[jitter] Color tracking - fluid transition

Hello! im doing a installation using color tracking, the objective is to control 2  3D objects with 2 color balls. The user will be filmed with an webcam, and then while he his moving the color spheres in his hands, the objects are rotating and moving in the x and y coordinates. Till now everything is working ok, 

the only problem is when the sphere gets out of reach of the webcam, the 3D object goes to the default value in a sudden motion, i would like to know if there is any patch that can interpolate between the current value (for example 0.40)  and the default value (1.0), so the sphere can travel in a more fluid/natural motion. i explored the "line" patch, but didn't know how to get the proper result i was looking for. 

Any help will be greatly appreciated :)