Part 1 in an ongoing “inside look” series on this fall’s “The Peanuts Movie.”

STEVE MARTINO knows the truth can be found by adhering to three unfussy words of wisdom:

Follow the line.

Martino, who previously found the truth in adapting the art of Theodor “Dr. Seuss” Geisel for the big screen, has the hand of a cartoonist and the mind of a visual sleuth — the artist as aesthetic detective. And so he keenly knows that to gather clues toward the truth of “Peanuts,” he must track back along the original line, to that sense of connection, because it traverses both artistic distance and time. To stay tapped into inspiration, Martino begins where the pen and brush first met paper. Like locating a lodestar, he is guided by that first contact point.

This is the journey of creating illusion from a creator’s reality. So Martino ventures to the House of Sparky.

Every day for decades, “Peanuts” creator Charles M. Schulz first put pen to paper in his Santa Rosa studio, on the board where, with the long-practiced grace of an athlete with a golden arm, the cartoonist would snap off those perfectly rounded heads and noses and ears with an efficient minimum of motion. Like some Gretzky or Federer of the boards, he saw his clean, crisply delivered lines as if operating on some higher plane of unfettered vision, and the visual result was for so long exquisite.

To make “The Peanuts Movie” in the truest spirit of Sparky, who died in 2000, Martino is adapting that iconic line that lives on like an American original. And so the director returns not only to the strip’s original art; he also makes a pilgrimage to the studio where Schulz sat and sketched and dipped that assured pen and breathed daily life into the most openly soulful characters the American comics page has ever known.

This was where he rolled up his right sleeve, on which, if you were paying attention, you could always find his heart.

Martino knows that by tracing this creative arc to Northern California, he follows the line that leads back to Sparky’s own era. So the director forges a deeper connection to the cartooning legend he never met by accepting the generous hospitality of the Schulz family — including his creative film collaborators Craig (a son of Sparky’s) and Bryan (grandson) — and soaking up the space that forever birthed this Charlie Brown world. “Standing in front of his drafting table,” Martino says, “it became my touchstone on my movie.” And likewise, the director gazes at a small monitor on which, via a VHS replay loop, we see the immortalized Schulz talking and drawing. “It’s just magical to see the characters come off his pen,” Martino will offer. So fluid, so seemingly effortless, from body to background to those facial expressions that said so much in so few lines. “They were almost like a signature for him.”

And then Martino must return to the other coast, to Blue Sky Studios in Connecticut where the film is being created and animated — and where the director is putting his own signature on the “Peanuts” experience. At Blue Sky, he must stay inspired by that California lodestar, and so it helps to bring back more than that sense-memory of the studio.

A quest is sometimes aided by something a searcher can hold in his hand. So House of Schulz creative director Paige Braddock gives Martino one of Schulz’s original pen nibs — a sword from the cornerstone. In a journey toward understanding, follow the line by studying the instrument that made the line.

And now Martino can see, he says, that Sparky “boiled down the strip to simpler and simpler form so the expression was key — the most important thing.” Boiled away by the clarity of repetition was the extraneous detail.

Martino had traveled a similar line with Seuss, leading the filmmaker to UCSD’s Geisel Library, where he held and beheld original drawings, and could detect that Geisel drew in small strokes — “from the wrists.” And now he could see how Schulz, the hockey lover, got more of his arm into the motion — into those longer, flowing, liquid strokes.

Original Schulz nib in hand, Martino spends a weekend trying to find that elusive line — and gains “a far, far greater appreciation” of what the master did.

At the center of the quest rests one question above all else:

“Where do I start the line of Charlie Brown?” Martino wondered. “It’s just one constant flow of motion. I’m much more able to find the shape with a lot of lines. His was such a beautiful commitment to that ‘simple’ line. But if you try to do it yourself, you get a page of failed attempts.” Charlie Brown as artist.

So Martino returns to Connecticut with the mission to turn Schulz’s perfect lines into perfectly authentic shapes. “The Peanuts Movie” depends on the tools of CGI (and in 3-D), but also the truth of Mr. C.M.S. And so world-class animators convert lines of face and strands of hair and black artful scratches of rain into shaded shapes that “read” as Schulz – but through the modern prism of Martino.

It is the technique of deft texture, without over-fill or overkill.

The geometry of converted Snoopy side-views must be solved, from snout to doghouse. Pigpen’s stippled dust must be adapted into smoky clouds that still feel like a comic. And Lucy’s dark hair must be highlighted so that the digitally cool illusion still radiates the warmth of the master’s hand.

And within the line followed, Martino must never lose the kinetic qualities — the imbued truth — that lie within each character. The inner spark of Sparky.

And so Martino — like his “giddy” team — wakes to each day’s challenges and rushes ahead as if the pixels were a pigskin. “I have embraced Charlie Brown on this movie more than ever before,” Martino will tell you. “It’s that never-give-up quality. Some days, you are trying to crack something and craft it, and cutting things, and you walk away at the end of day and you feel like you missed the football.”

But you know you have a relatable universe, and the support of the Schulz family and the Fox studio. “So you wake up the next day,” Martino tells you, “and say, ‘We’re going to win!’ ”

And that’s when you realize you not only have fully absorbed Charles Schulz’s drawn lines. You are also living and breathing Charlie Brown’s spoken lines.

Original Schulz nib in hand, the creative journey continues. The quest is continually propelled by the same question: Are we following the line?

And when kickoff comes in November, Team Martino gets the chance to draw one last thing to most each multiplex:

One very long line.