[PCF]Yaten forum post

Translation to english of the post made recently on the pk.pl forums:
1st mail. 04.05.04 13:23


Few words about patch 1.1 (I know, there are lot of bugs but it could help)

1) It’s true that you can’t move the player while on your own server and prediction is on. This is my major bug and I’ve fixed it. Problem will be resolved in 1.15 (which is going to be out within a few days or after 3 AM tonight).

Fix: On a server, prediction must not be turned on. Clients with prediction enabled can connect to the server with prediction disabled without any problems. Just run the server without prediction enabled, turn clients prediction on and it should work. Server is identical with or without prediction in this case.

2) How does prediction work? Like in QW but Havok does great change. How big? It takes as much as 20% CPU power without prediction enabled. 20ms passes, 20ms of simulation ahead, 20% more CPU usage.
If prediction is enabled:
-let’s take a 50 fps server, packet frequency 20ms and ping 100ms. Every time a packet arrives, the game must take back these 100 ms and count physics again 100ms ahead. Each 20ms we count 100ms of physics. Havok takes 5 times normal!!!
And let’s take server 100 fps and ping 200… oho.
Even in QW physics takes 5 times normal, but counting it in QW is CPU cycles we can ignore so there is no lag.

Fix: (it could be, theoretical)
We can not do anything with ping, but update from server…
Even if server sends the information frequently, we have 4 parameters: updateparams_myplayer ‘delay’, analogical updateparams_players, updateparams_physicsitems and updateparams_projectiles. ‘delay’ tells us how frequently the server sends information to the client. Without prediction it should be 0.01, because delays are smaller. With prediction enabled client does not check server so frequently, so it could be that with 0.1 or 0.2 things can run beautiful. And this means that the data from the server reaches the client only 10 times per second, Havok does not ruin our PC and fps does not drop to 2. BTW: stronger PC, better effect of prediction. 3 GHz and up, prediction is acceptable as it is, but after tweaking updateparams it could run even on 800 Mhz.
If you have big fps drops, then turn prediction off. It will not help in this case.

3) There are bugs with voting too. Game drops to desktop. We’re chasing this bug as we searching this one with final table. I cannot guarantee what will be with these bugs. One of them has been harassing us for 2 months and we cannot track it. 🙁

4) English and Polish patches were completed at the same time. Polish was put on the web and English was stopped by Dreamcatcher after additional testing. Maybe if we are not in a hurry at 3 AM because „we must release”, next patches will be free of bugs.

2nd mail. (2 minutes later)

Aha, I think that Adrian will murder me for public statements. Why in this thread? Why on this webpage? Why not on other sites? Who is going to take offence? etc. It’s why I am giving hints here. Well. I don’t have time , I’m writing code, fixing bugs and I’ve read this thread by accident. It could be any other place where people talks about PK bugs.
3rd mail 04.05.04 18:17

I think you’ll not be worried if I tell you that we test here on 1.8 GHz machine. It was high end machine when we were starting project. 🙂
Probably bug with desynchronization of server and client after 10 minutes of gaming on same map has been removed. With a large amount of effort but its effective. We see this while testing. 🙂 Unfortunately QW solution is now not possible. Too much to change. I’ll think about it later.

If it works on 3 GHz I am glad. Here we test it on LAN and it works great so far.

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