Angus Cloud Went to Bay Area Album Party 3 Days Before Death

Angus Cloud was nothing but smiles a few days before he died -- which is unsettling considering he appears to have died from an overdose.

The "Euphoria" actor attended a local album release party for rap group MacArthur Maze there in the Bay Area Friday -- and he was photographed and filmed at the shindig having a good time and seemingly enjoying himself with a bunch of other people.

You never hear Angus talk in these clips ... but there's no doubt the guy was in good spirits, or at least that's how he appeared from the outside looking in any way.

The Sun reports that eyewitnesses at the party say AC was there for a few hours, and that he didn't outwardly show signs of angst or discomfort. One pal is quoted as saying Angus was happy to be home, as he'd just been in Ireland for his father's funeral.

The friend says Angus had told him he was sad. No more than 72 hours later, he was found unresponsive at his family's home in Oakland.

TMZ broke the story ... Angus died, and police had reason to believe it may have been a result of a possible overdose.

His family also hinted at him maybe taking his own life, telling us he'd been struggling to cope with his dad's passing.

We'd also been told by close family sources that he was, in fact, having suicidal thoughts prior to his passing. Angus was a rising star in Hollywood thanks to his breakout role in "Euphoria."

He was only 25.