When working with hybrid/tunable white fixtures, it can be preferable to control the color with Intensity + Crossfade channel instead of Intensity + Warm + Cool. Often, the controller does not have a control mode to do this.
A virtual crossfade would allow a single parameter to control the effective color temperature (although uncalibrated) by crossfading between two other parameters (usually warm white and cool white, but there could be applications for others).
