Overlapping Texture Coordinates


I have a segmentation of a 3D model into multiple overlapping pieces.
I calculate seams and a modulation function using my own tool and
import them into blender using a python script.

At the moment I compute four different texture maps by unwrapping four segments and
I use four uv maps to modulate the textures, i.e. the x coordinate of each
texture map is one on the segment and has a smooth fall of to zero in the region
where the segment overlaps with other segments.

Unfortunately, this way I can only display a maximum of four segments, since
I need twice the number of uv maps as I have segments.

Is there another way to have overlapping segments so that I can interpolate
any texture on overlapping parts?