Using light to blend materials/textures

This is my first post on the polycount boards though I have admired many of polycounts artists from a distance for some time and I'm hoping to share some of my work soon as well.

I was wondering if anyone knows of a method in 3dsmax of using 3d lights to alternate the texture or material of an objects surface.

For a while, I've been using the ink and paint material and creating two seperate textures for the regular diffuse and shaded slot. However this presents a limitation in that there is a stark transition between between the two textures and what I'm looking for is a method where the areas of the object where the light begins to fall off would create a gradual fade between the two textures.

Any advice would be appreciated.

Thanks,
DoomiVox