SetKey (FCurve)

Introduced

3.0

Description

Sets the time (in frames) and value of the key at the specified index.

Note: If another key already exists at the new frame value then the method raises a 'Cannot set key' (E_FAIL) error.

If the index is out of range then the method raises an 'Invalid argument' (E_INVALIDARG) error.

If the fcurve is locked then the method raises an 'Access Denied' (E_ACCESSDENIED) error.

Scripting Syntax

    FCurve.SetKey( Index, Frame, Value, [OverrideKeyLock] )

C# Syntax

    FCurve.SetKey( Int32 in_Index, Object in_Frame, Object in_Value, Boolean in_OverrideKeyLock );

Parameters

Parameter | Type | Description
Index | Long | Index of the key. Must be a value between 0 and (number of keys - 1).
Frame | Variant | The new key time in frames.
Value | Variant | The new key value. Use a value type as follows: For standard and raw fcurves use a double value (VT_R8) For integer fcurves use a LONG (VT_I4) For boolean fcurves use a variant bool value (VT_BOOL,VARIANT_TRUE,VARIANT_FALSE).
OverrideKeyLock | Boolean | Override the FCurveKey.Locked value to force key to be removed. Default Value: false

Examples

JScript Example

    /*
       This JScript example illustrates how to use the FCurve.SetKey method
       to translate keys.
    */

    // Create a null
    Application.NewScene( null, false );
    var nullobj = ActiveSceneRoot.AddNull();

    // Create an fcurve on the posx parameter from the null
    var fc = nullobj.posx.AddFCurve()

    // Create a custom property set on the null
    var cpset = nullobj.AddCustomProperty( "CustomPSet" );
    var empty;
    var x = cpset.AddParameter( "X", siDouble, empty, siAnimatable, "X", "X", empty, 5, 0, 5 );
    var y = cpset.AddParameter( "Y", siInt4, empty, siAnimatable, "Y", "Y", empty, 5, 0, 5 );

    var fc1 = x.AddFCurve();
    var fc2 = y.AddFCurve();

    // Start editing the fcurves
    fc1.BeginEdit();
    fc2.BeginEdit();

    // Add keys to the fcurves
    fc1.Resample();
    fc2.Resample();

    // Assign some values to keys
    var val, X;

    for ( i=0; i<fc1.GetNumKeys(); i++ )
    {
       X = ( (i+1) - 10 )/10;

       fc1.GetKeyAtIndex(i).Value = Math.atan( X / Sqr( -X * X + 1 ) );

       // Copy the value to fc2 for comparison
       fc2.GetKeyAtIndex(i).Value = fc1.GetKeyValue(i);
    }

    var ckeys = fc1.GetNumKeys();
    var tangents = new Array( ckeys * 4 );
    var itan = 0;

    // Save tangents
    for ( i=0; i<ckeys; i++ )
    {
       var key = fc1.GetKeyAtIndex(i);

       // Save the tangents
       tangents[itan++] = key.LeftTanX;
       tangents[itan++] = key.LeftTanY;
       tangents[itan++] = key.RightTanX;
       tangents[itan++] = key.RightTanY;
    }

    // Translate the keys
    for ( i=0; i<ckeys; i++ )
    {
       frame = fc1.GetKeyFrame(i);
       val = fc1.GetKeyValue(i);

       key = fc1.GetKey(frame);

       fc1.SetKey( i, frame-100, val * 1.25 );
    }

    // Reset the tangents
    fc1.SetKeyTangents(tangents);

    // End editing the fcurves
    fc1.EndEdit();
    fc2.EndEdit();

    // Utility function
    function Sqr( x )
    {
       return x * x;
    }

See Also

FCurveKey.Locked | FCurveKey.Set | FCurveKey.Time | FCurveKey.Value

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