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Synopsis

insertKnotCurve [-addKnots boolean] [-caching boolean] [-constructionHistory boolean] [-curveOnSurface boolean] [-insertBetween boolean] [-name string] [-nodeState int] [-numberOfKnots int] [-object boolean] [-parameter float] [-replaceOriginal boolean] curve

insertKnotCurve is undoable, queryable, and editable.

The insertKnotCurve command inserts knots into a curve given a list of parameter values. The number of knots to add at each parameter value and whether the knots are added or complemented can be specified. The name of the curve is returned. If construction history is on, the name of the resulting dependency node is also returned.

An edit point will appear where you insert the knot. Also, the number of spans and CVs in the curve will increase in the area where the knot is inserted.

You can insert up to "degree" knots at a curve parameter that isn't already an edit point. eg. for a degree three curve, you can insert up to 3 knots.

Use this operation if you need more CVs in a local area of the curve. Use this operation (or "hardenPoint") if you want to create a corner in a curve.

Return value

string[]Object name and node name

In query mode, return type is based on queried flag.

Flags

addKnots, caching, constructionHistory, curveOnSurface, insertBetween, name, nodeState, numberOfKnots, object, parameter, replaceOriginal
Long name (short name) Argument types Properties
-addKnots(-add) boolean createqueryedit
Whether to add knots or complement. Complement means knots will be added to reach the specified number of knots.
Default: true
-caching(-cch) boolean createqueryedit
Toggle caching for all attributes so that no recomputation is needed
-insertBetween(-ib) boolean createqueryedit
If set to true, and there is more than one parameter value specified, the knots will get inserted at equally spaced intervals between the given parameter values, rather than at the parameter values themselves.
Default: false
-nodeState(-nds) int createqueryedit

Maya dependency nodes have 6 possible states. The Normal (0), HasNoEffect (1), and Blocking (2) states can be used to alter how the graph is evaluated.

The Waiting-Normal (3), Waiting-HasNoEffect (4), Waiting-Blocking (5) are for internal use only. They temporarily shut off parts of the graph during interaction (e.g., manipulation). The understanding is that once the operation is done, the state will be reset appropriately, e.g. Waiting-Blocking will reset back to Blocking.

The Normal and Blocking cases apply to all nodes, while HasNoEffect is node specific; many nodes do not support this option. Plug-ins store state in the MPxNode::state attribute. Anyone can set it or check this attribute. Additional details about each of these 3 states follow.

State Description
Normal The normal node state. This is the default.
HasNoEffect

The HasNoEffect option (a.k.a. pass-through), is used in cases where there is an operation on an input producing an output of the same data type. Nearly all deformers support this state, as do a few other nodes. As stated earlier, it is not supported by all nodes.

It’s typical to implement support for the HasNoEffect state in the node’s compute method and to perform appropriate operations. Plug-ins can also support HasNoEffect.

The usual implementation of this state is to copy the input directly to the matching output without applying the algorithm in the node. For deformers, applying this state leaves the input geometry undeformed on the output.

Blocking

This is implemented in the depend node base class and applies to all nodes. Blocking is applied during the evaluation phase to connections. An evaluation request to a blocked connection will return as failures, causing the destination plug to retain its current value. Dirty propagation is indirectly affected by this state since blocked connections are never cleaned.

When a node is set to Blocking the behavior is supposed to be the same as if all outgoing connections were broken. As long as nobody requests evaluation of the blocked node directly it won’t evaluate after that. Note that a blocked node will still respond to getAttr requests but a getAttr on a downstream node will not reevaluate the blocked node.

Setting the root transform of a hierarchy to Blocking won’t automatically influence child transforms in the hierarchy. To do this, you’d need to explicitly set all child nodes to the Blocking state.

For example, to set all child transforms to Blocking, you could use the following script. 


import maya.cmds as cmds
def blockTree(root):
nodesToBlock = []
for node in {child:1 for child in cmds.listRelatives( root, path=True, allDescendents=True )}.keys():
nodesToBlock += cmds.listConnections(node, source=True, destination=True )
for node in {source:1 for source in nodesToBlock}.keys():
cmds.setAttr( '%s.nodeState' % node, 2 )

Applying this script would continue to draw objects but things would not be animated.


Default: kdnNormal
-numberOfKnots(-nk) int createqueryeditmultiuse
How many knots to insert. At any point on the curve, there can be a maximum of "degree" knots.
Default: 1
-parameter(-p) float createqueryeditmultiuse
Parameter value(s) where knots are added
Default: 0.0
Common flags
-constructionHistory(-ch) boolean create
Turn the construction history on or off.
-curveOnSurface(-cos) boolean create
If possible, create 2D curve as a result.
-name(-n) string create
Sets the name of the newly-created node. If it contains namespace path, the new node will be created under the specified namespace; if the namespace does not exist, it will be created.
-object(-o) boolean create
Create the result, or just the dependency node.
-replaceOriginal(-rpo) boolean create
Create "in place" (i.e., replace).
Flag can appear in Create mode of command Flag can appear in Edit mode of command
Flag can appear in Query mode of command Flag can be used more than once in a command.

MEL examples

insertKnotCurve -ch on -p 0.3 -nk 2 curve1;
insertKnotCurve -ch on -nk 2 curve1.u[0.3];
// Both commands will insert two knots into curve1 at parameter value 0.3.
// Because the -ch flag is used, a dependency node is created.

insertKnotCurve -ch on -add off -p 0.5 -nk 3 curve1;
// Inserts enough knots into curve1 at parameter value 0.5 to
// achieve a knot multiplicity of 3.  Because the -ch flag is used,
// a dependency node is created.

insertKnotCurve -ch on -p 0.3 -p 0.5 -p 0.8 curve1;
// Inserts a default of one knot at each parameter value: 0.3, 0.5 and 0.8.

insertKnotCurve -ch on -p 0.3 -p 0.5 -p 0.8 -nk 2 curve1;
// Inserts two knots at each parameter value: 0.3, 0.5 and 0.8.

insertKnotCurve -ch on -p 0.1 -p 0.3 -p 0.5 -p 0.8 -nk 1-nk 2 curve1;
// Invalid command.  The number of -nk flags doesn't match the number
// of -p flags.