Game Development Community

Does TGB now have fixed ticks?

by John Klimek · in Torque Game Builder · 01/09/2007 (9:04 am) · 13 replies

In a thread over at the TorqueX forums, Clark Fagot mentioned that T2D now had a fixed tick-rate but he wasn't completely sure if Melv had implemented it yet.

So I'm wondering if the latest version of TGB does in-fact have fixed ticks.

Also, just to confirm what Chris said, if TGB now has fixed-ticks, will I be able to support multi-player Scorched Earth/Worms?

What I mean, is that I can have one client say "send a projectile at 30 degrees with 100 power" and simply tell the same thing to the other clients and I be certain every client will have the exact same collisions, etc, etc.

Thanks!

- John

#1
01/09/2007 (1:17 pm)
It is my opinion that sending "30 degrees, strength 100" will never be enough to have 100% identical deterministic results on every machine unless you write your own math library. This is not specific to TGB, this is for any engine that has not implemented its own math library for doing even the simplest of arithmetic. I also believe it is possible to do multiplayer scorched in TGB without fixed ticks.

I would approach this problem by calculating the projectile path on one machine, then sending the start point, apex, and impact spot over the wire and interpolating between those with a spline curve or other algorithm. You can send these points from launching machine or from a central server (to prevent hacks/cheats).
#2
01/10/2007 (4:40 pm)
TGB releases do not have tick based physics yet.
#3
01/10/2007 (5:50 pm)
Any idea when tick-based physics will be implemented? (is it already implemented into TorqueX?)

Also, what benefit does tick-based physics have? I don't understand the whole thing except that I was told that having tick-based physics should make the simulation much more deterministic (eg. reliable and repeatable).
#4
01/13/2007 (10:50 am)
To summarize :
When it's time based the delta Time fluctuate so the physics simulation isn't reliable and depend of the computer processing power.
When it's tick based it use a step by step delta which should be the same on every computer.

It won't solve your ballistics problems but this will stabilize simulations (mainly for stack and "go crasy" bug when the app loosing focus).

I maybe wrong since i forgot a bit about RigidBody or SoftBody simulations since nobody could release something usable for the mass.
Something like Flatland (http://flatland.sourceforge.net/) would have been perfect but the project is dead and need speed optimizations.
#5
01/22/2007 (4:10 pm)
Quote:Any idea when tick-based physics will be implemented?

What I can say is that we have tick based physics running in a TGB version. From what I understand it fixes some physics issues and stability issues. What I can't say is when we will release it and how extensively it has been tested (honestly don't know the later and the former will probably be soon, though we try and not make promises on released features unless we can garantee them :).
#6
01/31/2007 (10:21 am)
What i can say is that a feature listed into the TGB product page since the beginning, the main feature of my project too but sadly i'll have to forget it :(
#7
02/01/2007 (6:42 am)
Posts like that are the reason we can't make statements about release dates.
#8
02/01/2007 (10:23 am)
This wasn't a remark statements about release dates at all.

Try to understand your customers. I've buy TGB because it's the only 2D engine who claim having a Rigid Body Dynamics system since the beginning. And years after you still can't use it in many situations !

It's the way i choose to inform you that some of us are disappointed on this feature.
You should not reject the fault on us like that.
#9
02/01/2007 (11:01 am)
Quote:What i can say is that a feature listed into the TGB product page since the beginning

"tick-based physics" has been? Where?
#10
02/02/2007 (11:47 am)
In any case, Justin confirmed it in a comment to this .plan:
Quote:@Dustin : we DO plan to introduce fixed-timestep physics during this Beta. For sure. :)
#11
02/02/2007 (12:51 pm)
This is great news! Thanks for the update!!
#12
02/03/2007 (1:24 am)
Quote:"tick-based physics" has been? Where?
Working and stable Rigid Body system.
As far as it working i don't care if it's tick based or not you understand ?
#13
02/03/2007 (5:47 am)
@Rivage - I wasn't passing the buck at all. I was just stating the undeniable fact that when you announce a feature, your customers hold you to it, as you clearly demonstrated. It wasn't meant as a negative comment at all. I understand our customers to the extent that I expect them to demand whatever we promise to deliver. I wouldn't have it any other way. Unfortunately, that doesn't lend itself well to completely transparent development because everyone using TGB has their own idea of what should be changed first (and that includes us here at GG).

Aside from that, picture a scenario where it comes to our attention that ticked physics introduced some critical bug into TGB and we can't release until it's fixed. If we announce now that ticked physics were going to be in the next release and it got held back to allow us time to properly test it, people would go nuts. I've seen it happen tons of time and it's frustrating on both sides of the fence because, believe it or not, we all want TGB to be as great as possible as soon as possible.

Also, the first TGB release was much less than a year ago. It certainly hasn't been out for years, as you're suggesting. It's still very young tech and we are far from finished improving it. I think you'll be very pleased with the changes coming down the pipe in future releases.