Constraint (FCurveKey)

Description

Sets or returns a Boolean value indicating whether or not the specified fcurve key constraint is set. The siFCurveKeyConstraint values are of type Long (see siFCurveKeyConstraint for a list of possible values).

Warning: Getting and setting this property in Python is not supported. To set a specific constraint in Python, use the "Set" prefix with method syntax: 'fcrvkey.SetConstraint( c.siLockConstraint, true )'. This is demonstrated in the Python example below. To get a specific constraint, use the Python-compliant method FCurveKey.GetConstraint2 instead.

C# Syntax

    // get accessor
    Boolean FCurveKey.get_Constraint( siFCurveKeyConstraint in_eConstraint );

    // set accessor
    FCurveKey.set_Constraint( siFCurveKeyConstraint in_eConstraint, Boolean out_pVal );

Parameters

Parameter | Type | Description
Constraint | siFCurveKeyConstraint | The type of fcurve key constraint to set or return. You can add these values together to specify several constraints at once. For example, use siParameterConstraint + siSameLengthTangentConstraint to lock all parameters and force left and right tangent lengths to be the same.

Examples

1. JScript Example

    /*
       This example illustrates how to create an fcurve with keys and then how to set a
       constraint on one of the keys.
    */

    // ---------------------------------------------------------------------------------
    // Functions and Setup
    // ---------------------------------------------------------------------------------

    function GetConsList(fckey,setchk)
    {
       var dicConstraintTypes = new ActiveXObject( "Scripting.Dictionary" );
       dicConstraintTypes.Add( "LockParameter", siParameterConstraint );
       dicConstraintTypes.Add( "LeftRightParameter", siLeftRightValuesConstraint );
       dicConstraintTypes.Add( "G1Continuous", siG1ContinuousConstraint );
       dicConstraintTypes.Add( "LeftRightTangentDirection",       siLeftRightTangentDirectionConstraint );
       dicConstraintTypes.Add( "LeftRightTangentLength", siLeftRightTangentLengthConstraint );
       dicConstraintTypes.Add( "LockAll", siLockConstraint );
       dicConstraintTypes.Add( "HorizontalTangent", siHorizontalTangentConstraint );
       dicConstraintTypes.Add( "ExtremumHorizontalTangent",       siExtremumHorizontalTangentConstraint );
       dicConstraintTypes.Add( "AdjustedTangent", siAdjustedTangentConstraint );
       dicConstraintTypes.Add( "ZeroLengthTangent", siZeroLengthTangentConstraint );
       dicConstraintTypes.Add( "SameLengthTangent", siSameLengthTangentConstraint );
       dicConstraintTypes.Add( "NeighborTangent", siNeighborTangentConstraint );
       dicConstraintTypes.Add( "MirrorTangent", siMirrorTangentConstraint );

       var strlist = "";
       var vbKeys = dicConstraintTypes.Keys(); // the Dictionary.Keys method returns a safearray
       var jsKeys = vbKeys.toArray(); // that you can convert with the toArray() method
       for ( var k=0; k<jsKeys.length; k++ ) {
           if ( setchk == fckey.Constraint( dicConstraintTypes.Item(jsKeys[k]) ) ) {
              strlist += jsKeys[k] + " ";
           }
       }
       return strlist;
    }

    // ---------------------------------------------------------------------------------
    // Create new scene
    // ---------------------------------------------------------------------------------

    NewScene( null, false );

    // Create a null
    var n = Application.ActiveSceneRoot.AddNull()

    // Add a custompvar to the null
    var cpset = n.AddProperty( "Custom_parameter_list", false, "CustomPSet" );

    // Add a double parameter to cpset
    var x = cpset.AddParameter3( "X", siDouble, 0, -100, 100, 1 );

    // Create a fcurve on posx
    var fc = x.AddFCurve2( new Array(1,0.5), siStandardFCurve );

    var fckey = fc.Keys(0);

    // ---------------------------------------------------------------------------------
    // Set the siLockConstraint ( time, value & tangents are locked )
    // ---------------------------------------------------------------------------------

    // Set the Constraint property
    fckey.Constraint( siLockConstraint ) = 1;
    if ( fckey.Constraint(siLockConstraint) ) {
       Application.LogMessage( "fckey(" + fckey.Index + ") lock all constraints: true" );
    } else {
       Application.LogMessage( "fckey(" + fckey.Index + ") lock all constraints: false" );
    }
    Application.LogMessage( "fckey(" + fckey.Index + ") constraints set: " + GetConsList(fckey,true) );
    Application.LogMessage( "fckey(" + fckey.Index + ") constraints NOT set: " + GetConsList(fckey,false) );

    // If you try and change the key value when the lock constraint is on it raises
    // an 'Access Denied' error.
    try {
       fckey.Value = 5;
    } catch(e) {
       if ( e.number ) {
           Application.LogMessage( "fckey(" + fckey.Index + ") set value failed: " + e.description );
       }
    }

    // ---------------------------------------------------------------------------------
    // Expected results::
    // ---------------------------------------------------------------------------------

    //INFO : fckey(0) lock all constraints: true
    //INFO : fckey(0) constraints set: LockParameter LeftRightParameter G1Continuous LeftRightTangentDirection LeftRightTangentLength LockAll AdjustedTangent
    //INFO : fckey(0) constraints NOT set: HorizontalTangent ExtremumHorizontalTangent ZeroLengthTangent SameLengthTangent NeighborTangent MirrorTangent
    //INFO : 2009 - fckey(0) set value failed: Access denied

2. VBScript Example

    '
    ' This example illustrates how to create an fcurve with keys and then how to set a constraint
    ' on one of the keys.
    '

    ' ---------------------------------------------------------------------------------
    ' Functions and Setup
    ' ---------------------------------------------------------------------------------

    function GetConsList(fckey,setchk)
       set dicConstraintTypes = CreateObject( "Scripting.Dictionary" )
       dicConstraintTypes.Add "LockParameter", siParameterConstraint
       dicConstraintTypes.Add "LeftRightParameter", siLeftRightValuesConstraint
       dicConstraintTypes.Add "G1Continuous", siG1ContinuousConstraint
       dicConstraintTypes.Add "LeftRightTangentDirection",       siLeftRightTangentDirectionConstraint
       dicConstraintTypes.Add "LeftRightTangentLength", siLeftRightTangentLengthConstraint
       dicConstraintTypes.Add "LockAll", siLockConstraint
       dicConstraintTypes.Add "HorizontalTangent", siHorizontalTangentConstraint
       dicConstraintTypes.Add "ExtremumHorizontalTangent",       siExtremumHorizontalTangentConstraint
       dicConstraintTypes.Add "AdjustedTangent", siAdjustedTangentConstraint
       dicConstraintTypes.Add "ZeroLengthTangent", siZeroLengthTangentConstraint
       dicConstraintTypes.Add "SameLengthTangent", siSameLengthTangentConstraint
       dicConstraintTypes.Add "NeighborTangent", siNeighborTangentConstraint
       dicConstraintTypes.Add "MirrorTangent", siMirrorTangentConstraint

       strlist = ""
       dkeys = dicConstraintTypes.Keys()
       for each k in dkeys
           if setchk = fckey.Constraint(dicConstraintTypes.Item(k)) then
              strlist = strlist & k + " "
           end if
       next
       GetConsList = strlist
    end function

    ' ---------------------------------------------------------------------------------
    ' Create new scene
    ' ---------------------------------------------------------------------------------

    NewScene , 0

    ' Create a null
    set n = Application.ActiveSceneRoot.AddNull()

    ' Add a custompset to the null
    set cpset = n.AddProperty( "Custom_parameter_list", , "CustomPSet" )

    ' Add a double parameter to cpset
    set x = cpset.AddParameter3( "X", siDouble, 0, -100, 100, 1 )

    ' Create a fcurve on posx
    set fc = x.AddFCurve2( array(1,0.5), siStandardFCurve )

    set fckey = fc.Keys(0)

    ' ---------------------------------------------------------------------------------
    ' Set the siLockConstraint ( time, value & tangents are locked )
    ' ---------------------------------------------------------------------------------

    ' Set the Constraint property
    fckey.Constraint( siLockConstraint ) = 1
    if fckey.Constraint( siLockConstraint ) then
       Application.LogMessage "fckey(" & fckey.Index & ") lock all constraints: true"
    else
       Application.LogMessage "fckey(" & fckey.Index & ") lock all constraints: false"
    end if
    Application.LogMessage "fckey(" & fckey.Index & ") constraints set: " & GetConsList(fckey,true)
    Application.LogMessage "fckey(" & fckey.Index & ") constraints NOT set: " & GetConsList(fckey,false)

    ' If you try and change the key value when the lock constraint is on it raises
    ' an 'Access Denied' error.
    on error resume next
    fckey.Value = 5
    if Err.Number then
       Application.LogMessage "fckey(" & fckey.Index & ") set value failed: " & Err.Description
    end if
    on error goto 0

    ' ---------------------------------------------------------------------------------
    ' Expected results::
    ' ---------------------------------------------------------------------------------

    'INFO : fckey(0) lock all constraints: true
    'INFO : fckey(0) constraints set: LockParameter LeftRightParameter G1Continuous LeftRightTangentDirection LeftRightTangentLength LockAll AdjustedTangent
    'INFO : fckey(0) constraints NOT set: HorizontalTangent ExtremumHorizontalTangent ZeroLengthTangent SameLengthTangent NeighborTangent MirrorTangent
    'INFO : 2009 - fckey(0) set value failed: Access denied

3. Python Example

    #
    # This example illustrates how to create an fcurve with keys and then how to set a constraint
    # on one of the keys.
    #

    # ---------------------------------------------------------------------------------
    # Functions and Setup
    # ---------------------------------------------------------------------------------

    # Get the Softimage constants from win32com.client and error handling from pythoncom
    from win32com.client import constants as c
    from pythoncom import com_error as e

    constrainttypes = [ \
       (c.siParameterConstraint, "LockParameter"),\
       (c.siLeftRightValuesConstraint, "LeftRightParameter"),\
       (c.siG1ContinuousConstraint, "G1Continuous"),\
       (c.siLeftRightTangentDirectionConstraint, "LeftRightTangentDirection"),\
       (c.siLeftRightTangentLengthConstraint, "LeftRightTangentLength"),\
       (c.siLockConstraint, "LockAll"),\
       (c.siHorizontalTangentConstraint, "HorizontalTangent"),\
       (c.siExtremumHorizontalTangentConstraint, "ExtremumHorizontalTangent"),\
       (c.siAdjustedTangentConstraint, "AdjustedTangent"),\
       (c.siZeroLengthTangentConstraint, "ZeroLengthTangent"),\
       (c.siSameLengthTangentConstraint, "SameLengthTangent"),\
       (c.siNeighborTangentConstraint, "NeighborTangent"),\
       (c.siMirrorTangentConstraint, "MirrorTangent") ]

    def GetConsList(fckey,setchk):
       strlist = ""
       for ( c, strc ) in constrainttypes :
           if fckey.Constraint(c) == setchk:
              strlist += strc
              strlist += " "
       return strlist

    # ---------------------------------------------------------------------------------
    # Create new scene
    # ---------------------------------------------------------------------------------

    Application.NewScene("", 0)

    # Create a null
    null = Application.GetPrim("Null", "", "", "")

    # Add a custompset to the null
    cpset = null.AddProperty("Custom_parameter_list",0,"CustomPSet")

    # Add a double parameter to cpset
    x = cpset.AddParameter3( "X", c.siDouble, 0, -100, 100, 1 )

    # Create a fcurve on posx
    fc = x.AddFCurve2( [ 1, 0.5 ], c.siStandardFCurve )

    fckey = fc.Keys(0)

    # ---------------------------------------------------------------------------------
    # Set the siLockConstraint ( time, value & tangents are locked )
    # ---------------------------------------------------------------------------------

    # Notice how you have to use 'SetConstraint' for the Constraint property when setting
    fckey.SetConstraint(c.siLockConstraint,1)
    if fckey.Constraint(c.siLockConstraint) :
       Application.LogMessage( 'fckey(%d) lock all constraints: true' % (fckey.Index) )
    else :
       Application.LogMessage( 'fckey(%d) lock all constraints: false' % (fckey.Index) )
    Application.LogMessage( 'fckey(%d) constraints set: %s' % (fckey.Index,GetConsList(fckey,1)))
    Application.LogMessage( 'fckey(%d) constraints NOT set: %s' % (fckey.Index,GetConsList(fckey,0)))

    # If you try and change the key value when the lock constraint is on it raises
    # an 'Access Denied' error.
    try:
       fckey.Value = 5
    except e, (hr, msg, exc, arg):
       if exc and exc[2]: msg = exc[2]
       Application.LogMessage( 'fckey(%d) set value failed: %s' % (fckey.Index,msg))

    # ---------------------------------------------------------------------------------
    # Expected results::
    # ---------------------------------------------------------------------------------

    #INFO : fckey(0) lock all constraints: true
    #INFO : fckey(0) constraints set: LockParameter LeftRightParameter G1Continuous LeftRightTangentDirection LeftRightTangentLength LockAll AdjustedTangent
    #INFO : fckey(0) constraints NOT set: HorizontalTangent ExtremumHorizontalTangent ZeroLengthTangent SameLengthTangent NeighborTangent MirrorTangent
    #INFO : 2009 - fckey(0) set value failed: Access denied

See Also

FCurveKey.GetConstraint2

Autodesk Softimage v7.5