A while ago I tried to deform one geometrical object with another. The source object would deform by using the blend shapes and the target object should deform accordingly. Unfortunately as soon as I would activate the blendshape the target mesh completely exploded.
After a while I figured out that Maya doesn’t like small faces very much an creates floating point errors in the calculation. Seeing as I dint have any access to the code with the Maya api I decided to look for a simple workaround.
Simply up scaling the model solved the problem. But as long as you either have a lamina face or a face that has a surface of a decimal number the geometry influence will explode.