The Melt Deformer.
Here is what the Melt Deformer looks like in action with just the default set up.
Here is how you set it up:
Like some of the previous deformers, this one is kind of a no brainer. It’s really easy to use. Put the deformer underneath the object you want to melt and then animate the “Strength” options to get it to do it’s thing. Personally I think it doesn’t look very good by itself, not saying that for the right object it won’t look good (An ice cube or slice of butter melting would work with just the defaults, for example). The trick to getting the Melt Deformer to look good would be to use it in conjunction with other deformers, use an FFD or Mesh Deformer with it and you can get some very cool results. Another good trick would be to put a restriction tag on the deformer so that you only affect a certain part of your object.
Strength – This is the most important options, this is how much the object is melted – 0% is not at all, 100% is a puddle.
Radius – Anything inside of this radius will melt slower than anything outside of it.
Vertical Randomness – This sets the amount of randomness in the vertices moving vertically.
Radial Randomness – This sets the amount of randomness in the vertices moving outward.
Melted Size – This option is the size of the object as it melts. An example being a block of ice, as it melts the pool of water left behind is larger than the orignal object. If you want the “pool” bigger, make this larger
Noise Scale – This sets a random noise to the object to make the object a little more irregular as it melts.