I doubt many people in Zilker Park at the 2016 Austin City Limits Festival realized the long-haired man joining Mickey Raphael on harmonica duty during Willie Nelson’s “Roll Me Up and Smoke Me When I Die” was a future Nobel Prize-winning scientist.

Leave it to a kid who spent part of his childhood tapping into his love of science to create bombs to blow up our image of a scientist.

It seems they broke the mold with Dr. Jim Allison, the Alice, TX native and groundbreaking scientist profiled in filmmaker Bill Haney’s documentary, “Breakthrough,” which made its world premiere Saturday at South by Southwest.

Haney’s documentary takes a fairly standard chronological look at the early years of Allison’s life, growing up the hard-headed and mischievous youngest of three brothers. The rote format works in this case, as most viewers will likely need an introduction to the subject’s life. Allison’s childhood, and the rest of his life and work, would be informed by the loss of his mother to cancer when Allison was just 11-years old.

Following a childhood spent exploring and pushing back on teachers that didn’t appear his intellectual equal, Allison eventually graduated from the University of Texas in the late 60s, where his love of science and books was equaled by his love of music and good times.

The free spirit eventually landed in San Diego, a stint which doesn’t serve the movie much outside of an awesome Willie Nelson anecdote, and would have a career that saw him spending time working in Smithville, Berkeley, CA and New York City. During that time, Allison made some fascinating discoveries about T-cell development and CTLA-4 that would lead to the development of immuno-oncology drugs that have been used to successfully treat almost a million cancer patients.

His research and hypothesis were often met with pushback from the scientific and pharmaceutical communities, but Haley’s doc shows that the independent-mindedness and creativity that marked Allison’s childhood are the same characteristics (along, undoubtedly with some inherent genius) that propelled him toward one of the great scientific discoveries of the 20th and 21st centuries, along with the Nobel Prize.

Fellow outsized Texas character Woody Harrelson’s voice appears to guide the film through the scientific details of Allison’s research, giving a layman’s vibe and simplicity to dense material, while former colleagues, reporters, Allison’s ex-wife and friends help paint a picture of a charismatic, dogged and passionate man whose right and left-brains seem to fire with equal intensity.

Haley weaves into the narrative a story of a cancer survivor saved by Allison’s discoveries, though the sly way in which he attempts to pay off the touching angle could have benefited from a more direct telling.

The film stays more or less on the surface of what must have been a surely fascinating life, skimming over details of the sacrifices demanded of Allison and his loved ones (his son’s almost non-existence is a bit confusing), but it does good work of revealing a colorful character whose contributions to science and the modern world make him a first ballot Texas Hall of Famer on par with other greats like his pal and fellow Outlaw legend Willie.

“Breakthrough” screens again Thursday at 8:45 p.m. at Zach Theatre, and I imagine it will not be hard for the general public to purchase tickets.