Sets or returns the left tangent Y of the fcurve key as a Double. The left tangent Y value is a negative offset from the current FCurveKey.Value.

The left tangent of the first key and the right tangent of the last key cannot be changed; if you try to set the tangent for one of these the property does nothing and returns S_FALSE in C++.

Tangent values only apply to standard function curves (where FCurve.Type = siStandardFCurve), the tangent value 0 is returned for all other function curve types defined by siFCurveType.

// get accessor Object rtn = FCurveKey.LeftTanY; // set accessor FCurveKey.LeftTanY = Object;

JScript Example

/*
	See FCurveKey.LeftTanX for JScript, VBScript and Python examples using this property. 
*/

FCurveKey.LeftTanX FCurveKey.RightTanY FCurveKey.RightTanX FCurve.SetKeyTangents