Actor Michael Rooker stood in his hotel suite's bathroom staring at a coffee cup with the concentration of a jeweler inspecting a diamond.
"You want to know how I act?" he asked in his trademark deep growl before holding the cup under a running faucet.
As he fluctuated the water's force between gushing and a spitlike drip, Rooker's facial expressions told a silent story, moving from a bright smile to a grimace to a cheeky smirk.
"There!" Rooker said, as a bit of water finally crested over the cup's lip. "That was my line."
Aquatic theatrics aside, his point was simple: His performances are spontaneous, often driven by his character's...