We’re using the particle tuner here to basically set up a time test condition (very similar to how tyflow condition operators work) that tells Phoenix to gradually increase the viscosity of the liquid from 0.2 to 1.0 over time. We then setup a vray blend material that assigns an orange dry material to viscosity 1.0 and green wet material to viscosity 0.2 and the transition is a mix somewhere in between. The result is a solidifying / hardening liquid simulation which can be used as water freezing, lava hardening, plastic melting, and on and on.

More tutorials are on the way, consider subscribing: https://goo.gl/TjY9Fr