Weight of Fire

The server does the bare minimum required to ensure all the important stuff is taken care of. While a single server could probably handily crunch the physics required, it then becomes an issue of making sure that all this physics data is sent - and remember that it has to keep running this physics simulation real-time and streaming that data as long as the physics event is in effect.

The first issue is 'a single server'. As far as dedicated servers go, every company that runs them runs multiple servers on a single machine to save money. Crunching physics increases CPU overhead and this means they have to either dedicate extra CPU cycles to that game and reduce the experience for all the other servers running on there, or limit it just like the rest, which would result in a poor-running server. It's always in a company's best-interest to keep all the fancy stuff client-side because of this. The server will understand that you shot a gun, and that it hit an object (in this case, a bucket), but it's up to your client to simulate the physics of what happens to that bucket. BF3 is especially annoying for this, as you can be lying prone and there will be boxes and **** blocking your vision, but to an enemy they aren't there at all and he can see you plain-as-day.

For rare occasions, physics will be simulated on a server, but these events are kept to a minimum and are typically fairly simple objects. If a map involves a ball, it's important to run the physics on the server so that all the clients see the ball move in the same way and can chase it. There tends to be a lot of randomness that creeps in regarding floating points when you run the same simulation on different machines. Bodies are a good example of this. For Battlefield, the server will track the physics of the torso and the torso only, because it's important for purposes of reviving players. All the limbs, the rotation, orientation of the torso are handled client-side. A body will be in the same place but appear much different.

Anyway, I digress. Point is, even if the server handily crunched the data for all the flying debris, it would have to keep streaming this information to the other players, which now translates to a fairly large bandwidth hog (which includes network cycles and tick rates).

In short, large-scale physics simulations cannot and, for the foreseeable future, will not be synced across clients. Given PA's aim for large-scale compatibility and ease of hardware requirements, I don't think they're going to try to change this.

Thanks for breaking that all down Frostiken, I have definitely been affected by those things in shooters before and I think it helped in making your point rather than digressed from it.

So with full physics calculations of that nature out would you foresee any particular issue having the simpler pre-packaged AoE effects from overkill mechanics being implemented?

The way I understand it, the server and the attacking client would register that an overkill of a particular scale was performed on a unit. Say for arguments sake there are a few classes of overkill animations made for each unit type. Then all the server would have to do is tell each client "Player 2 tank#54 overkill class 2" and the clients would play out that animation, anything caught within that animations radius could then be damaged an appropriate amount.

I don't think bandwith or calculation is such a big deal. Lots of games handle calculation of important stuff on the server side nowadays. Especially in games where it is very important that all clients have the same outcome (think MMOs, FPS and such).

I think the main issue will be responsiveness. As far as CPU cycles go, it's pretty easy (and not that costly) to handle computation on the server side. Even if you handle actual processing on the client side and have the server simply validate outcomes you are going to have to make a round trip from the client to the server (possibly using various hops). In such a case a small amount of latency will immediately break your gameplay experience.

As far as I know of the replays from FA worked fine with the WOF mods we released. Granted they were far from perfect but they did do the job.

Resin

The trick is to limit what can trigger a WOF event and then limit how far some objects can be thrown.

Example: Small unit firing on a larger unit shouldn't trigger a WOF event because of the difference in the Mass-to-Damage Ratio (MtDR) between the two units. However larger units should be able to frequently toss aside smaller units because the MtDR is heavily slanted in their favor.

Resin

Tossing a unit is just a simple matter of adding "impulse" towards a given vector, past that the unit / object would be handled by the engine. The same thing applies to projectiles, props and some special effects.

Resin

WoF works in FA's replays because the entire thing is lock-stepped and deterministic.

Will it work in other forms of replays? I have no idea. Might be, might not.

W.O.F = Awesome factor x10

My D gun would be so much satisfying if it sent the silly scout pinwheeling away in a burning hulk like some demented sagebrush across the planet. It just adds so much awesomeness at a totally unreasonable deep emotional level. I have no expertise nor knowledge in game making but I want it.

Thanks for the post first of all, I always liked the weight of impacts in TA and i have NEVER so far find anything like it in any RTS after. Thanks for putting a name to it (W.O.F).
Ever since I heard about Planetary Annihilation one of the first things that came to mind was exactly that I loved WOF and I really miss it from modern RTS, in my opinion if this game has the "annihilation" in it, it must have this feature.

Also TA had the best bomber planes ever cause of this feature, in most RTS bombers felt like laser precision snipers hitting always their target and causing damage very predictable in relation to TA where they felt like a sledge hammers, brutal destructive not always successful but always making a big bang.

I think you misunderstand WoF. WoF means a unit is knocked back when a large projectile/explosion hits is. I do not recall TA having this.

it didn't, TA units just strode into the fire and went off like firecrackers when they got hit

I think you may be referring to the effect of weapons, like making the screen shake and the massive explosions.

mmmm, yea sounds a lot like standard "battle rattle" not WOF

Looking at some real-life examples of explosive agents versus cars:

Cannon vs. car:
http://youtu.be/G97tsmSUTSM?t=20s

Dynamite vs. car:
http://youtu.be/X74bpBJCKME?t=9s

Hellfire missile vs car:
http://youtu.be/zL6OAlErkvI?t=12s

We certainly see wreckage...but usually the wreckage represents a very small portion of the overall mass of the car, with less and less wreckage the more powerful the weapon.

TA already has a mechanic where the degree of overkill plays into how big the unit exploded and how much shrapnel and wreckage was strewn about.

When will a weapon that is powerful enough to destroy a unit outright throw it around instead of vaporizing it?

chronoblip to a certain extent your correct....

Direct hits normally destroy things and throw small bits all over.

However,

Indirect hits / splash damage does throw things as the explosive wave isnt trying to push its way through or out of an object but rather pushes against it. In such cases is where WOF should apply. Even non-fatal hits can under the right conditions throw an object a considerable distance.

This is assuming that there is splash damage in PA ?

Resin

Here's a short video of WOF in action. (Created for FA)

http://www.youtube.com/watch?v=FVqMqz8PgEc

Resin

Sorry for the bump, but I do actually have something meaningful to interject here.

I like parts of this idea, and other parts not so much.

I don't think units should really be 'thrown', they're far too heavy for that. I do think there should be unit displacement, however.

It could be done in a quite simple manner, especially with the "flow fields" which are currently being implemented.

So here is a graphic:

Red/orange would be the area in which units are completely destroyed. Yellow would be where they take damage, but are not destroyed.

Within those areas there would be 2 break downs of distances at which objects are pushed (not necessarily the numbers I threw out). Units closer to the impact point would be pushed farther than units on the edges. This would leave the impact point properly void, and add the necessary 'weight' to the explosions, without being too heavy on resources.

I like this idea >.> just saying.

I think WOF is a great feature, but the OP's example video has it way overdone.

The effect would have helped suspend disbelief much more by reducing the velocity of the "ejecta" by a factor of 5 or even 10.

What Thygrrr said, plus things are more pushed (not flown) to side/horizontally, not tossed in the air like that... now I think about, it's not worth simulating the push by that point because it wouldn't destroy the unit and if it did it would look downright silly to see tanks blowing up after sliding few meters.