SAN FRANCISCO — Artist Thomas Kinkade once said that he had something in common with Walt Disney and Norman Rockwell: He wanted to make people happy. And he won success with brushwork paintings that focused on idyllic landscapes, cottages and churches — highly popular works that became big sellers for dealers across the United States. The self-described “Painter of Light,” who died Friday at age 54, produced sentimental scenes of country gardens and pastoral landscapes in dewy morning light that were beloved by many but criticized by the art establishment. Kinkade died at his home in Los Gatos in the San Francisco Bay Area of what appeared to be natural causes, said family spokesman David Satterfield.