you could bring the water to the horse instead as an alternative... Most of Maya's Deformers use a duplicate BaseShape strategy to calculate deformation. So, for instance if your sphere was a wrap you could slide across the surface by rotating the sphere's deform "baseShape" along with the explicit deform shape after…
@ justo sorry I should have been more explicit: a deformer with a baseShape is not the same thing as a deformer with just a shape ( although u can sometimes get luck with similar effects on some ) deformers that use base shapes have two shapes and use the distance between the shapes to calculate deformation. But when we…