public void FadeOutFromOne(double duration)
        {
            if (transformationDelay == 0)
            {
                Alpha = 1;
                Transforms.RemoveAll(t => t is TransformAlpha);
            }

            double startTime = Time.Current + transformationDelay;

            TransformAlpha tr = new TransformAlpha
            {
                StartTime  = startTime,
                EndTime    = startTime + duration,
                StartValue = 1,
                EndValue   = 0,
            };

            Transforms.Add(tr);
        }
        public TransformAlpha FadeOutFromOne(double duration)
        {
            if (transformationDelay == 0)
            {
                Alpha = 1;
                Transforms.RemoveAll(t => t is TransformAlpha);
            }

            double startTime = Time + transformationDelay;

            TransformAlpha tr = new TransformAlpha(Clock)
            {
                StartTime  = startTime,
                EndTime    = startTime + duration,
                StartValue = 1,
                EndValue   = 0,
            };

            Transforms.Add(tr);
            return(tr);
        }