FPS Slowdown Concerning Boulder

[TheCollective15]

I am near the mine

Spoiler below!

where you first discover the spiders, the mine that is particuarly steamy and moist. Normally you would wander in deeper, until you hear the spider eggs cracking, and then you would take a boulder and roll it up to barricade the little arachnids. This works fine with the very first boulder, but once you come across the second one (near the broken paraffin lamp) and roll it near the entrance, the FPS plummets terribly, until you actually move the boulder right next to the entrance, when the FPS becomes normal again. This has caused me stress at least the first time I tried the level, because I was not expecting the screen to slow down, and I actually pushed the rock the wrong way during the confusion...stupid spiders...

I have an Intel Core 2 Duo E6600, 2Gb RAM, and a GeForce 7900 GS, so it is not from older hardware...and yes, I have the newest drivers installed, Thomas.

I don't think I have heard this specific bug mentioned anywhere else; if it is elsewhere on the forums, forgive me.

[Thaliur]

That exact same thing happened to me (I described it in the thread "Two weird events", along with a ghost dog sighting).

I could imagine the shattered lantern is wreaking havoc in the physics engine (hmm, that would make a great pun on the Valve boards ) when the boulder passes it.
Of course, this would only apply if the lantern pieces are "physical" and not just non.colliding decoration.
It could be graphics-related though, as this didn't happen for me when I turned the Catalyst AI up (The game looks horrible for me then, but the boulder rolls just fine)

[TheCollective15]

I could imagine the shattered lantern is wreaking havoc in the physics engine (hmm, that would make a great pun on the Valve boards ) when the boulder passes it.

That's a good hypothesis; hopefully whatever the issue is, it will make it into the patch.

[Thomas]

I will try this,

Just so I am sure, you are rolling the boulder to the hole by the broken lantern?

[Thaliur]

This was the place where it happened to me, and TheCollective's description sounds like it was that place for him, too, I'd say.

I just realised that the puddle was not on fire when I moved the boulder on my first play-through, when it was smooth, and was on fire on my second play-through when I had this framerate drop occuring.
This led me to a new hypothesis

It could be connected to lighting and the way shadows are created.
When the boulder approaches the flames, it casts a shadow on the wall behind it. then, as it touches the fire, the light source moves inside the boulder. So the algorithm that tracks the object silhouettes could get stuck finding a way out of the boulder.

[Thomas]

It is now fixed, the lantern had collision activated, and when rolling the boulder over it, the collision engine had alot of problems calculating the intersections. This resulted in the bad fps.

[TheCollective15]

Yep, the boulder by the broken lamp. Ah, so it is fixed...hope to see it in the upcoming patch!