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Synopsis

smoothTangentSurface( surface , [caching=boolean], [constructionHistory=boolean], [direction=int], [name=string], [nodeState=int], [object=boolean], [parameter=float], [replaceOriginal=boolean], [smoothness=int])

Note: Strings representing object names and arguments must be separated by commas. This is not depicted in the synopsis.

smoothTangentSurface is undoable, queryable, and editable.

The smoothTangentSurface command smooths the surface along an isoparm at each parameter value. The name of the surface is returned and if history is on, the name of the resulting dependency node is also returned. This command only applies to parameter values with a multiple knot value. (If the given parameter value has no multiple knot associated with it, then the dependency node is created but the surface doesn't change.)

When would you use this? If you have a surface consisting of a number of Bezier patches or any isoparms with more than a single knot multiplicity, you could get into a situation where a tangent break occurs. So, it only makes sense to do this operation on the knot isoparms, and not anywhere in between, because the surface is already smooth everywhere in between.

If you have a cubic or higher degree surface, asking for the maximal smoothness will give you tangent, curvature, etc. up to the degree-1 continuity. Asking for tangent will just give you tangent continuity.

It should be mentioned that this is "C", not "G" continuity we're talking about, so technically, you can still see visual tangent breaks if the surface is degenerate.

Note: A single smoothTangentSurface command cannot smooth in both directions at once; you must use two separate commands to do this.

Return value

string[]Object name and node name

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

Flags

caching, constructionHistory, direction, name, nodeState, object, parameter, replaceOriginal, smoothness
Long name (short name) Argument types Properties
caching(cch) boolean createqueryedit
Toggle caching for all attributes so that no recomputation is needed
direction(d) int createqueryedit
Direction in which to smooth knot: 0 - V direction, 1 - U direction
Default: 1
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
parameter(p) float createqueryeditmultiuse
Parameter value(s) where knots are added
Default: 0.0
smoothness(s) int createqueryedit
Smoothness to get: 0 - Tangent, 1 - Maximum (based on the degree)
Default: 1
Common flags
constructionHistory(ch) boolean create
Turn the construction history on or off.
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 have multiple arguments, passed either as a tuple or a list.

Python examples

import maya.cmds as cmds

cmds.smoothTangentSurface( 'surface1', ch=True, p=0.3, d=0 )
cmds.smoothTangentSurface( 'surface1.v[0.3]', ch=True )
# Smoothes surface1 along parameter value v = 0.3. When the
# isoparm is specified, the direction and parameter value is
# implied and the "p" and "d" flags can be omitted.

cmds.smoothTangentSurface( 'surface1', ch= True, p= (0.3, 0.5, 0.8), nk=2, d=0 )
# Smoothes along parameter values v = 0.3, 0.5 and 0.8.