Ilir Beqiri discovered that he could use a gradient shader in the alpha channel of a material in C4D that would work much like the Linear Wipe Effect in After Effects.
how to create a linear, spherical or cylindrical wipe transition using a gradient shader and Xpresso setup
With a bit of work, Ilir was able to control the start and end of the gradient by moving around two corresponding nulls in the scene. Using the technique even further, Ilir discovered that he could basically use the same principle to get a spherical or cylindrical wipe, as well as another tutorial, Control the Transparency of Multiple Objects in C4D With a Single Null by Lasse Clausen that used a similar premise.
Not being discouraged, Ilir decided to create a tutorial that showed how to create a Xpresso setup that incorporates all three Wipe Transition types.
This automated and flexible system will allow you to easily switch or add any number of gradient shaders that you can control with a single null in the C4D scene.
Ilir notes that this does have some practical uses, but the tutorial is also a blueprint for an advanced Xpresso exercise. Download Ilir Beqiri’s scene files for Creating Xpresso Driven Wipe Transitions in C4D: goo.gl/j40fi3