I am developing the engine for my client for Rise of Heroes. The game world is made up of several different islands. I was thinking it would be cool to have realistic water physics for ships and even swimming. However being a MMO pretty much all the physics will be done on the server. Is realistic Water physics something that would be to heavy to be done on the server and if so is it something that could be done on the client side where it really doesn't effect game play and would really just be there for looks to help players get into their character more. The only time I could think of that it would have a chance to effect gameplay is during Ocean warfare between guilds and or NPC Pirates if we include them. But it could just be done in a way that it doesn't affect it.

I'm not entirely sure what realistic physics you’re talking about. How would you go about putting an ocean in a game then affecting it with changes such as wind or player movement? I think the standard extra animations are more then enough and I think only a small minority would think it’s a huge plus to have realistic water in the game if it’s not a major gameplay aspect.

I am talking about buoyancy. Physics engines like Bullet has stuff for buoyancy built into them.

Oh ok, so to float or not to float. Would you really bother with actual physics though rather then just programming for say two different states? Character is either a) Swimming on the waters surface or b) swimming under the surface in the water. Boats would be easier I think, either they are sailing on the surface or your watching a fantastic animation of the boat sinking with players jumping overboard attempting to reach safety ^^

Anything impacting movement should be on the server. But for wave dynamics - I'd imagine this is better handled on the client. The only reason I can see not to delegate to the client is if the position of the waves influences the game. For example, if the boat is pitching and rolling, the waves can affect aiming (causing you to shoot higher/farther). But then again, that level of twitchyness is generally not a part of MMO gameplay.

yeah i mean, it depends on how you implement the waves. Personally i'd just scroll some noise and offset the water plane vertices, so as long as all clients are using the same noise algorithm and they are synced with the server for time, then you should be able to do all the work on the client end and still be globally synchronized.

If I played a game like that, I wouldn't notice the difference if boat on water interaction was pre-animated or calculated (especially if it's a heavy boat). So I'd put my opinion on make the water pre-animated but unaffected by the boat, and let the boat float on that with some simplistic computations.

Still, a lot of nice boat to water effects (ripples etc.) can be done on the clients' GPU's.

- Though, if this is gonna be water game with water as a huge feature then it could be cool [smile]