PixelAffair shows how to create a setup that can turn objects into molten metal using the Volume Builder in Cinema 4D.
Check out this tutorial from Ghana-based Pixel Affair that shows how to create the effect of molten metal taking over an object. The effect uses the Volume Builder toolset in Cinema 4D as the foundation for the animation.
Pixel Affair shows how to work with Vertex Maps to control the advance of molten metal animation.