By . Daily Mail Reporter . PUBLISHED: . 15:36 EST, 22 January 2014 . | . UPDATED: . 17:41 EST, 22 January 2014 . Robert De Niro has purposefully kept his private life out of the public eye for decades but now he has broken that trend by revealing all in a new documentary about his artist father. The new HBO documentary that premiered at Sundance Film Festival reveals that the reason why the legendary actor’s father left his mother when the boy was only 3-years-old was because he realized that he was gay. De Niro, who was named after his father Robert De Niro Sr, narrates much of the film and reads directly from his father’s personal journals wherein he grapples with his sexuality in a less accepting time. Son and father: Robert De Niro has produced a documentary about his father Robert De Niro Sr (right, seen together before his 1993 death) Out in the open: De Niro, seen with producing partner Jane Rosenthal (left) at Sundance on Sunday, said that he first wanted to do the film just for his family but then decided his father's artistic career was worth sharing . The two-time Academy Award winner said his father, who died in 1993 from prostate cancer, may never have resolved the issues that he had with God as he came to grips with the realization that he was gay. Robert De Niro Sr. reportedly had an amicable split from his wife, and remained a constant presence in his son’s life as they all continued living in New York City. 'I did this for him,' De Niro told the audience at the premiere in Utah on Sunday. 'I wanted my younger kids- who were born after he died- to know what their grandfather did. I even kept his painting studio intact so they could see it.' Artists: While his father (seen left, in an undated photo), who realized later in life that he was homosexual, was a painter, Robert (right) chose acting as his form of expression . Sign of the times: The elder Mr De Niro was a figurist painter, as his son is seen standing next to one the many works of art on display in international museums . De Niro has six children, four of whom were born after their grandfather died in 1993- including one who was born in 2011 via surrogate. The actor's two children from his first marriage to Diahanne Abbott- his eldest son, Raphael, and her daughter from a previous relationship that De Niro adopted- both met their grandfather. De Niro Sr. became known in some New York circles in the 1950s and 1960s for his influential work in the abstract expressionist movement. He went on to hold chaired professorships and has works displayed as part of the permanent collections at renowned museums like the Hirschorn, the Brooklyn Museum and the Baltimore Museum of Art, but he never quite achieved the same level of celebrity as some of his contemporaries like Willem de Kooning and Jackson Pollack. Though the documentary clearly comes two decades after his death, his son was eventually convinced that it is more than just a family story. Family affair: De Niro, seen here at the Kennedy Center Honors ceremony in 2009, said that he wanted to make the film for his children who did not get a chance to meet his father (seen with three of his six children and his wife Grace Hightower) 'Originally, Bob wanted to make the film . just for his family. But then we realized it tells the story not just of . Robert De Niro's Sr.'s work- which is amazing- but the entire art world . of the time,' director Perri Peltz told The Hollywood Reporter. While Robert Sr.'s works emerged during post World War II, when abstract expressionism became popular, his style was not described in the same way. It was often considered figurist, depicting still life 'in simple set-ups with no pretension,' as described in the half-hour documentary. Paternal bond: Bradley Cooper, who has called De Niro one of his most meaningful mentors, made a low-key entrance as he slipped in to watch the premiere of the documentary at Sundance (seen together at the SAG Awards) He became increasingly disconnected from the abstract expressionist movement, inspired more by early 20th century French artists like Henri Matisse. 'He was very clear about what he thought was art and what he liked, and yet at the same time he was generous. People can appreciate things, it doesn't matter if the aesthetic can be different from yours,' De Niro told Reuters at the film's premiere. 'He didn't feel that certain things art-wise were art. It was another thing that wasn't enough for him, and his own style as you see was always the same. It varied some but not a lot.’ Though the father-son duo were close, there was a shift as De Niro's acting career took off since hist his father felt somewhat resentful that his own work had never been recognized by a bigger audience. For De Niro, the documentary, scheduled . to air on HBO this summer, serves as an homage to his father, whose . paintings are still shown in galleries around the world, and also as a . memory for his own children. 'I realized how important it is for . children to appreciate certain things (their parents) want to share with . them,' an emotional De Niro says in the film. De Niro founded the TriBeCa Film Festival in his hometown of New York City but he wanted to bring the documentary to Sundance to make sure the spotlight was fully on the works and memory of his father. 'We were really thrilled that it was chosen for Sundance because it separates from having it at Tribeca and we see Bob's father's works on its own in a different setting than you would in New York,' producer Jane Rosenthal said.
Robert De Niro produced and narrated a new documentary about his artist father who left his mother when he was only 3-years-old .
He only discovered later that the marriage crumbled because his father realized that he was homosexual .
Robert and his father, Robert Sr, remained close until his death in 1993 .
Now he has released a documentary about his father and it premiered at the Sundance Film Festival .
His father was a well-known artist but never achieved the same success as his contemporaries like Jackson Pollock or Willem de Kooning .
By . Daily Mail Reporter . PUBLISHED: . 15:36 EST, 22 January 2014 . | . UPDATED: . 17:41 EST, 22 January 2014 . Robert De Niro has purposefully kept his private life out of the public eye for decades but now he has broken that trend by revealing all in a new documentary about his artist father. The new HBO documentary that premiered at Sundance Film Festival reveals that the reason why the legendary actor’s father left his mother when the boy was only 3-years-old was because he realized that he was gay. De Niro, who was named after his father Robert De Niro Sr, narrates much of the film and reads directly from his father’s personal journals wherein he grapples with his sexuality in a less accepting time. Son and father: Robert De Niro has produced a documentary about his father Robert De Niro Sr (right, seen together before his 1993 death) Out in the open: De Niro, seen with producing partner Jane Rosenthal (left) at Sundance on Sunday, said that he first wanted to do the film just for his family but then decided his father's artistic career was worth sharing . The two-time Academy Award winner said his father, who died in 1993 from prostate cancer, may never have resolved the issues that he had with God as he came to grips with the realization that he was gay. Robert De Niro Sr. reportedly had an amicable split from his wife, and remained a constant presence in his son’s life as they all continued living in New York City. 'I did this for him,' De Niro told the audience at the premiere in Utah on Sunday. 'I wanted my younger kids- who were born after he died- to know what their grandfather did. I even kept his painting studio intact so they could see it.' Artists: While his father (seen left, in an undated photo), who realized later in life that he was homosexual, was a painter, Robert (right) chose acting as his form of expression . Sign of the times: The elder Mr De Niro was a figurist painter, as his son is seen standing next to one the many works of art on display in international museums . De Niro has six children, four of whom were born after their grandfather died in 1993- including one who was born in 2011 via surrogate. The actor's two children from his first marriage to Diahanne Abbott- his eldest son, Raphael, and her daughter from a previous relationship that De Niro adopted- both met their grandfather. De Niro Sr. became known in some New York circles in the 1950s and 1960s for his influential work in the abstract expressionist movement. He went on to hold chaired professorships and has works displayed as part of the permanent collections at renowned museums like the Hirschorn, the Brooklyn Museum and the Baltimore Museum of Art, but he never quite achieved the same level of celebrity as some of his contemporaries like Willem de Kooning and Jackson Pollack. Though the documentary clearly comes two decades after his death, his son was eventually convinced that it is more than just a family story. Family affair: De Niro, seen here at the Kennedy Center Honors ceremony in 2009, said that he wanted to make the film for his children who did not get a chance to meet his father (seen with three of his six children and his wife Grace Hightower) 'Originally, Bob wanted to make the film . just for his family. But then we realized it tells the story not just of . Robert De Niro's Sr.'s work- which is amazing- but the entire art world . of the time,' director Perri Peltz told The Hollywood Reporter. While Robert Sr.'s works emerged during post World War II, when abstract expressionism became popular, his style was not described in the same way. It was often considered figurist, depicting still life 'in simple set-ups with no pretension,' as described in the half-hour documentary. Paternal bond: Bradley Cooper, who has called De Niro one of his most meaningful mentors, made a low-key entrance as he slipped in to watch the premiere of the documentary at Sundance (seen together at the SAG Awards) He became increasingly disconnected from the abstract expressionist movement, inspired more by early 20th century French artists like Henri Matisse. 'He was very clear about what he thought was art and what he liked, and yet at the same time he was generous. People can appreciate things, it doesn't matter if the aesthetic can be different from yours,' De Niro told Reuters at the film's premiere. 'He didn't feel that certain things art-wise were art. It was another thing that wasn't enough for him, and his own style as you see was always the same. It varied some but not a lot.’ Though the father-son duo were close, there was a shift as De Niro's acting career took off since hist his father felt somewhat resentful that his own work had never been recognized by a bigger audience. For De Niro, the documentary, scheduled . to air on HBO this summer, serves as an homage to his father, whose . paintings are still shown in galleries around the world, and also as a . memory for his own children. 'I realized how important it is for . children to appreciate certain things (their parents) want to share with . them,' an emotional De Niro says in the film. De Niro founded the TriBeCa Film Festival in his hometown of New York City but he wanted to bring the documentary to Sundance to make sure the spotlight was fully on the works and memory of his father. 'We were really thrilled that it was chosen for Sundance because it separates from having it at Tribeca and we see Bob's father's works on its own in a different setting than you would in New York,' producer Jane Rosenthal said.
revealing all in a new documentary about his premiered at Sundance Film Festival reveals that his mother when the boy was only 3-years-old was because he realized that he was gay. De Niro, who time. Son and father: Robert De Niro has produced a documentary about his father Robert De Niro Sr he was homosexual, was a painter, Robert (right) never quite achieved the same level of celebrity as some of his contemporaries like Willem de