Half-Life celebrated its 25th anniversary last Sunday, and Valve laid out a buffet of Lambda-shaped treats to mark the occasion. The company added new multiplayer maps to the game, released an hour-long documentary delving into its design, and fixed a few of its most resilient bugs. But there's one bug that escaped Valve's digital butterfly net, one that, weirdly enough, is actually seen in the 25th anniversary documentary. Now, it's been fixed.
The bug appears in the Half-Life's "Blast Pit" chapter, which sees Gordon Freeman trying to dislodge a trio of alien tentacles from a rocket-engine testing silo. During the chapter's opening, there's a famous sequence where a tentacle smashes through the protective glass of the silo's control room, slams a scientist against the back wall, then drags them screaming back through the window to a grisly demise. But as you can clearly see in the documentary, the animations don't quite line up, and the scientist sort-of floats through the window underneath the tentacle.
Hardly a huge problem, but nonetheless an unsightly glitch in one of Half-Life's most iconic scenes, one that's been present in the game for 25 years. Since appearing in the documentary, however, the issue has been resolved, as shown in this video posted on not-Twitter by user Vinícius Medeiros.
Understandably, there was some speculation as to whether there was a causal link between the bug's appearance in the documentary and its resolution. Noclip's Danny o'Dwyer, who worked with Valve to create the doc, quote-tweeted Vinícius saying "me putting the broken version of this in the doc may be somewhat responsible. Sorry Valve engineers!"
However! As noted by o' Dwyer in a follow-up tweet, it appears that fixing the bug was Valve's plan all along. O' Dwyer links to the Mastodon account of Valve programmer Ben Burbank, who provides a detailed breakdown of both how and why the bug was fixed. "We wanted to fix this for the 25th Anniversary Update but other stuff took priority pre-ship", Burbank says. He also points out that "it's not a systemic bug and seems largely to be isolated to this cutscene."
Burbank goes on to explain that the bug occurs because it's the only cutscene in Half Life "that seems to depend heavily on syncing a bunch of animations". According to Burbank, the three options for fixing it were to attempt a code fix, change the animations that play in the scene, or change the map itself.
Valve opted for the third option. "If we fixed the sequence so that the scientist timing worked out, a player could still stand in the doorway and shoot the scientist, interrupting the sequence, and then he would play his animation in an insane way," Burbank explains. "Hence, I just hex edited the map. Triggering the animation on the door opening…instead of when the player walks through the door ensures the player can't shoot the scientist before things start "syncing". The sequence is SLIGHTLY different, but plays more closely to what the alpha maps ran when this was authored."
So, now you can watch this Black Mesa boffin bite it in the way Valve always intended. It's not surprising Half-Life has so many eagle-eyes on it right now. The 25th anniversary update has caused a huge surge in its player-count, which also means now is a great time to dive back into chaotic multiplayer.
