Left 4 Dead - Multicore Rendering Crash?

So, okay. This is probably an oddly specific issue, but I’ve found nothing about it on Google and I’m clueless as to what could be causing this.

A few months ago, I was bored and started working on an L4D campaign, based off of the early-2000’s City 17 concepts for HL2, to brush up (no pun intended) on my Hammer skills. The third map is based on some really early WC maps of the C17 underground/canals, and at one point the player wades through a sort of large storm drain series of pipes.

I’ve created a reflective water texture for the campaign, but I’ve already looked into that and determined it’s not part of the issue here.

So, problem: The rest of the map works fine. However, in the pipes, when there are a multitude of infected, the game tends to crash to desktop. Disabling multicore rendering “fixes” the issue, but I’m stumped as to why it happens in the first place. There’s a noticeable spike just before crashing in Mat_ThreadedEndFrame according to the showbudget panel. This crash only happens on L4D1, as well - L4D2 copes perfectly fine, with or without multicore rendering.

Things I’ve tried:

  • Using another water material, in case the reflections were somehow responsible - No result
  • Adding a func_ragdoll_fader - Prevents crashing, but it looks pretty terrible to have the ragdolls just vanish like that, so I’d rather not do this if possible
  • Adding a func_radoll_fader and killing it at the beginning of the map - I can’t remember what gave me this idea, but it seemed to work for a while before it started crashing again
  • Changing the height of the water - No result, IIRC
    Does anyone know of a way for me to fix this without getting rid of the water or using a ragdoll fader, or is there nothing to be done about it?

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