If anyone's interested, the Myth 2 demo is still freely available (http://tain.totalcod...i-demo-mac-os-x
), and will provide a far better illustration of what I'd like to help create than me talking for ages here
Even better, plenty of videos exist such as http://www.youtube.c...feature=related
In terms of changes that'd be required, and please bear in mind that I'm still an absolute n00b when it comes to how 0AD works, first and most obvious would be the need to allow levels that don't require resource gathering/building at all. The units you start with are the units you'd have to work with.
Less obvious are more subtle gameplay issues. The implementation of unit pathfinding and combat in Myth is far more detailed, and controllable by the player at a much deeper level, than is possible now in 0AD. Tell a bunch of units in 0AD to move somewhere, and they'll move into a formation and try and hold it while moving to the destination. When a unit gets too far out of sync with the others, it suddenly puts on a burst of blinding speed to get to where its supposed to be. When the bulk of the units arrive at the destination, any units left lagging behind stop where they are. In Myth, units only adopt the formation specified by the player (there are quite a few to choose from) when they reach the destination. In between the starting point and end point, each unit has its own path calculated independantly of the others, and there's no sudden rushing to get somewhere as each unit can only move at its set pace. Each unit will keep moving until it arrives at the destination, even if its long after the others arrive.
In 0AD, tell two groups of units to move through each other to a destination on the opposite side of the other group, and they'll meet in the middle, get stuck, then suddenly turn on their burst of speed and scatter around each other. In Myth, the units will more smoothly slide through gaps between other units, or recalculate common-sense paths around the blockage. Also in Myth, the user can click on a destination and drag the mouse to show the direction units should face upon arrival. I haven't found out yet how to do this in 0AD.
In 0AD I've seen units chase a fast target (eg a swordsman chasing a deer), and swinging his sword while quite distant from the target unit. In Myth units only use their attacks when in range. I'm sure the more I look the more differences I'll find. Watch the youtube video - you'll see units move smoothly past each other, walk around blockages or wait until a path clears, and units responding precisely to player commands during battle with everything kept under control.
If I can summarise, a Myth-like game sees units as individuals, which must obey defined limitations such as their speed, turning rate, attack distances and so on. In comparison, once units given orders as a group in 0AD their seen as members of that group, and rules are "broken" to keep the units in their place in the group or to get past obstacles. The aim of a Myth-like game is to get straight into the nitty-gritty of tactical combat, with the ability to micro-manage units & have them behave logically and predictably being paramount. In 0AD combat is less important than the resource work that precedes it, which is common to many RTS games: click the enemy and the units win or lose on their own, but never mind you can create more units.
There's obviously a lot more, such as projectiles units in Myth can pick up that give them special attacks, units that can blow themselves up damaging all others within a radius, units that can heal other units, and so on. There's also the whole multiplayer aspect, the different types of games and scoring methods. For single player there's the ability to script actions of enemy units, and determine win/loss conditions based on seizure of a destination point, or killing a certain enemy unit etc etc. There's the use of the left mouse button to select in 0AD, and the right button to tell selected units to do things. In Myth its left mouse button for both, which is very fast and intuitive, probably stemming from Myth's release for early Macs with their single mouse button. Oh, Myth has flying units as well.
After this of course is the huge task of creating the artwork; not only the maps but the new units as well.
I'm very aware of how much work creating a Myth-like game would be regardless of the engine used, and to me the first consideration is how difficult it would be to get the basics of gameplay working properly (pathfinding etc). Once thats solved I believe the project will then be feasible, and work on the remaining aspects can be planned and commenced. Btw I don't think replicating Myth is either possible or wise; just making a medieval or fantasy-based 3rd person Real Time Tactics game would be enough to start with.
Anyway, thanks for your reply Philip, I'm really impressed not only by the amazing progress you guys have made with 0AD, but also your willingness to consider adding features that might benefit other games using the engine!
Edited by slipshod, 11 May 2011 - 06:40 AM.