type { kDependNode, kLocatorNode, kDeformerNode, kManipContainer, kSurfaceShape, kFieldNode, kEmitterNode, kSpringNode, kIkSolverNode, kHardwareShader, kHwShaderNode, kTransformNode, kObjectSet, kFluidEmitterNode, kImagePlaneNode, kParticleAttributeMapperNode, kCameraSetNode, kConstraintNode, kManipulatorNode, kMotionPathNode, kClientDeviceNode, kThreadedDeviceNode, kAssembly, kSkinCluster, kGeometryFilter, kBlendShape, kLast } |
Defines the type of node. More... | |
enum | SchedulingType { kParallel, kSerial, kGloballySerial, kUntrusted , kDefaultScheduling = kSerial, kSerialize = kSerial, kGloballySerialize = kGloballySerial } |
Defines the degree of parallelism of a node. More... | |
Public Member Functions | |
MPxEmitterNode () | |
Class constructor. | |
virtual | ~MPxEmitterNode () |
The class destructor. | |
virtual MPxNode::Type | type () const |
This method returns the type of the node. More... | |
virtual MStatus | compute (const MPlug &plug, MDataBlock &dataBlock) |
This method should be overridden in user defined nodes. More... | |
virtual void | draw (M3dView &view, const MDagPath &path, M3dView::DisplayStyle style, M3dView::DisplayStatus) |
Overriding this method allows the drawing of custom geometry using standard OpenGL calls. More... | |
MEmitterType | getEmitterType (MDataBlock &block) |
Retrieves the type of the emitter, determined by the "emitterType" attribute value. More... | |
MObject | getOwnerShape () |
If the emitter is a emitting from an object, this method returns the shape node for the object. More... | |
MTime | getCurrentTime (MDataBlock &block) |
Intended to be called from within the emitter's compute() method, this method returns the time at which the emitter is currently being evaluated. More... | |
MTime | getStartTime (int plugIndex, MDataBlock &block) |
Intended to be called from within the emitter's compute() method, this method returns the start times for each particle system or fluid into which the emitter is emitting. More... | |
MTime | getDeltaTime (int plugIndex, MDataBlock &block) |
Intended to be called from within the emitter's compute() method, this method returns the width of the time interval represented by the current emitter evaluation. More... | |
int | getRandomSeed (int plugIndex, MDataBlock &block) |
Intended to be called from within the emitter's compute() method, this method returns the random seed for a specified emission target (particle system or fluid shape into which the emitter is emitting). More... | |
void | getRandomState (int plugIndex, MDataBlock &block) |
Intended to be called from within the emitter's compute() method, this method copies the emitter node attribute representing the current random state for a particular emitter target into a local variable on the emitter object, to facilitate efficient random number generation using the randgen() method. More... | |
void | setRandomState (int plugIndex, MDataBlock &block) |
Intended to be called from within the emitter's compute() method, this method copies the emitter node class random state data member onto the emitter node's random state attribute. More... | |
void | resetRandomState (int plugIndex, MDataBlock &block) |
Intended to be called from within the emitter's compute() method, this method resets the emitter's random state data member. More... | |
double | randgen () |
Intended to be called from within the emitter's compute() method, this method generates a double-precision random number in the rand [0,1]. More... | |
double | getRate (MDataBlock &block) |
Intended to be called from within the emitter's compute() method, this method retrieves the "rate" attribute value common to all particle and fluid emitters. More... | |
double | getMinDistance (MDataBlock &block) |
Intended to be called from within the emitter's compute() method, this method retrieves the "minDistance" attribute value common to all particle and fluid emitters. More... | |
double | getMaxDistance (MDataBlock &block) |
Intended to be called from within the emitter's compute() method, this method retrieves the "maxDistance" attribute value common to all particle and fluid emitters. More... | |
MPoint | getWorldPosition () |
Returns the worldspace coordinates of the emitter. More... | |
MMatrix | getWorldMatrix () |
Returns the matrix that maps from the emitter's local space coordinates to worldspace. More... | |
bool | volumePrimitiveBoundingBox (MBoundingBox &box) |
For volume emitters, this method returns the object-space bounding box of the volume primitive associated with the emitter. More... | |
bool | volumePrimitivePointInside (const MPoint &worldPoint, const MMatrix &emitterWorldMatrix) |
For volume emitters, this method determines whether a particular point in space lies within the volume defined by the emitter's volume primitive. More... | |
double | volumePrimitiveDistanceFromAxis (const MPoint &worldPoint, const MMatrix &emitterWorldMatrix) |
For volume emitters, this method determines the distance from a particular point to the major axis of the volumetric primitive associated with the emitter. More... | |
bool | hasValidEmission2dTexture (const MObject &texAttr, MStatus *status=NULL) |
Certain aspects of Maya's particle and fluid emitters can be textured using 2d textures. More... | |
MStatus | evalEmission2dTexture (const MObject &texAttr, MDoubleArray &uCoords, MDoubleArray &vCoords, MVectorArray *resultColors, MDoubleArray *resultAlphas) |
If a supported 2d texture (see hasValidEmission2dTexture() method documentation) is connected to the given emitter attribute, this method can be called to evaluate that texture at a number of (u,v) texture coordinate values. More... | |
Public Member Functions inherited from MPxNode | |
MPxNode () | |
Constructor. More... | |
virtual | ~MPxNode () |
Destructor. | |
virtual void | postConstructor () |
Post constructor. More... | |
virtual bool | getInternalValue (const MPlug &, MDataHandle &) |
This method is overridden by nodes that store attribute data in some internal format. More... | |
virtual bool | setInternalValue (const MPlug &, const MDataHandle &) |
This method is overridden by nodes that store attribute data in some internal format. More... | |
virtual int | internalArrayCount (const MPlug &) const |
This method is overridden by nodes that have internal array attributes which are not stored in Maya's datablock. More... | |
virtual void | copyInternalData (MPxNode *) |
This method is overridden by nodes that store attribute data in some internal format. More... | |
virtual MStatus | legalConnection (const MPlug &, const MPlug &, bool asSrc, bool &isLegal) const |
This method allows you to check for legal connections being made to attributes of this node. More... | |
virtual MStatus | legalDisconnection (const MPlug &, const MPlug &, bool asSrc, bool &isLegal) const |
This method allows you to check for legal disconnections being made to attributes of this node. More... | |
virtual MStatus | setDependentsDirty (const MPlug &plug, MPlugArray &plugArray) |
This method can be overridden in user defined nodes to specify which plugs should be set dirty based upon an input plug {plugBeingDirtied} which Maya is marking dirty. More... | |
virtual MStatus | preEvaluation (const MDGContext &context, const MEvaluationNode &evaluationNode) |
Prepare a node's internal state for threaded evaluation. More... | |
virtual MStatus | postEvaluation (const MDGContext &context, const MEvaluationNode &evaluationNode, PostEvaluationType evalType) |
Clean up node's internal state after threaded evaluation. More... | |
virtual SchedulingType | schedulingType () const |
When overridden this method controls the degree of parallelism supported by the node during threaded evaluation. More... | |
virtual MStatus | connectionMade (const MPlug &, const MPlug &, bool asSrc) |
This method gets called when connections are made to attributes of this node. More... | |
virtual MStatus | connectionBroken (const MPlug &, const MPlug &, bool asSrc) |
This method gets called when connections are broken with attributes of this node. More... | |
virtual MStatus | dependsOn (const MPlug &, const MPlug &, bool &depends) const |
This method may be overridden by the user defined node. More... | |
virtual bool | isPassiveOutput (const MPlug &) const |
This method may be overridden by the user defined node if it wants to provide output attributes which do not prevent value modifications to the destination attribute. More... | |
virtual MStatus | shouldSave (const MPlug &, bool &isSaving) |
This method may be overridden by the user defined node. More... | |
virtual MPlug | passThroughToOne (const MPlug &) const |
This method may be overridden by nodes that have a one-to-one relationship between an input attribute and a corresponding output attribute. More... | |
virtual bool | passThroughToMany (const MPlug &, MPlugArray &) const |
This method is overridden by nodes that want to control the traversal behavior of some Maya search algorithms which traverse the history/future of shape nodes looking for directly related nodes. More... | |
virtual bool | isAbstractClass () const |
Override this class to return true if this node is an abstract node. More... | |
virtual MStringArray | getFilesToArchive (bool shortName=false, bool unresolvedName=false, bool markCouldBeImageSequence=false) const |
Use this method to return all external files used by this node. More... | |
virtual void | getExternalContent (MExternalContentInfoTable &table) const |
Returns the external content (files) that this node depends on. More... | |
bool | addExternalContentForFileAttr (MExternalContentInfoTable &, const MObject &attr) const |
Adds content info to the specified table from a file path attribute. More... | |
bool | setExternalContentForFileAttr (const MObject &attr, const MExternalContentLocationTable &) |
Sets content info in the specified attribute from the table. More... | |
virtual void | setExternalContent (const MExternalContentLocationTable &) |
Changes the location of external content in batch. More... | |
virtual MTypeId | typeId () const |
Returns the TYPEID of this node. More... | |
virtual MString | typeName () const |
Returns the type name of this node. More... | |
virtual MString | name () const |
Returns the name of this particular instance of this class. More... | |
virtual MObject | thisMObject () const |
Returns the MObject associated with this user defined node. More... | |
virtual MStatus | setExistWithoutInConnections (bool flag) |
This method specifies whether or not the node can exist without input connections. More... | |
virtual bool | existWithoutInConnections (MStatus *ReturnStatus=NULL) const |
Determines whether or not this node can exist without input connections. More... | |
virtual MStatus | setExistWithoutOutConnections (bool flag) |
This method specifies whether or not the node can exist without output connections. More... | |
virtual bool | existWithoutOutConnections (MStatus *ReturnStatus=NULL) const |
Determines whether or not this node can exist without output connections. More... | |
MDataBlock | _forceCache (const MDGContext &) |
This method is obsolete. More... | |
virtual bool | getInternalValueInContext (const MPlug &, MDataHandle &, MDGContext &) |
This method is obsolete. More... | |
virtual bool | setInternalValueInContext (const MPlug &, const MDataHandle &, MDGContext &) |
This method is obsolete. More... | |
virtual int | internalArrayCount (const MPlug &, const MDGContext &) const |
This method is obsolete. More... | |
Static Public Member Functions | |
static const char * | className () |
Returns the name of this class. More... | |
Static Public Member Functions inherited from MPxNode | |
static MStatus | addAttribute (const MObject &attr) |
This method adds a new attribute to a user defined node type during the type's initialization. More... | |
static MStatus | inheritAttributesFrom (const MString &parentClassName) |
This method allows a class of plugin node to inherit all of the attributes of a second class of plugin node. More... | |
static MStatus | attributeAffects (const MObject &whenChanges, const MObject &isAffected) |
This method specifies that a particular input attribute affects a specific output attribute. More... | |
static const char * | className () |
Returns the name of this class. More... | |
Static Public Attributes | |
static MObject | mEmitterType |
emitter type attribute | |
static MObject | mRate |
rate attribute | |
static MObject | mSpeed |
speed attribute | |
static MObject | mDirection |
direction attribute | |
static MObject | mDirectionX |
X component of mDirection. | |
static MObject | mDirectionY |
Y component of mDirection. | |
static MObject | mDirectionZ |
Z component of mDirection. | |
static MObject | mOwnerPosData |
owner postion attribute, multi | |
static MObject | mOwnerVelData |
owner velocity attribute, multi | |
static MObject | mOwnerCentroid |
owner centroid attribute | |
static MObject | mOwnerCentroidX |
X component of mOwnerCentroid. | |
static MObject | mOwnerCentroidY |
Y component of mOwnerCentroid. | |
static MObject | mOwnerCentroidZ |
Z component of mOwnerCentroid. | |
static MObject | mSweptGeometry |
input swept geometry attribute | |
static MObject | mWorldMatrix |
world matrix attribute | |
static MObject | mStartTime |
start time attribute | |
static MObject | mDeltaTime |
delta time attribute | |
static MObject | mIsFull |
flag for maximum count attribute | |
static MObject | mInheritFactor |
inherit factor attribute | |
static MObject | mSeed |
random seed attribute | |
static MObject | mRandState |
random state attribute | |
static MObject | mCurrentTime |
current time attribute | |
static MObject | mOutput |
output particle attribute, multi | |
static MObject | mMinDistance |
min distance attribute | |
static MObject | mMaxDistance |
max distance attribute | |
Static Public Attributes inherited from MPxNode | |
static MObject | message |
message attribute | |
static MObject | isHistoricallyInteresting |
is historically interesting attribute | |
static MObject | caching |
caching attribute | |
static MObject | state |
state attribute | |
static MObject | frozen |
frozen attribute | |
Additional Inherited Members | |
Protected Member Functions inherited from MPxNode | |
virtual MDataBlock | forceCache () |
USE _forceCache() IN SCRIPT. More... | |
virtual void | setMPSafe (bool flag) |
USE _setMPSafe() IN SCRIPT. More... | |
virtual MStatus | setDoNotWrite (bool flag) |
USE _setDoNotWrite() IN SCRIPT. More... | |
virtual bool | doNotWrite (MStatus *ReturnStatus=NULL) const |
USE _doNotWrite() IN SCRIPT. More... | |
virtual MDataBlock | forceCache (const MDGContext &) |
This method is obsolete. More... | |
enum MEmitterType |
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virtual |
This method returns the type of the node.
It should not be overridden by the user. It will return MPxNode::kEmitterNode.
Reimplemented from MPxNode.
Reimplemented in MPxFluidEmitterNode.
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virtual |
This method should be overridden in user defined nodes.
Recompute the given output based on the nodes inputs. The plug represents the data value that needs to be recomputed, and the data block holds the storage for all of the node's attributes.
The MDataBlock will provide smart handles for reading and writing this node's attribute values. Only these values should be used when performing computations.
When evaluating the dependency graph, Maya will first call the compute method for this node. If the plug that is provided to the compute indicates that that the attribute was defined by the Maya parent node, the compute method should return MS::kUnknownParameter. When this occurs, Maya will call the internal Maya node from which the user-defined node is derived to compute the plug's value.
This means that a user defined node does not need to be concerned with computing inherited output attributes. However, if desired, these can be safely recomputed by this method to change the behaviour of the node.
[in] | plug | plug representing the attribute that needs to be recomputed |
[in] | dataBlock | data block containing storage for the node's attributes |
Reimplemented from MPxNode.
Reimplemented in MPxFluidEmitterNode.
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virtual |
Overriding this method allows the drawing of custom geometry using standard OpenGL calls.
The OpenGL state should be left in the same state that it was in previously. The OpenGL routine glPushAttrib may be used to make this easier.
When this routine is called, the following conditions may be assumed:
As a convenience, this draw method will also be used by OpenGL's selection mechanism to determine whether this object gets selected by a particular mouse event. The user does not need to write a separate selection routine.
[in] | view | 3D view that is being drawn into |
[in] | path | to this node in the DAG |
[in] | style | style to draw object in |
MPxEmitterNode::MEmitterType getEmitterType | ( | MDataBlock & | block | ) |
Retrieves the type of the emitter, determined by the "emitterType" attribute value.
This is intended to be called from within the emitter's compute() method, in order to decide how the emitter should behave when evaluated.
[in] | block | data block containing storage for the node's attributes |
MObject getOwnerShape | ( | ) |
If the emitter is a emitting from an object, this method returns the shape node for the object.
MTime getCurrentTime | ( | MDataBlock & | block | ) |
Intended to be called from within the emitter's compute() method, this method returns the time at which the emitter is currently being evaluated.
This is equivalent to querying the "currentTime" attribute on the emitter.
[in] | block | data block containing storage for the node's attributes |
MTime getStartTime | ( | int | plugIndex, |
MDataBlock & | block | ||
) |
Intended to be called from within the emitter's compute() method, this method returns the start times for each particle system or fluid into which the emitter is emitting.
Each of these "targets" is identified by an index value corresponding to the order in which they are connected to the emitter. The start time value gives the time at which the given target is to start receiving particles or fluid. If the current time is less than the start time for a target, then nothing should be emitted into that target in the current evaluation. This value is taken by evaluating an element of the emitter node's "startTime" array attribute.
[in] | plugIndex | identifies which emitter target's start time is to be evaluated. |
[in] | block | data block containing storage for the node's attributes |
MTime getDeltaTime | ( | int | plugIndex, |
MDataBlock & | block | ||
) |
Intended to be called from within the emitter's compute() method, this method returns the width of the time interval represented by the current emitter evaluation.
Usually emitter emission rates are given as rates per second, so by converting this deltaTime value to seconds, plugin emitters can determine how many particles or how much fluid to emit in the current evaluation. This value is taken from the emitter's "deltaTime" attribute value, and can vary between different emitter targets (particle systems or fluid shapes into which the emitter is emitting), due to potential differences in oversampling settings. The "plugIndex" parameter indicates which target's time delta is being evaluated.
[in] | plugIndex | identifies which emitter target's time delta is to be evaluated. |
[in] | block | data block containing storage for the node's attributes |
int getRandomSeed | ( | int | plugIndex, |
MDataBlock & | block | ||
) |
Intended to be called from within the emitter's compute() method, this method returns the random seed for a specified emission target (particle system or fluid shape into which the emitter is emitting).
This seed value is set on the target itself, and should be used to ensure that any randomized emission behavior is repeatable when animations are played back repeatedly. The resetRandomState() method uses this value (see its documentation for details on how to implement repeatable randomized behaviour in emitters). This value is obtained by evaluating an element of the emitter's "seed" array attribute.
[in] | plugIndex | identifies which emitter target's random seed is to be evaluated. |
[in] | block | data block containing storage for the node's attributes |
void getRandomState | ( | int | plugIndex, |
MDataBlock & | block | ||
) |
Intended to be called from within the emitter's compute() method, this method copies the emitter node attribute representing the current random state for a particular emitter target into a local variable on the emitter object, to facilitate efficient random number generation using the randgen() method.
See the documentation for resetRandomState() for a description of how to use this method in conjunction with the other random stream methods of this class.
There is only one local random state data member, so care should be taken not to inadvertently overwrite this member by calling getRandomState() on one target before setRandomState() has been called on a previously-evaluated target.
[in] | plugIndex | identifies which emitter target's random state is to be copied to the local random state data member. |
[in] | block | data block containing storage for the node's attributes |
void setRandomState | ( | int | plugIndex, |
MDataBlock & | block | ||
) |
Intended to be called from within the emitter's compute() method, this method copies the emitter node class random state data member onto the emitter node's random state attribute.
See the documentation for resetRandomState() for a description of how to use this method in conjunction with the other random stream methods of this class.
There is only one local random state data member, so care should be taken not to inadvertently write the wrong random state value to the attribute by calling setRandomState() on a target before getRandomState() has been called for that target.
[in] | plugIndex | identifies which emitter target's random state is to be written from the local random state data member. |
[in] | block | data block containing storage for the node's attributes |
void resetRandomState | ( | int | plugIndex, |
MDataBlock & | block | ||
) |
Intended to be called from within the emitter's compute() method, this method resets the emitter's random state data member.
To implement repeatable randomized emitter behavior, the following steps should be followed:
This way, the emitter gets a repeatable stream of random numbers that is independent of the order of evaluation of the various emitter targets. Persistence is achieved by storing the random state on emitter attributes between evaluations, and efficiency is achieved by using a local random state variable during evaluations.
[in] | plugIndex | identifies which emitter target's random state is to be reset. |
[in] | block | data block containing storage for the node's attributes |
double randgen | ( | ) |
Intended to be called from within the emitter's compute() method, this method generates a double-precision random number in the rand [0,1].
The emitter object's random state data member is used to generate the random number, and will be updated after the number is generated. To generate a stream of random numbers for a particular target, ensure that getRandomState() is called before calling randgen(), and that setRandomState() is called after all the random numbers have been generated. See the documentation for resetRandomState() for a description of how to use this method in conjunction with the other random stream methods of this class.
double getRate | ( | MDataBlock & | block | ) |
Intended to be called from within the emitter's compute() method, this method retrieves the "rate" attribute value common to all particle and fluid emitters.
For particle emitters, this indicates the number of particles to be emitted per second. For fluid emitters, this value is usually used as a multiplier applied to the emission rates for various fluid grids such as density, temperature, etc.
[in] | block | data block containing storage for the node's attributes |
double getMinDistance | ( | MDataBlock & | block | ) |
Intended to be called from within the emitter's compute() method, this method retrieves the "minDistance" attribute value common to all particle and fluid emitters.
This value indicates the minimum distance from the emitter center at which fluid or particles will be emitted.
[in] | block | data block containing storage for the node's attributes |
double getMaxDistance | ( | MDataBlock & | block | ) |
Intended to be called from within the emitter's compute() method, this method retrieves the "maxDistance" attribute value common to all particle and fluid emitters.
This value indicates the maximum distance from the emitter center at which fluid or particles will be emitted.
[in] | block | data block containing storage for the node's attributes |
MPoint getWorldPosition | ( | ) |
Returns the worldspace coordinates of the emitter.
For curve, surface, and volume emitters, this returns the worldspace coordinates of the center of the emitter's local space. For point emitters, this value usually corresponds to the position of the emitter object itself.
MMatrix getWorldMatrix | ( | ) |
Returns the matrix that maps from the emitter's local space coordinates to worldspace.
bool volumePrimitiveBoundingBox | ( | MBoundingBox & | box | ) |
For volume emitters, this method returns the object-space bounding box of the volume primitive associated with the emitter.
[out] | box | receives the object space bounding box for the emission volume primitive. |
For volume emitters, this method determines whether a particular point in space lies within the volume defined by the emitter's volume primitive.
[in] | worldPoint | worldspace coordinates of the point to be tested. |
[in] | emitterWorldMatrix | object to worldspace matrix for the emitter, which can be obtained using the MPxEmitterNode::getWorldMatrix() method. |
double volumePrimitiveDistanceFromAxis | ( | const MPoint & | worldPoint, |
const MMatrix & | emitterWorldMatrix | ||
) |
For volume emitters, this method determines the distance from a particular point to the major axis of the volumetric primitive associated with the emitter.
For fluid emitters, this distance can be used to implement simple emission dropoff behavior.
[in] | worldPoint | worldspace coordinates of the point to be tested. |
[in] | emitterWorldMatrix | object to worldspace matrix for the emitter, which can be obtained using the MPxEmitterNode::getWorldMatrix() method. |
Certain aspects of Maya's particle and fluid emitters can be textured using 2d textures.
For example, surface particle emitters can use a 2d texture to modulate the emission rate over the surface. For these purposes, only a subset of Maya's textures are supported, namely the default 2d textures (bulge, checker, cloth, file, fluid texture 2d, fractal, grid, mountain, movie, noise, ocean, ramp, water). No other nodes are supported. This method takes an attribute on an emitter, and determines if there is a supported texture connected to it. If the texture is supported, then the evalEmission2dTexture() method can be called to evaluate the texture at various (u,v) coordinate values.
[in] | texAttr | attribute to be tested for a valid texture connection. |
[out] | status | status code. |
MStatus evalEmission2dTexture | ( | const MObject & | texAttr, |
MDoubleArray & | uCoords, | ||
MDoubleArray & | vCoords, | ||
MVectorArray * | resultColors, | ||
MDoubleArray * | resultAlphas | ||
) |
If a supported 2d texture (see hasValidEmission2dTexture() method documentation) is connected to the given emitter attribute, this method can be called to evaluate that texture at a number of (u,v) texture coordinate values.
[in] | texAttr | attribute whose connected texture is to be evaluated. |
[in] | uCoords | array of u coordinate values |
[in] | vCoords | array of v coordinate values |
[out] | resultColors | if non-NULL, receives the result of the connected texture's outColor attribute, evaluated at all the (u,v) coordinates given by the uCoords and vCoords arrays. |
[out] | resultAlphas | if non-NULL, receives the outAlpha values evaluated from the texture at these same points. |
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static |
Returns the name of this class.