The actor was best known, however, for his work on Descendants, having filmed the third movie in the franchise before his death. Boyce starred as Carlos, the son of Cruella de Vil, in the franchise following the children of Disney villains; fellow Disney Channel stars Dove Cameron, Booboo Stewart and Sofia Carson also star.
Following co-stars Kristin Chenoweth and China McClain, Cameron remembered Boyce in a series of Instagram videos on Tuesday, telling fans, "I felt really weird posting about Cameron on social media, because it felt really emotional and private and intimate, and social media is the opposite of that. I just couldn't quite reconcile the two, or make them fit, so I didn't know what I was gonna do."
"But I just got back from therapy, and I've decided that I think the only way to get through right now is-- I think we all need to just, if we want to, be expressive and connective, so I wrote something that I'm gonna try to read."
"The last 72 hours have felt like two weeks, and I have spent them trying to make my thoughts and feelings into words," Cameron said, reading from a sheet of paper in the black-and-white clips. "And by communicating anything that I am feeling, I have been unsuccessful. Thinking about trying to summarize something where there are no adequate words in the English language has made me ill and dizzy and I've been mostly quiet or expressing through crying. I've never stuttered or been able to speak before these last few days. My system is still in shock and my brain is still foggy and full of holes, but I'm going to try to write."
"To Victor and Libby and Maya," the actress said, breaking down in tears as she addressed Boyce's family, "you are all I can think about. My heart aches for you. I am broken for you. I have close to nothing left, which tells me some small percentage of how you must be feeling. I am so sorry, and I will never have enough words for the pain I feel and the love and the space in my heart that I hold for you."
"Cameron was one of my favorite people alive in the world, though I know that's not unique to me. Cameron was magic, an earth angel. Over the last six years, since he was only 14, Cameron talked me down from countless ledges, talked me through eating disorders, helped me out of a dark relationship and through endless breakdowns. He would whisper the dance moves to me on live television when I didn't know what I was doing, or hold my hand quietly to communicate wordlessly when we both knew we were thinking the same thing. I can't count on my hands the number of times we ruined something because we couldn't stop making each other laugh."
"Everyone keeps talking about how talented he was, and he was undoubtedly the most talented person most of us will ever know. But what was special about Cameron was who he was in the small moments, when maybe no one was looking. The moments in between the big ones, when he didn't have to be good or kind. Cameron was always good and kind. He was selfless and generous. He was magnanimous, and inarguably a true philanthropist at only 20, beloved by anyone who had ever been lucky enough to experience his light and indescribable energy. Cameron was the ultimate example of a human being."
"Goodbye, my dear, dear friend and brother," Cameron tearfully concluded in her message. "You leave behind a colossal wake, a profound chasm that can never be filled. But you also leave millions and millions of deeply impacted, hope-filled and love-filled human beings, who are who they are because of you and how you spent your brief 20 years on this Earth. What a gift you were. You turned the world on its head. We can all only hope to be half the human that you were, and you deserved so much more time. Goodbye to an earth angel. I will spend the rest of my life missing and loving you, and all the better for knowing you."
Descendants 3 is slated to debut on Disney Channel next month; it's unclear if it will air as scheduled. In a statement to ET on Sunday, a Disney Channel spokesperson called Boyce an "incredibly talented performer" who will be "dearly missed" by those who knew him.
"From a young age, Cameron Boyce dreamed of sharing his extraordinary artistic talents with the world. As a young man, he was fueled by a strong desire to make a difference in peoples' lives through his humanitarian work. He was an incredibly talented performer, a remarkably caring and thoughtful person and, above all else, he was a loving and dedicated son, brother, grandson and friend," the statement read.
"We offer our deepest condolences to his family, castmates and colleagues and join his many millions of fans in grieving his untimely passing. He will be dearly missed," the statement concluded.
A spokesperson for the Boyce family also told ET on Sunday: "It is with a profoundly heavy heart that we report that this morning we lost Cameron. He passed away in his sleep due to a seizure which was a result of an ongoing medical condition for which he was being treated. The world is now undoubtedly without one of its brightest lights, but his spirit will live on through the kindness and compassion of all who knew and loved him. We are utterly heartbroken and ask for privacy during this immensely difficult time as we grieve the loss of our precious son and brother."