## FCurve.SetKey

### Introduced

v3.0

### 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.

### C# Syntax

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

### Scripting Syntax

    FCurve.SetKey( Index, Frame, Value, [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