After all the work Valve did to clean up Counter-Strike: Global Offensive before the release of Operation Broken Fang, there are still parts of CSGO that could use some work. Recently, players reminded Valve again that something very weird was happening inside Train’s upper B halls, and it’s been happening for over a year.
When players smoke the hallway in just the right location, a bugged smoke is cut in half down and winds up giving the thrower one of the most glitched one-way smokes CSGO has ever seen. Naturally, the aging Source engine might have something to do with the bug, along with some of the tools used to create the game’s maps.
If players open the map in CSGO’s mapping program, it’s clear that Train’s brown halls have more than a few engine tools, called brushes, that intersect at this one spot. It’s possible that the notoriously picky Source engine has a weird interaction thanks to that. But it’s more likely that the train bug is a cousin of the game’s famous particle bug. CSGO’s engine has trouble rendering things right at the edge of two different particles, such as smoke and dust, and that interaction might provide an explanation for the ramp’s smoke bug.
It could also be the close cluster of engine brushes that are at fault. No one really knows for sure, except perhaps for Valve.
But this next bug takes less than a second to fix and requires almost no explaination.
Players standing at the top of ladder can often see through smokes that go off at the bottom, creating another one-way that favors Train’s T side. The ladder one-way is a direct result of a “NoDraw” brush that is so out of place, CSGO’s Hammer Editor seemed broken.
Cobwebs at the bottom of ladder are a model, and since the cobweb model doesn’t have transparency, Valve used a texture that turns things invisible to make it look like it does. Unfortunately, NoDraw textures also hide particles from smoke grenades.
Now that the two smoke bugs have gone viral, players will need to watch out for anyone on the enemy team who tries to use them. CSGO’s Source engine is full of small tricks like these, ranging from one-way smokes to precise grenade lineups.