Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Already on GitHub? Sign in to your account

Bringing back old-style com_fixedTic, adding Carmack's reverse as a compile option #59

wants to merge 2 commits into


5 participants

meklu commented Jan 3, 2013

These commits bring back the pre-patch behaviour where setting com_fixedTic to -1 unlimits the framerate while still somewhat keeping everything in sync. (com_fixedTic 1 would make the physics engine go super fast in addition to the framerate, and this is undesirable.) This should help people with, say, 120Hz monitors.

Another feature that was added was the option to compile the engine to use Z-fail in its shadow rendering. This is off by default.

motorsep commented Jan 3, 2013

what's the point of adding patented method? It's not much faster and actually could be slower at times, is what I was told. It makes more sense to add shadowmapping instead.


andre-d commented Jan 3, 2013

I agree with motorsep, the results of the opensource method will be nearly identical...and you get to avoid any possible legal issues.


DanielGibson commented Jan 4, 2013

Hi, thanks for the code :)
I'll have test it and I'm not sure if I wanna add the patented method, will probably discuss that with dhewg.

"It makes more sense to add shadowmapping instead." adding zfail is ~10 lines of code, shadowmapping is a lot more work.. so it's not really comparable

meklu commented Jan 4, 2013

@DanielGibson: Yeah, the Z-fail thing would probably have deserved its own pull request, what with it being of slightly questionable legality (here being implemeted as a run-time toggle, making binaries nigh-impossible to distribute).

@motorsep: I haven't run any benchmarks comparing the two different methods, so I can't really comment on their performance. edit: Also, shadowmapping sounds a bit more demanding a task, especially for someone like me who's only first looked at id engines right after purchasing a copy of Doom 3 last weekend, and isn't very experienced in graphics programming (I've cooked up a couple of silly fragment shaders for itty bitty projects, but that's about it).

The cvar change is a bit nicer all round though, but it might have to be flagged as a cheat for multiplayer stuff, since the physics engine is a slight bit dependent on the tickrate (since the entire engine expects 60Hz) and might result in odd behaviour. -1 keeps things in sync pretty well though, and I can't really see a difference between it and 0, so it should at least be useful in single player.

Any chance for the com_fixedTic command to allow -1 again for 60+ FPS?

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment