On a Saturday morning 30 years ago, Dennis Constance left home early. Wearing a tattered T-shirt and jeans, Constance was going to be in “The Day After,” the made-for-TV film about nuclear fallout. The movie was being filmed in Lawrence and ABC was in need of actors. Extras, mainly, that would play bit parts, looking scruffy and in some cases sick and horrified.

On Thursday evening, Constance and other former cast and crew members gathered at Watkins Museum for a 30th reunion. About 50 people popped into the museum to view an exhibit and swap stories.

Thirty years ago in August, production for “The Day After” began. Most extras were Lawrence residents. Their instructions were simple: look dirty.

Constance listened well. When he arrived, a crew inspected him, approved his appearance and gestured him to the set. Those who weren’t mussed enough were told to roll in the dirt. Others were doctored with movie makeup, given scars and burns and, in some cases, asked to shave their heads.

The batch of extras who transformed their appearance fetched $40 to $75. But most happily worked for free. For the extras, making the movie involved a lot of waiting. In between scenes, they would stand, chat and eat.

Larry Brow ate a lot of hot dogs, plucked and assembled from the steaming buffet tables, that day. He was in a hospice scene filmed at Allen Fieldhouse and he remembers becoming depressed when the director announced, through a booming megaphone, that they were going to die.

Mark Batesel was in a few scenes. For one of them, he had to sit in his car on K-10 for 10 hours. It was a painfully boring day. And the studio neglected one need: bathrooms. Every now and then people would climb from their cars and dart into the weeds.

That morning 30 years ago, Constance had made arrangements for his wife to watch their 1-year-old son. He thought he would be gone a long time. He didn’t expect, however, to be gone until midnight. A long day. But worth it. In his movie collection at home is a copy of “The Day After.” When his scene rolls around, he can point to himself.

“(The movie) is a part of Lawrence’s history and it’s a part of my history,” he said.

“The Day After” will be shown at 1 p.m. Saturday at the Spencer Museum of Art, 1301 Miss.