Morphing is a feature which allows you to modify mesh objects in real-time. The most common use case for this feature is facial animation. Morphing also suits well to creating parametric objects which can interactively change their dimensions, shape, thickness, holes, profiles etc.
See the following demo as an example:
In 3ds Max, add a Morpher modifier, and setup the channels for morph targets. Please notice that due to hardware constraints, the total number of active shape keys is limited to 6. During rendering, the engine selects 6 shape keys with largest influences ignoring all excessive shape keys.
Controlling via Puzzles
To manipulate your morph targets in real-time there are two puzzles: get morph factor and set morph factor. See the demo called "Parametric Models" for more details.
Feel free to ask on the forums!