Hammer makes BMS (2012) acting weird

I tried to find an already existing thread about similar problems. Couldn´t find one so I created a new one. Now, I´m trying to make small changes for Black Mesa´s maps, like amplifying, changing or adding a sound. I went by these instructions to configure Hammer, step-by-step. When everything was set, I opened Hammer and started doing my changes to BMS-maps and everything went nicely. Then I ran it and things like this happened. Has anyone else faced this problem? What did I do wrong? I did similar changes to Black Mesa´s retail version and nothing like this happened, not once. Please help!

It looks like some form of visibility control is malfunctioning or not set up correctly, like possibly occluders or maybe areaportals. Are you recompiling a decompiled VMF? Decompiling isn’t a perfect science, it tends to break stuff, esp. tool brushes.

You’re using decompiled maps, so the areaportals and occluders are broken, which causes things like that to happen. You have to delete all occluders and areaportals, and remake them from scratch.

Damn, that sounds complicated. So, is decompiling origninal bsp´s the only way to edit BMS-maps in Hammer?

It isn’t that complicated, you can just disable all visgroups except areaportals and occluders, and then delete all.

For BMS 2012 mod, decompiling is the only way to edit them. We ship the retail vmfs with the retail game, but we don’t ship any mod vmfs anywhere.

Founded in 2004, Leakfree.org became one of the first online communities dedicated to Valve’s Source engine development. It is more famously known for the formation of Black Mesa: Source under the 'Leakfree Modification Team' handle in September 2004.